Advanced glycation end-product expression is upregulated in the gastrointestinal tract of type 2 diabetic rats

AIM:To investigate changes in advanced glycation end products(AGEs) and their receptor(RAGE) expression in the gastrointestinal(GI) tract in type 2 diabetic rats.METHODS:Eight inherited type 2 diabetic rats GotoKakizak(GK) and ten age-matched normal rats were used in the study.From 18 wk of age,the body weight and blood glucose were measured every week and 2 wk respectively.When the rats reached 32 wk,twocentimeter segments of esophagus,duodenum,jejunum,ileum,and colon were excised and the wet weight was measured.The segments were fixed in 10% formalin,embedded in paraffin and five micron sections were cut.The layer thickness was measured in Hematoxylin and Eosin-stained slides.AGE [N epsilon-(carboxymethyl) lysine and N epsilon-(carboxyethyl)lysine] and RAGE were detected by immunohistochemistry staining and image analysis was done using Sigmascan Pro 4.0 image analysis software.RESULTS:The blood glucose concentration(mmol/L) at 18 wk age was highest in the GK group(8.88 ± 1.87 vs 6.90 ± 0.43,P 0.001),a difference that continued to exist until the end of the experiment.The wet weight per unit length(mg/cm) increased in esophagus,jejunum and colon from the normal to the GK group(60.64 ± 9.96 vs 68.56 ± 11.69,P 0.05 for esophagus; 87.01 ± 9.35 vs 105.29 ± 15.45,P 0.01 for jejunum; 91.37 ± 7.25 vs 97.28 ± 10.90,P 0.05 for colon).Histologically,the layer thickness of the GItract was higher for esophagus,jejunum and colon in the GK group [full thickness(μm):575.37 ± 69.22 vs 753.20 ± 150.41,P 0.01 for esophagus; 813.51 ± 44.44 vs 884.81 ± 45.31,P 0.05 for jejunum; 467.12 ± 65.92 vs 572.26 ± 93.60,P 0.05 for colon].In esophagus,the AGE and RAGE mainly distributed in striated muscle cells and squamous epithelial cells.The AGE distribution was much stronger in the GK group compared to the normal group both in the striated muscle layer and mucosa layer(immuno-positive area/ total measuring area %:4.52 ± 0.89 vs 10.96 ± 1.34,P 0.01 for muscle; 8.90 ± 2.62 vs 22.45 ± 1.26,P 0.01 for mucosa).No visible difference was found for RAGE distribution between the two groups.In the intestine AGE and RAGE distributed in epithelial cells of villi and crypt.RAGE was also found in neurons in the myenteric and submucosal plexus.The intensity of AGE staining in mucosa of all segments and RAGE staining in neurons in all segments were strongest in the diabetes group.Significant difference for AGE was found in the epithelial cells of villi and crypt in duodenum(immunopositive area/total measuring area %:13.37 ± 3.51 vs 37.48 ± 8.43,P 0.05 for villi; 0.38 ± 0.12 vs 1.87 ± 0.53,P 0.05 for crypt) and for RAGE in neurons of all segments(e.g.,for jejunum:no staining neurons% 0 vs 0,mild 36.0 ± 5.2 vs 28.7 ± 3.5,moderate 53.2 ± 4.8 vs 55.8 ± 5.4,strong 10.7 ± 1.1 vs 15.4 ± 2.0,P 0.05).In the colon,RAGE was primarily found in neurons in the myenteric and submucosal plexus.It was stronger in the diabetes group than in the normal group(no staining neurons% 6.2 ± 0.2 vs 0.3 ± 0.04,mild 14.9 ± 2.1 vs 17.6 ± 1.5,moderate 53.1 ± 4.6 vs 44.7 ± 4.4,strong 25.6 ± 18 vs 43.6 ± 4.0,P 0.05).In the rectum,RAGE was primarily found in the mucosa epithelial cells.CONCLUSION:The AGE and RAGE expression was upregulated in the GI tract of GK diabetic rats and may contribute to GI dysfunction in type 2 diabetic patients.     

慢性肾衰竭大鼠肠道通透性及损伤的研究

Objective To observe the histopathologic injury of small intestine and intestinal permeability in chronic renal failure (CRF) rats. Methods Twenty male Sprague-Dawley rats were randomly assigned to CRF group (n=10) and control group (n=10). 5/6 nephrectomy was used to establish CRF rats, while sham operation for control. Blood biochemistry was regularly monitored until CRF model was successfully established. The model rats were fed with lactulose (L) and mannitol (M) through intragastric administration. Urine was collected after 6 hours, and the concentration of lactulose and mannitol in urine was measured using high pressure liquid chromatograph with refractive index detector (HPLC-RID), and the ratio of urinary excretion of L/M was calculated to evaluate intestinal permeability. Small intestinal mucosa were stained by hematoxylin-eosin (HE) and observed with light microscope (villus height, thickness of muscle layer and villus count), histological damage score was used to evaluate intestinal injury. Results The L/M ratio of CRF group was higher than that of control group (1.75±0.11 vs 1.20±0.06, P<0.01). The small intestinal mucosal villus height and thickness of muscle layer in CRF group were higher (P<0.01), and the number of villi was lower compared to control group (P<0.01). The score of histopathologic intestine damage of CRF group was higher than that of control group (1.00±0.71 vs 0, P<0.01). Conclusion The intestinal permeability of CRF rats is increased with varying degrees of intestinal damage.     

慢性肾衰竭大鼠肠道通透性及损伤的研究

Objective To observe the histopathologic injury of small intestine and intestinal permeability in chronic renal failure (CRF) rats. Methods Twenty male Sprague-Dawley rats were randomly assigned to CRF group (n=10) and control group (n=10). 5/6 nephrectomy was used to establish CRF rats, while sham operation for control. Blood biochemistry was regularly monitored until CRF model was successfully established. The model rats were fed with lactulose (L) and mannitol (M) through intragastric administration. Urine was collected after 6 hours, and the concentration of lactulose and mannitol in urine was measured using high pressure liquid chromatograph with refractive index detector (HPLC-RID), and the ratio of urinary excretion of L/M was calculated to evaluate intestinal permeability. Small intestinal mucosa were stained by hematoxylin-eosin (HE) and observed with light microscope (villus height, thickness of muscle layer and villus count), histological damage score was used to evaluate intestinal injury. Results The L/M ratio of CRF group was higher than that of control group (1.75±0.11 vs 1.20±0.06, P<0.01). The small intestinal mucosal villus height and thickness of muscle layer in CRF group were higher (P<0.01), and the number of villi was lower compared to control group (P<0.01). The score of histopathologic intestine damage of CRF group was higher than that of control group (1.00±0.71 vs 0, P<0.01). Conclusion The intestinal permeability of CRF rats is increased with varying degrees of intestinal damage.     

