Hyaluronan metabolism in rat tail skin following blockage of the lymphatic circulation

This study was undertaken to explore the effects of lymphatic blockage on the metabolism of hyaluronan in the skin. In initial experiments, [3H] hyaluronan was injected subcutaneously into the tail skin of rats that either had no surgical intervention (control) or into those that had their lymphatic drainage blocked two hours earlier (acute lymphedema) or after the lymphatics had been blocked for three months (chronic lymphedema). The removal of tritiated hyaluronan from the injection sites was determined by the appearance of [3H] in the plasma. The results showed that the clearance of injected hyaluronan was delayed in rats with lymphatic blockage. The half- life of injected hyaluronan in the controls was approximately 70-75 hr, compared with approximately 105-110 hr in the lymph blocking rats. The levels of radioactivity in the plasma from rats with both acute and chronically blocked lymphatics were lower than that of control rats during the entire follow up period. In addition, biochemical analysis revealed that there was a significant increased amount of hyaluronan in the tail skin three months after lymphatic blocking. These results suggest that lymph absorption is an important factor in the transport of hyaluronan from the interstitium. Blockage of regional draining lymphatics likely impairs the catabolism of hyaluronan, which stagnates in skin tissue.     

Significant changes in intestinal lymphatic system and immune response elicited by Peyer's patch excision in adult rats

Abstract The effect of deprivation of Peyer's patches (PP) on transport of lymphocytes through intestinal lymph and intestinal mucosal immune responses was investigated in rats. All visible PP in the rat small intestine were excised in order to examine the roles of PP in the intestinal lymphatic system and mucosal immune responses of the intestine. Two weeks after the experimental excision of PP, lymphocyte transport in intestinal lymph was significantly decreased in PP-excised rats without significant changes in lymphocyte subsets as compared with sham operated control rats. Lymphocyte subsets as determined morphometrically in the intestinal mucosa showed no significant alteration in PP-excised rats. There was a significant decrease in the number of immunoglobulin A (IgA) containing cells in the intestinal mucosa of PP-excised rats, while IgM and IgG containing cells showed no statistically significant changes in number. Conversely, the macrophages in the intestinal mucosa increased in number, suggesting the enhanced accessory functions of these macrophages. Antigen-specific immune response was further studied in PP-excised rats using intraduodenal priming and challenge with cholera toxin (CT). Both the determinations of cells producing antigen-specific antibody in the intestinal mucosa using anti-CT antibody and those of cells secreting anti-CT Ig in the intestinal lymph by enzyme-linked immunospot (ELISPOT) assay showed a significant reduction of CT-specific antibody production in PP-excised rats compared with controls. Peyer's patches appear to have an important role in lymphocyte transportation through intestinal lymph and also in mucosal immune responses.     

静脉输入休克肠淋巴液对正常大鼠红细胞流变性的作用

目的 观察静脉输入休克肠淋巴液对正常大鼠红细胞流变性的作用.方法 复制失血性休克大鼠模型后,引流低血压1～3h的肠淋巴液.将引流的休克肠淋巴液离心去细胞后的淋浆以等量生理盐水稀释后,经股静脉回输至正常大鼠(2 ml/kg),时间为30 min;另一组大鼠输入等量生理盐水作为对照组.输液结束后2.5h,经腹主动脉取血,检测红细胞电泳能力、红细胞沉降率(ESR)、红细胞变形性与聚集性等反映红细胞流变性的指标.结果 静脉输入休克肠淋巴液降低了正常大鼠红细胞的