烫伤大鼠结肠动力基本功能单位细胞损害和内质网应激研究

Objective To observe expressions of glucose-regulated protein (GRF78) and caspase-12 in nervous system-interstitial cells of Cajal (ICC) in smooth muscle in colonic wall in rats with scald inju-ry, as well as their relevant ultrastructural changes, so as to probe the possible mechanisms of dynamic dam-age in murine colon after a scald injury. Methods Fifty healthy Sprague-Dawley rats were randomly di-vided into scald (n =40) and control (n = 10) groups. Rats in scald group were inflicted with 30% TBSA full-thickness scald, and received an intraperitoneally injection of Ringer lactate solution (50 mg/kg) for re-suscitation, while those in control group had similar treatment with the exception of scald. Rats in control group and scald group were sacrificed at 3, 6, 12, 24 post scald hour ( PSH, 10 rats at each time point) for collection of 4 cm of colonic tissue, 5 cm proximal to the cecum. A segment of colonic wall, 1 cm in length, was obtained from the middle of the harvested segment of colon, and it was fixed with 3% glutaraldebyde or 10% formaldehyde. The samples fixed with glutaraldehyde were used to observe uhrastructural alterations under transmission electron microscope, while that with formaldehyde were used to observe expressions of GRP78 and caspase-12 in colonic wall by immunohistochemical assay. Results The colonic smooth mus-cle cells of rats in control group showed regular arrangment, their organelles were abundant, nucleus central-ly located, euchromatin distributed evenly with more abundant mitochondrial cristae and less smooth endo-plasmic reticulum, neuronal organelles were abundant in intermuscular plexus, and ICC could be seen in the neighborhood of neurons. The colonic smooth muscle cells appeared in irregular and disordered manner in scald group, perinuclear space was widened, intercellular vacuoles were observed, mitochondria showed vac-uolation degeneration with dissolved and condensed cristae, rough endoplasmic reticula were dilated with par-tial dissolution, and perinuclear cytoplasm of ICC was obviously decreased. The expression of GRP78 was increased in scald group at 3, 6, 12 PSH (4.3±0.9, 6.0±0.7,4.8±1.1 score) as compared with that in control group ( 2.4±0.7 score, P<0.05 ). The expression of caspase-12 in scald group at 6, 12, 24 PSH was higher than that in control group (P<0.05). GRP78 was consistantly expressed in cytoplasm in con-trol group, while in scald group, it mainly appeared in mucosa, myenteric plexus, and stromal cells, but on-ly moderately or lightly expressed in smooth muscle cells. The expression of GRP78 was positive in scald group at 3, 6, 12 PSH, strongly positive at 6 PSH, and it was also expressed in cytoplasm in control group. The expression of caspase-12 in scald group was not obviously positive at 3 PSH, and weakly positive at 6, 24 PSH, but strongly positive at 12 PSH, while no expression was shown in control group. Conclusions Marked pathological changes are observed in enteric nervous system-interstitial cells of Cajal-smooth muscle in rats with severe scald injury. It may be related with cellular injuries induced by caspase-12 apoptotic path-ways through activated endoplasmic reticulum stress.     

烫伤大鼠结肠动力基本功能单位细胞损害和内质网应激研究

Objective To observe expressions of glucose-regulated protein (GRF78) and caspase-12 in nervous system-interstitial cells of Cajal (ICC) in smooth muscle in colonic wall in rats with scald inju-ry, as well as their relevant ultrastructural changes, so as to probe the possible mechanisms of dynamic dam-age in murine colon after a scald injury. Methods Fifty healthy Sprague-Dawley rats were randomly di-vided into scald (n =40) and control (n = 10) groups. Rats in scald group were inflicted with 30% TBSA full-thickness scald, and received an intraperitoneally injection of Ringer lactate solution (50 mg/kg) for re-suscitation, while those in control group had similar treatment with the exception of scald. Rats in control group and scald group were sacrificed at 3, 6, 12, 24 post scald hour ( PSH, 10 rats at each time point) for collection of 4 cm of colonic tissue, 5 cm proximal to the cecum. A segment of colonic wall, 1 cm in length, was obtained from the middle of the harvested segment of colon, and it was fixed with 3% glutaraldebyde or 10% formaldehyde. The samples fixed with glutaraldehyde were used to observe uhrastructural alterations under transmission electron microscope, while that with formaldehyde were used to observe expressions of GRP78 and caspase-12 in colonic wall by immunohistochemical assay. Results The colonic smooth mus-cle cells of rats in control group showed regular arrangment, their organelles were abundant, nucleus central-ly located, euchromatin distributed evenly with more abundant mitochondrial cristae and less smooth endo-plasmic reticulum, neuronal organelles were abundant in intermuscular plexus, and ICC could be seen in the neighborhood of neurons. The colonic smooth muscle cells appeared in irregular and disordered manner in scald group, perinuclear space was widened, intercellular vacuoles were observed, mitochondria showed vac-uolation degeneration with dissolved and condensed cristae, rough endoplasmic reticula were dilated with par-tial dissolution, and perinuclear cytoplasm of ICC was obviously decreased. The expression of GRP78 was increased in scald group at 3, 6, 12 PSH (4.3±0.9, 6.0±0.7,4.8±1.1 score) as compared with that in control group ( 2.4±0.7 score, P<0.05 ). The expression of caspase-12 in scald group at 6, 12, 24 PSH was higher than that in control group (P<0.05). GRP78 was consistantly expressed in cytoplasm in con-trol group, while in scald group, it mainly appeared in mucosa, myenteric plexus, and stromal cells, but on-ly moderately or lightly expressed in smooth muscle cells. The expression of GRP78 was positive in scald group at 3, 6, 12 PSH, strongly positive at 6 PSH, and it was also expressed in cytoplasm in control group. The expression of caspase-12 in scald group was not obviously positive at 3 PSH, and weakly positive at 6, 24 PSH, but strongly positive at 12 PSH, while no expression was shown in control group. Conclusions Marked pathological changes are observed in enteric nervous system-interstitial cells of Cajal-smooth muscle in rats with severe scald injury. It may be related with cellular injuries induced by caspase-12 apoptotic path-ways through activated endoplasmic reticulum stress.     

烫伤大鼠结肠动力基本功能单位细胞损害和内质网应激研究

Objective To observe expressions of glucose-regulated protein (GRF78) and caspase-12 in nervous system-interstitial cells of Cajal (ICC) in smooth muscle in colonic wall in rats with scald inju-ry, as well as their relevant ultrastructural changes, so as to probe the possible mechanisms of dynamic dam-age in murine colon after a scald injury. Methods Fifty healthy Sprague-Dawley rats were randomly di-vided into scald (n =40) and control (n = 10) groups. Rats in scald group were inflicted with 30% TBSA full-thickness scald, and received an intraperitoneally injection of Ringer lactate solution (50 mg/kg) for re-suscitation, while those in control group had similar treatment with the exception of scald. Rats in control group and scald group were sacrificed at 3, 6, 12, 24 post scald hour ( PSH, 10 rats at each time point) for collection of 4 cm of colonic tissue, 5 cm proximal to the cecum. A segment of colonic wall, 1 cm in length, was obtained from the middle of the harvested segment of colon, and it was fixed with 3% glutaraldebyde or 10% formaldehyde. The samples fixed with glutaraldehyde were used to observe uhrastructural alterations under transmission electron microscope, while that with formaldehyde were used to observe expressions of GRP78 and caspase-12 in colonic wall by immunohistochemical assay. Results The colonic smooth mus-cle cells of rats in control group showed regular arrangment, their organelles were abundant, nucleus central-ly located, euchromatin distributed evenly with more abundant mitochondrial cristae and less smooth endo-plasmic reticulum, neuronal organelles were abundant in intermuscular plexus, and ICC could be seen in the neighborhood of neurons. The colonic smooth muscle cells appeared in irregular and disordered manner in scald group, perinuclear space was widened, intercellular vacuoles were observed, mitochondria showed vac-uolation degeneration with dissolved and condensed cristae, rough endoplasmic reticula were dilated with par-tial dissolution, and perinuclear cytoplasm of ICC was obviously decreased. The expression of GRP78 was increased in scald group at 3, 6, 12 PSH (4.3±0.9, 6.0±0.7,4.8±1.1 score) as compared with that in control group ( 2.4±0.7 score, P<0.05 ). The expression of caspase-12 in scald group at 6, 12, 24 PSH was higher than that in control group (P<0.05). GRP78 was consistantly expressed in cytoplasm in con-trol group, while in scald group, it mainly appeared in mucosa, myenteric plexus, and stromal cells, but on-ly moderately or lightly expressed in smooth muscle cells. The expression of GRP78 was positive in scald group at 3, 6, 12 PSH, strongly positive at 6 PSH, and it was also expressed in cytoplasm in control group. The expression of caspase-12 in scald group was not obviously positive at 3 PSH, and weakly positive at 6, 24 PSH, but strongly positive at 12 PSH, while no expression was shown in control group. Conclusions Marked pathological changes are observed in enteric nervous system-interstitial cells of Cajal-smooth muscle in rats with severe scald injury. It may be related with cellular injuries induced by caspase-12 apoptotic path-ways through activated endoplasmic reticulum stress.     

烫伤大鼠结肠动力基本功能单位细胞损害和内质网应激研究

Objective To observe expressions of glucose-regulated protein (GRF78) and caspase-12 in nervous system-interstitial cells of Cajal (ICC) in smooth muscle in colonic wall in rats with scald inju-ry, as well as their relevant ultrastructural changes, so as to probe the possible mechanisms of dynamic dam-age in murine colon after a scald injury. Methods Fifty healthy Sprague-Dawley rats were randomly di-vided into scald (n =40) and control (n = 10) groups. Rats in scald group were inflicted with 30% TBSA full-thickness scald, and received an intraperitoneally injection of Ringer lactate solution (50 mg/kg) for re-suscitation, while those in control group had similar treatment with the exception of scald. Rats in control group and scald group were sacrificed at 3, 6, 12, 24 post scald hour ( PSH, 10 rats at each time point) for collection of 4 cm of colonic tissue, 5 cm proximal to the cecum. A segment of colonic wall, 1 cm in length, was obtained from the middle of the harvested segment of colon, and it was fixed with 3% glutaraldebyde or 10% formaldehyde. The samples fixed with glutaraldehyde were used to observe uhrastructural alterations under transmission electron microscope, while that with formaldehyde were used to observe expressions of GRP78 and caspase-12 in colonic wall by immunohistochemical assay. Results The colonic smooth mus-cle cells of rats in control group showed regular arrangment, their organelles were abundant, nucleus central-ly located, euchromatin distributed evenly with more abundant mitochondrial cristae and less smooth endo-plasmic reticulum, neuronal organelles were abundant in intermuscular plexus, and ICC could be seen in the neighborhood of neurons. The colonic smooth muscle cells appeared in irregular and disordered manner in scald group, perinuclear space was widened, intercellular vacuoles were observed, mitochondria showed vac-uolation degeneration with dissolved and condensed cristae, rough endoplasmic reticula were dilated with par-tial dissolution, and perinuclear cytoplasm of ICC was obviously decreased. The expression of GRP78 was increased in scald group at 3, 6, 12 PSH (4.3±0.9, 6.0±0.7,4.8±1.1 score) as compared with that in control group ( 2.4±0.7 score, P<0.05 ). The expression of caspase-12 in scald group at 6, 12, 24 PSH was higher than that in control group (P<0.05). GRP78 was consistantly expressed in cytoplasm in con-trol group, while in scald group, it mainly appeared in mucosa, myenteric plexus, and stromal cells, but on-ly moderately or lightly expressed in smooth muscle cells. The expression of GRP78 was positive in scald group at 3, 6, 12 PSH, strongly positive at 6 PSH, and it was also expressed in cytoplasm in control group. The expression of caspase-12 in scald group was not obviously positive at 3 PSH, and weakly positive at 6, 24 PSH, but strongly positive at 12 PSH, while no expression was shown in control group. Conclusions Marked pathological changes are observed in enteric nervous system-interstitial cells of Cajal-smooth muscle in rats with severe scald injury. It may be related with cellular injuries induced by caspase-12 apoptotic path-ways through activated endoplasmic reticulum stress.     

烫伤大鼠结肠动力基本功能单位细胞损害和内质网应激研究

Objective To observe expressions of glucose-regulated protein (GRF78) and caspase-12 in nervous system-interstitial cells of Cajal (ICC) in smooth muscle in colonic wall in rats with scald inju-ry, as well as their relevant ultrastructural changes, so as to probe the possible mechanisms of dynamic dam-age in murine colon after a scald injury. Methods Fifty healthy Sprague-Dawley rats were randomly di-vided into scald (n =40) and control (n = 10) groups. Rats in scald group were inflicted with 30% TBSA full-thickness scald, and received an intraperitoneally injection of Ringer lactate solution (50 mg/kg) for re-suscitation, while those in control group had similar treatment with the exception of scald. Rats in control group and scald group were sacrificed at 3, 6, 12, 24 post scald hour ( PSH, 10 rats at each time point) for collection of 4 cm of colonic tissue, 5 cm proximal to the cecum. A segment of colonic wall, 1 cm in length, was obtained from the middle of the harvested segment of colon, and it was fixed with 3% glutaraldebyde or 10% formaldehyde. The samples fixed with glutaraldehyde were used to observe uhrastructural alterations under transmission electron microscope, while that with formaldehyde were used to observe expressions of GRP78 and caspase-12 in colonic wall by immunohistochemical assay. Results The colonic smooth mus-cle cells of rats in control group showed regular arrangment, their organelles were abundant, nucleus central-ly located, euchromatin distributed evenly with more abundant mitochondrial cristae and less smooth endo-plasmic reticulum, neuronal organelles were abundant in intermuscular plexus, and ICC could be seen in the neighborhood of neurons. The colonic smooth muscle cells appeared in irregular and disordered manner in scald group, perinuclear space was widened, intercellular vacuoles were observed, mitochondria showed vac-uolation degeneration with dissolved and condensed cristae, rough endoplasmic reticula were dilated with par-tial dissolution, and perinuclear cytoplasm of ICC was obviously decreased. The expression of GRP78 was increased in scald group at 3, 6, 12 PSH (4.3±0.9, 6.0±0.7,4.8±1.1 score) as compared with that in control group ( 2.4±0.7 score, P<0.05 ). The expression of caspase-12 in scald group at 6, 12, 24 PSH was higher than that in control group (P<0.05). GRP78 was consistantly expressed in cytoplasm in con-trol group, while in scald group, it mainly appeared in mucosa, myenteric plexus, and stromal cells, but on-ly moderately or lightly expressed in smooth muscle cells. The expression of GRP78 was positive in scald group at 3, 6, 12 PSH, strongly positive at 6 PSH, and it was also expressed in cytoplasm in control group. The expression of caspase-12 in scald group was not obviously positive at 3 PSH, and weakly positive at 6, 24 PSH, but strongly positive at 12 PSH, while no expression was shown in control group. Conclusions Marked pathological changes are observed in enteric nervous system-interstitial cells of Cajal-smooth muscle in rats with severe scald injury. It may be related with cellular injuries induced by caspase-12 apoptotic path-ways through activated endoplasmic reticulum stress.     

烫伤大鼠结肠动力基本功能单位细胞损害和内质网应激研究

Objective To observe expressions of glucose-regulated protein (GRF78) and caspase-12 in nervous system-interstitial cells of Cajal (ICC) in smooth muscle in colonic wall in rats with scald inju-ry, as well as their relevant ultrastructural changes, so as to probe the possible mechanisms of dynamic dam-age in murine colon after a scald injury. Methods Fifty healthy Sprague-Dawley rats were randomly di-vided into scald (n =40) and control (n = 10) groups. Rats in scald group were inflicted with 30% TBSA full-thickness scald, and received an intraperitoneally injection of Ringer lactate solution (50 mg/kg) for re-suscitation, while those in control group had similar treatment with the exception of scald. Rats in control group and scald group were sacrificed at 3, 6, 12, 24 post scald hour ( PSH, 10 rats at each time point) for collection of 4 cm of colonic tissue, 5 cm proximal to the cecum. A segment of colonic wall, 1 cm in length, was obtained from the middle of the harvested segment of colon, and it was fixed with 3% glutaraldebyde or 10% formaldehyde. The samples fixed with glutaraldehyde were used to observe uhrastructural alterations under transmission electron microscope, while that with formaldehyde were used to observe expressions of GRP78 and caspase-12 in colonic wall by immunohistochemical assay. Results The colonic smooth mus-cle cells of rats in control group showed regular arrangment, their organelles were abundant, nucleus central-ly located, euchromatin distributed evenly with more abundant mitochondrial cristae and less smooth endo-plasmic reticulum, neuronal organelles were abundant in intermuscular plexus, and ICC could be seen in the neighborhood of neurons. The colonic smooth muscle cells appeared in irregular and disordered manner in scald group, perinuclear space was widened, intercellular vacuoles were observed, mitochondria showed vac-uolation degeneration with dissolved and condensed cristae, rough endoplasmic reticula were dilated with par-tial dissolution, and perinuclear cytoplasm of ICC was obviously decreased. The expression of GRP78 was increased in scald group at 3, 6, 12 PSH (4.3±0.9, 6.0±0.7,4.8±1.1 score) as compared with that in control group ( 2.4±0.7 score, P<0.05 ). The expression of caspase-12 in scald group at 6, 12, 24 PSH was higher than that in control group (P<0.05). GRP78 was consistantly expressed in cytoplasm in con-trol group, while in scald group, it mainly appeared in mucosa, myenteric plexus, and stromal cells, but on-ly moderately or lightly expressed in smooth muscle cells. The expression of GRP78 was positive in scald group at 3, 6, 12 PSH, strongly positive at 6 PSH, and it was also expressed in cytoplasm in control group. The expression of caspase-12 in scald group was not obviously positive at 3 PSH, and weakly positive at 6, 24 PSH, but strongly positive at 12 PSH, while no expression was shown in control group. Conclusions Marked pathological changes are observed in enteric nervous system-interstitial cells of Cajal-smooth muscle in rats with severe scald injury. It may be related with cellular injuries induced by caspase-12 apoptotic path-ways through activated endoplasmic reticulum stress.     

烫伤大鼠结肠动力基本功能单位细胞损害和内质网应激研究

Objective To observe expressions of glucose-regulated protein (GRF78) and caspase-12 in nervous system-interstitial cells of Cajal (ICC) in smooth muscle in colonic wall in rats with scald inju-ry, as well as their relevant ultrastructural changes, so as to probe the possible mechanisms of dynamic dam-age in murine colon after a scald injury. Methods Fifty healthy Sprague-Dawley rats were randomly di-vided into scald (n =40) and control (n = 10) groups. Rats in scald group were inflicted with 30% TBSA full-thickness scald, and received an intraperitoneally injection of Ringer lactate solution (50 mg/kg) for re-suscitation, while those in control group had similar treatment with the exception of scald. Rats in control group and scald group were sacrificed at 3, 6, 12, 24 post scald hour ( PSH, 10 rats at each time point) for collection of 4 cm of colonic tissue, 5 cm proximal to the cecum. A segment of colonic wall, 1 cm in length, was obtained from the middle of the harvested segment of colon, and it was fixed with 3% glutaraldebyde or 10% formaldehyde. The samples fixed with glutaraldehyde were used to observe uhrastructural alterations under transmission electron microscope, while that with formaldehyde were used to observe expressions of GRP78 and caspase-12 in colonic wall by immunohistochemical assay. Results The colonic smooth mus-cle cells of rats in control group showed regular arrangment, their organelles were abundant, nucleus central-ly located, euchromatin distributed evenly with more abundant mitochondrial cristae and less smooth endo-plasmic reticulum, neuronal organelles were abundant in intermuscular plexus, and ICC could be seen in the neighborhood of neurons. The colonic smooth muscle cells appeared in irregular and disordered manner in scald group, perinuclear space was widened, intercellular vacuoles were observed, mitochondria showed vac-uolation degeneration with dissolved and condensed cristae, rough endoplasmic reticula were dilated with par-tial dissolution, and perinuclear cytoplasm of ICC was obviously decreased. The expression of GRP78 was increased in scald group at 3, 6, 12 PSH (4.3±0.9, 6.0±0.7,4.8±1.1 score) as compared with that in control group ( 2.4±0.7 score, P<0.05 ). The expression of caspase-12 in scald group at 6, 12, 24 PSH was higher than that in control group (P<0.05). GRP78 was consistantly expressed in cytoplasm in con-trol group, while in scald group, it mainly appeared in mucosa, myenteric plexus, and stromal cells, but on-ly moderately or lightly expressed in smooth muscle cells. The expression of GRP78 was positive in scald group at 3, 6, 12 PSH, strongly positive at 6 PSH, and it was also expressed in cytoplasm in control group. The expression of caspase-12 in scald group was not obviously positive at 3 PSH, and weakly positive at 6, 24 PSH, but strongly positive at 12 PSH, while no expression was shown in control group. Conclusions Marked pathological changes are observed in enteric nervous system-interstitial cells of Cajal-smooth muscle in rats with severe scald injury. It may be related with cellular injuries induced by caspase-12 apoptotic path-ways through activated endoplasmic reticulum stress.     

门静脉动脉化对扩大肝-胆切除术后肝脏储备功能的影响

目的 观察慢性、梗阻性黄疸小型猪肝-胆切除术联合限流性部分门静脉动脉化(PPVA)术后肝脏储备功能的动态变化.方法 利用梗阻性黄疸小型猪模型,模拟进行联合半肝切除的肝门部胆管癌扩大根治性手术.实验分组:无黄疸对照组(A组,n=4)、门静脉动脉化组(B组,n=4)及非门静脉动脉化组(C组,n=4).对照观察根治术中应用限流性PPVA在术后30 d内的吲哚菁绿15 min滞留率(ICG15),从而判断肝脏储备功能的动态变化.结果 术前B、C组高于A组[(0.66±0.07)%、(0.64±0.09)%比(0.09±0.01)%,P＜0.01],术后第1天B组低于C高于A组[(0.59±0.11)%比(0.82±0.09)%、(0.18±0.04)%,P＜0.05、P＜0.01],术后第7天B组高于A组低于C组[(0.34±0.09)比(0.17±0.04)%、(0.69±0.11)%,P均＜0.05].术后第30天B组低于C组、与A组差异无统计学意义[(0.12±0.03)%比(0.22±0.03)%、(0.09±0.003)%,P＜0.01、P＞0.05].B组术后第7天低于术前[(0.34±0.09)%比(0.66±0.07)%,P＜0.01].结论 限流性PPVA可促进慢性梗阻性黄疸小型猪肝-胆切除术后残肝储备功能的恢复.

Abstract：

Objective To investigate the change of hepatic functional reserve (HFR) after flowcontrolled partial portal vein arterialization (PPVA) in hepato-biliary resection (HBR) in miniature pigs with obstructive jaundice. Methods Eight miniature-pig models with chronic gradually obstructive jaundice were divided into 2 groups with 4 pigs each: PPVA group (group B,n =4), non-PPVA group (group C, n = 4), and another 4 pigs without chronic gradually obstructive jaundice served as control group ( group A, n = 4). Approaches of EHBR with or without PPVA were done, then the effects of flow-controlled PPVA on HFR of remnant liver were studied by detecting indocyanine-green retention at 15 min ( ICG15 ) in 30 days post-operation. Results ICG15 in groups B and C was significantly higher than in group A pre-operation[(0.66±0.07)%, (0.64±0.09)% vs (0.09±0.01)%,P＜0.01]. ICG15 in group B was significantly lower than that in group C, and higher than in group A at the first day post-operation[(0. 59 ±0.11)% vs (0.82±0.09)%, (0.59±0.11)% vs (0. 18±0.04)%,P＜0. 05,P＜0. 01]. ICG15 in group B was significantly lower than in group C, and higher than in group A at 7th day post-operation [(0. 34±0.09)% vs (0.69 ±0. 11)%, (0.34±0.09)% vs (0. 17 ±0.04)% ,both P＜0.05]. ICG15 in group B was significantly lower than in group C, but showed no significant difference from group A at 30th day post-operation[(0.12 ±0.03)% vs (0.22 ±0.03)%, (0.12 ±0.03)% vs (0.09 ± 0. 003)% ,P ＜0. 01 ,P ＞ 0. 05]. ICG15 in group B on the 7th day post-operation was significantly lower than that pre-operation[(0. 34 ± 0. 09 ) % vs (0. 66 ± 0. 07 ) %, P ＜ 0. 01]. Conclusion Flow-controlled PPVA in HBR is beneficial to recovery of HFR on miniature pigs with obstructive jaundice.     

低分子右旋糖酐铁和蔗糖铁对慢性肾衰竭大鼠氧化应激的影响

目的 评价小剂量反复多次低分子右旋糖酐铁和蔗糖铁静脉用药后对慢性肾衰竭大鼠氧化应激的影响。 方法 以5/6肾大部切除术建立慢性肾衰竭大鼠模型。右肾切除术后第4周,将实验大鼠分为4组：低分子右旋糖酐铁（糖酐铁）组、蔗糖铁组、对照组、假手术组。观察6周,检测各组大鼠体内氧化应激、铁代谢等指标。 结果 糖酐铁组和蔗糖铁组大鼠血红蛋白明显高于对照组（P < 0.05）,而两铁剂组间差异无统计学意义。对照组大鼠的血清铁、血清铁蛋白、转铁蛋白饱和度显著低于假手术组（P < 0.05）;两铁剂组大鼠上述指标均显著高于对照组（P < 0.05）,而两铁剂组间差异无统计学意义。糖酐铁组和蔗糖铁组血浆晚期氧化蛋白产物（AOPP）显著高于对照组[（127.84±21.19） μmol/L、（134.21±29.38） μmol/L比 （81.83±19.93） μmol/L,P < 0.05],而两铁剂组间差异无统计学意义。两铁剂组大鼠血浆丙二醛（MDA）高于对照组,而蔗糖铁组高于糖酐铁组[（6.06±0.73） nmol/L比（4.99±0.80） nmol/L, P < 0.05]。糖酐铁组、蔗糖铁组和对照组大鼠血清超氧化物歧化酶（SOD）和总抗氧化能力（TAOC）差异无统计学意义。模型组大鼠血浆谷胱甘肽过氧化物酶（GSH-Px）水平显著低于假手术组（P < 0.05）,而蔗糖铁组显著低于糖酐铁组和对照组[（2123.11±74.78） nmol&#8226;ml-1&#8226;min-1比（2352.84±163.90） nmol&#8226;ml-1&#8226;min-1、（2310.23±125.99） nmol&#8226;ml-1&#8226;min-1,P < 0.05]。 结论 静脉补铁可部分纠正5/6肾大部切除肾衰竭大鼠的贫血,改善铁代谢指标。反复静脉小剂量补铁对慢性肾衰竭大鼠氧化应激状态有不良影响,而低分子右旋糖酐铁的不良影响低于蔗糖铁。     

高压氧治疗小鼠急性胰腺炎

目的 观察高压氧(HBO)在小鼠急性胰腺炎中的作用。方法 建立胰腺炎小鼠模型,随机分为高压氧治疗组和对照组。高压氧治疗组中,小鼠模型建立6h后给予100％氧,2.5个大气压治疗90 min,之后每12h给予治疗1次。第7天处死存活的小鼠。进行胰腺炎的严重程度进行分级肉眼及镜下分析,计算肺的湿、干重来评价肺水肿。比较两组间的差异。结果 治疗组中肉眼及显微镜下的胰腺炎的严重程度评分8.2±0.8及9.5±0.3,明显低于对照组10.6±0.6及11.2±0.3(P＜0.05)。治疗组胰腺坏死表现也明显较对照组减少,分别为(41±5)％及(55±5)％(P＜0.01)。两组的肺水肿差异无统计学意义(P＞0.05)。治疗组7d存活率明显高于对照组,分别为(39±3)％和(26±1)％(P＜0.05)。结论 高压氧治疗可以降低胰腺炎的坏死程度,提高重症急性胰腺炎的生存率。     

骨髓间充质细胞和单个核细胞移植对糖尿病小鼠胰岛功能的影响

目的 比较骨髓间充质细胞移植和单个核细胞移植对糖尿病小鼠胰岛功能影响的差异.方法 建立糖尿病小鼠模型并分成3组:对照组(n=14)通过尾静脉注射磷酸盐缓冲液(PBS);单个核细胞组(n=14)通过尾静脉移植骨髓单个核细胞;间充质细胞组(n=14)通过尾静脉移植骨髓间充质细胞.观察移植后1周(n=6)和移植后6周(n=8),各组小鼠血糖的变化、胰岛数量、胰腺组织形态学特征及相关标记物的表达.结果 移植后1周,间充质细胞组小鼠血糖出现显著下降(16.6±1.6)mmol/L,与对照组(26.3±0.5)mmol/L和单个核细胞移植组(24.4±1.3)mmol/L比较差异有统计学意义(P＜0.05),并一直维持到移植后第6周,血糖下降到(16.5±1.5)mmol/L,与对照组(27.7±0.1)mmol/L比较差异有统计学意义(P＜0.05);移植后1周,间充质细胞组小鼠胰岛数目(21.2±1. 1)和胰岛β细胞数目(415.9±25.4)显著增加,与对照组(11.2±1.3)/(65.9±7.1)和单个核细胞组(12.2±1.3)/(64.1±6.5)比较差异均有统计学意义(P均＜0.05).单个核细胞组和间充质细胞组小鼠胰岛中均发现BrdU(+)Insulin(+)细胞和BrdU(+)Insulin(-)细胞.结论 骨髓间充质细胞移植改善糖尿病小鼠胰岛功能的效果优于骨髓单个核细胞移植.移植后胰岛的再生既来源于胰岛β细胞的增殖,也可能来源于胰岛干细胞的分化.

Abstract：

Objective To compare the different effects of bone marrow mononuclear cells vs mesenchymal cells transplantation on islets function of diabetic mice. Methods Mouse diabetic models were created by multiply peritoneal injection of low-dose streptozotocin (STZ) and divided into three groups:control group ( n = 14) , bone marrow mononuclear cells group ( n = 14) , and bone marrow mesenchymal cells group (n = 14). Blood glucose was measured weekly after transplantation by glucometer. Histochem istry and immunofluorescence were performed to characterize pancreatic histology, morphology and markers expressed in receipt pancreas. Results Compared with control group and bone marrow mesenchymal cells group, blood glucose levels in bone marrow mesenchymal cells group were significantly reduced at first week after transplantation[( 16. 6 ± 1.6 ) vs ( 26. 3 ± 0. 5 ) / ( 24. 4 ± 1.3 ) mmol/L, P ＜ 0. 05]and sustained to reduce at 6th week after transplantation[( 16. 5 ± 1.5 ) vs ( 27.7 ± 0. 1 ) mmol/L in control group,P＜0. 05]. One week after transplantation, the islets number in bone marrow mesenchymal cells group was larger than in control group ( 21.2 ± 1. 1vs 11.2 ± 1.3, P ＜ 0. 05 ) and bone marrow mononuclear cells group ( 21.2 ± 1. 1vs 12. 2 ± 1.3 ,P ＜0. 05 ). One weeks after transplantation, the beta cell number in bone marrow mesenchymal cells group was larger than in control group (415.9 ± 25.4 vs 65.9 ±7. 1,P＜0.05) and bone marrow mononuclear cells group (415.9 ±25.4 vs 64. 1 ±6.5,P＜0.05). In bone marrow mononuclear cells and bone marrow mesenchymal cells groups, there were several BrdU ( + )Insulin( - ) cells and BrdU( + )Insulin( - ) cells in the islets. Conclusion The effect of bone marrow mesenchymal cells transplantation to improve diabetic islet function is more satisfactory than bone marrow mononuclear cells transplantation. Bone marrow mesenchymal cells transplantation can initiate pancreatic islets β cells regeneration by both proliferation of β cells and differentiation of pancreatic stem cells.     

电刺激迷走神经对脓毒症大鼠凝血功能的影响

目的 观察电刺激迷走神经对脓毒症大鼠凝血功能的影响.方法 采用经左侧股静脉注射脂多糖(LPS,10mg/kg)复制脓毒症模型.将雄性SD大鼠96只随机分成4组:生理盐水组(SHAM组)、脓毒症组(LPS组)、迷走神经切断组(VGX组)、电刺激迷走神经组(VNS组).将左侧迷走神经远端与双铂电极连接,于模型制备成功即刻行电刺激(5 V,2 ms,1 Hz)20 min.于注射脂多糖前(0 h),注入后2、4、6 h各个时间点取6只动物,经腹主动脉取血查血浆凝血酶原时间(PT)、活化部分凝血酶原时间(aPTT)、血浆凝血酶时间(TT)、血浆纤维蛋白原(Fbg)和肿瘤坏死因子-α(TNF-α)水平.结果 在予以LPS 2 h后,LPS组(316.34±23.96)ng/L和VGX组(325.77±39.77)ng/L血浆TNF-α水平较VNS组(252.72±30.36)ng/L升高(P＜0.05);6 h时,LPS组(10.68±0.66)s和VGX组(10.72±0.57)s与VNS组(9.67±1.04)s比较PT时间延长(P＜0.05);2 h时,LPS组(23.4 ±0.5)s和VGX组(23.9±0.5)s与VNS组(18.4±1.1)s比较aPTT时间延长(P＜0.05);4 h时,LPS组(32.0±1.0)s和VGX组(32.7±0.8)s与VNS组(28.7±1.9)s比较,TT时间延长(P＜0.05);4 h时,LPS组(1.909±0.224)g/L和VGX组(1.822±0.329)g/L与VNS组(2.376±0.138)g/L比较,Flg浓度降低(P＜0.05).结论 电刺激迷走神经不仅可以有效地抑制脓毒症大鼠血浆TNF-α水平,抑制炎症反应,而且还可以改善脓毒症大鼠的凝血功能紊乱.     

WWOX表达对胆管癌QBC939细胞凋亡的影响及其机制

目的 探讨含有WW结构域的氧化还原酶基因(WWOX)表达对胆管癌QBC939细胞凋亡的影响及其作用机制.方法 用脂质体转染法将WWOX重组真核表达质粒转染QBC939细胞;采用荧光定量逆转录－聚合酶链反应(RT-PCR)和Westem blot法鉴定WWOX在QBC939细胞中的表达;流式细胞仪(FCM)法检测转染前后各细胞凋亡率的变化;JC-l染色法检测细胞线粒体膜电位(△Ψm)变化;荧光定量RT-PCR和Western blot法检测胆管癌细胞bcl-2表达的变化;将未转染和转染空质粒的细胞作为对照组接种到裸鼠皮下以检测荷瘤,TUNEL方法原位检测移植瘤的凋亡.结果 建立了稳定表达WWOX基因的QBC939/WWOX细胞株,mRNA及蛋白表达明显增加.FCM显示QBC939/WWOX组的细胞凋亡率明显增高[(1.24±0.35)％比(1.73±0.48)％比(21.40±2.35)％,P＜O.01],JC-l显示转染组的线粒体膜电位下降[(4.27±0.64)％比(4.96±0.52)％比(28.60±3.94)％,P＜O.01],bcl-2 mRNA及蛋白的表达均显著降低(P＜0.05).转染组的皮下肿瘤较对照组生长速度明显减慢(P＜0.05),TUNEL实验证实转染组的皮下肿瘤凋亡指数为(13.6±1.5)％,较对照组明显增高,差异有统计学意义(P＜0.O1).结论 WWOX基因能促进胆管癌细胞的凋亡,其机制可能与下调bcl-2的表达,激活线粒体凋亡通路有关.     

线粒体ATP敏感性钾通道阻断剂对在体大鼠肺缺血后处理的作用及其机制

目的 探讨缺血后处理(IPO)对大鼠在体肺缺血-再灌注损伤(I/R)的保护作用及线粒体ATP敏感性钾通道(mitoKATP)在缺血后处理效应中的作用.方法 将Wistar大鼠35只随机分为5组:假手术组(Sham组)、缺血再灌注损伤组(I/R组)、缺血后处理组(IPO组)、缺血再灌注损伤+5-羟基葵酸盐组(I/R+5-HD组)、缺血后处理+5-羟基葵酸盐组(IPO+5-HD组).观察各组肺组织中丙二醛(MDA)含量、超氧化物歧化酶(SOD)活性、湿/干比值(W/D)以及病理形态学改变.结果 I/R组与Sham组比较MDA含量增加[(5.07±1.60)nmol/mg prot比(1.43±0.41)nmol/mgprot,P＜0.01],SOD活性减低[(12.38±2.24)U/mg prot比(45.51±5.42)U/mg prot,P＜0.01],W/D比值增高(5.45±0.82比3.05±0.47,P＜0.01),肺组织形态及超微结构明显受损;IPO+5-HD组与IPO组比较MDA含量增加[(3.74±0.71)nmol/mg prot比(2.60±0.43)nmol/mg prot,P＜0.01],SOD活性减低[(22.91±2.71)U/mg prot比(28.74±2.03)U/mg prot,P＜0.01],W/D比值增高(4.64±0.79比3.89±0.60,P＜0.01),肺组织形态及超微结构明显受损;IPO组与I/R组比较,肺组织MDA含量减少[(2.60±0.43)nmol/mg prot比(5.07±1.60)nmol/mg prot,P＜0.01],SOD活性增高[(28.74±2.03)U/mg prot比(12.38±2.24)U/mg prot,P＜0.01],W/D比值减低(3.89±0.60比5.45±0.82,P＜0.01),肺组织病理形态学改变轻于I/R组;I/R+5-HD组与I/R组比较,肺组织MDA含量[(5.14±1.30)mol/mg prot比(5.07±1.60)mol/mg prot,P＞0.05)、SOD活性[(11.65±1.82)U/mg prot比(12.38±2.24)U/mg prot,P＞0.05]、W/D比变化(5.54±0.61比5.45±0.82),差异无统计学意义(P＞0.05),肺组织病理形态学改变无明显差异.IPO+5-HD组的各项指标介于IPO组和I/R组之间.结论 缺血后处理能减轻大鼠在体肺缺血再灌注损伤,mitoKATP参与了肺缺血后处理效应.

Abstract：

Objective To investigate the protective effect of ischemic postconditioning (IPO) on lung ischemic reperfusion (L/R) in rats in vivo and the mechanism of mitochondrial ATP-sensitive potassium channel (mitoKATP) blocker in the ischemic postconditioning. Methods Thirty five Wistar rats were randomly divided into 5 groups: sham group, I/R group, ischemic postconditioning (IPO) group, I/R +5-hydroxydecanoate (I/R + 5-HD) group, IPO + 5-HD group. The concentration of malondialdehyde (MDA) and activity of superoide dismutase (SOD) were determined in the lung homogenate, wet to dry weight ratio (W/D) was measured and pathological changes were also observed. Results The levels of MDA[(5.07±1.60) vs (1.43 ±0.41) nmol/mg prot,P＜0. 01]and W/D (5.45 ±0.82 vs 3.05 ±0. 47,P ＜0. 01 ) were increased significantly in I/R group as compared with sham group, while the activity of SOD[( 12. 38 ±2. 24) vs (45.51 ±5.42) U/mg prot,P ＜0. 01]was decreased, and the injury of lung tissues was significantly aggravated in IPO + 5-HD group as compared with IPO group[MDA: (3.74 ±0. 71 ) nmol/mg prot vs (2. 60 ± 0. 43 ) nmol/mg prot , P ＜ 0. 01]; W/D: 4. 64 ± 0. 79 vs 3. 89 ± 0. 60,P＜0.01; SOD:[(22.91 ±2.71) U/mg prot vs (28.74±2.03) U/mg prot,P＜0. 01]. The levels of MDA[(2.60±0.43) vs (5.07 ±1.60) nmol/mg prot,P＜0. 01]and W/D (3.89 ±0.60 vs 5.45 ±0. 82,P ＜0. 01 ) were decreased significantly in IPO group as compared with I/R group, the activity of SOD[(28.74±2.03) vs (12.38 ±2.24) U/mg prot,P＜0. 01]increased and lung tissue histological damage attenuated. The difference in MDA[(5.14 ± 1.30) vs (5.07 ± 1.60) nmol/mg prot, P ＞ 0. 05],W/D (5.54±0.61 vs5.45 ±0.82,P＞0.05) and SOD[(11.65 ±1.82) vs (12.38 ±2.24) U/mgprot,P ＞ 0. 05]levels had no statistical significance between I/R + 5-HD group and I/R group, and the injury of lung tissues had no significant difference too. Each index in IPO + 5-HD group was between IPO and I/R groups. Conclusion Ischemic postconditioning can attenuate the lung I/R injury, and mitoKATP plays a vital role in the protective procession of ischemic postconditioning on lung ischemic reperfusion.     

骨髓间充质干细胞对大鼠慢性胰腺炎炎性因子的影响

目的 观察骨髓间充质干细胞(BMSCs)对大鼠慢性胰腺炎(CP)炎性因子的影响。方法 将80只SD大鼠随机分为空白组(20只,注射无菌生理盐水),模型组[20只,尾静脉注射二丁基二氯化物(DBTC)制作大鼠CP模型],假治疗组(20只,尾静脉注射DBTC制作大鼠CP模型后,输入和BMSCs等量的无菌生理盐水)和治疗组(20只,于CP模型制作成功后尾静脉注射体外培养的同种异体BMSCs)。80 d后采用酶联免疫吸附试验(ELISA)法检测各组大鼠胰腺中白细胞介素(IL)-1、IL-6、IL-8、IL-10、肿瘤坏死因子(TNF)-d、转化生长因子(TGF)-β水平。结果 治疗组中IL-1 (652.326±36.424) ng/L,IL-6(8.347±1.094) ng/L,IL-8( 352.487±69.340) ng/L,rGF-β(0.020±0.006) μg/L,均低于假治疗组与模型组(P＜0.05),IL-10(603.799±89.374) ng/L,TNF-α( 507.450±90.130)μg/L则高于假治疗组和模型组(P＜0.05)。模型组和假治疗组之间IL-1、IL-6、IL-8、IL-10、TNF-α、TGF-β的表达水平差异无统计学意义(P＞0.05)。结论 同种异体BMSCs的输入可以降低CP中促炎因子的水平,提高抗炎因子的浓度,有助于减轻CP的炎症反应,减缓甚至阻止CP的发展。     

钙预处理对未成熟心肌的保护作用

目的 观察钙预处理对未成熟心肌的影响.方法 采用Langendorff离体灌注模型,分为3组,缺血再灌组(I/R):离体心脏灌注10 win、工作心15 min后停灌45 min恢复灌注15 min,转为工作心模型30 min;心脏缺血预处理组(IPC):离体灌注10 min转为工作心15 min,反复2次缺血5min/再灌5min,停灌45min后恢复灌注15min,转为工作心模型30min;钙预处理组(CP):离体心脏灌注10 min、工作心15 min后,反复3次45 s无钙KH液灌流/5 min KH液灌流,停灌45 min后恢复灌注15 min,转为工作心模型30 min.以血流动力学指标、生化指标和心肌超微结构作为观察指标.结果 IPC与CP组比较,血流动力学指标、生化指标和心肌超微结构等方面均无明显差异;CP、IPC与I/R组比较,左心室功能恢复、三磷酸腺苷含量(ATP)(11.53±1.85、13.40±1.96比4.27±0.83,P＜0.01)、超氧化物歧化酶(SOD)活性(230.47±11.72、236.28±12.69比124.17±6.20,P＜0.01)、心肌线粒体Ca2+ATP酶活性(17.86±1.39、16.38±1.27比6.78 ±0.64,P＜0.01)和心肌线粒体合成ATP的能力(104.29±9.60、102.43±9.53比50.83±4.75,P＜0.01)明显增强,在心肌含水量(75.32±1.25、73.29±1.26比84.23±2.03,P＜0.01)、丙二醛含量(1.32±0.12、1.23±0.11比2.61±0.37,P＜0.01)、肌酸激酶(53.17±5.32、57.47±5.62比123.65±9.63,P＜0.01)和乳酸脱氢酶漏出率(32.16±3.23、34.48±3.43比85.43±5.93,P＜0.01)、心肌细胞内(2.54 ±0.32、2.17±0.22比4.48±0.74,P＜0.01)和心肌线粒体Ca2+含量(35.91±4.01、36.85±3.97比68.29±6.90,P＜0.01)明显减少;CP、IPC组心肌超微结构损伤较I/R组明显减轻.结论 钙预处理对未成熟心肌具有明显保护作用

Abstract：

Objective To investigate the protective effects of Ca2+ preconditioning on isolated immature myocardium.Methods Isolated working rabbit heart model was used,and 18 rabbits were randomly divided into 3 groups:ischemic/reperfusion (I/R) group receiving 45 min ischemia followed by 45 min reperfusion;myocardial ischemic preconditioning (IPC) group receiving 5 min ischemia and 5 min reperfusion 2 times before 45 min ischemia followed by 45 min reperfusion;Ca2 + preconditioning (CP)group receiving no-Ca2 + preconditioning before 45 min ischemia followed by 45 min reperfusion.The hemodynamics,biochemistry and myocardial ultrastructure were tested.Results The hemodynamics,biochemistry and myocardial ultrastructure had no significant diferrence between CP group and IPC group.As compared with I/R group,in CP and IPC groups,the left ventricular function recovery,adenosine triphosphate content (ATP) (11.53 ± 1.85,13.40 ± 1.96 vs 4.27 ±0.83,P＜0.01),superoxide dismutase (SOD)activity (230.47± 11.72,236.28 ± 12.69 vs 124.17 ±6.20,P＜0.01),Ca2+-ATPase activity of mitothondia ( 104.29 ± 9.60,102.43 ± 9.53 vs 50.83 ± 4.75,P＜0.01 ) and synthesized ATP activity of mitochondria ( 104.29 ±9.60,102.43 ±9.53 vs 50.83 ±4.75 ,P ＜0.01 ) were improved,and myocardial water content ( 75.32 ± 1.25,73.29 ± 1.26 vs 84.23 ± 2.03 ,P＜0.01 ),malondialdehyde content ( 1.32 ± 0.12,1.23 ± 0.11 vs 2.61 ± 0.37 ,P＜0.01 ),the dehydrogenase (32.16 ± 3.23,34.48 ± 3.43 vs 85.43 ± 5.93,P ＜0.01 ) and creatine kinase leakage (53.17 ±5.32,57.47±5.62 vs 123.65 ±9.63 ,P ＜0.01 ),myocardial cell Ca2+ content (2.54 ±0.32,2.17 ±0.22 vs 4.48 ±0.74 ,P ＜0.01 ) and mitochondrial Ca2+ content(35.91 ±4.01,36.85 ±3.97 vs 68.29 ±6.90,P ＜0.01 ) were reduced.The ultra.structure injury was milder in CP group and ICP group than in I/R group.Conclusion CP has signifcantly protective effects on immature myocardium.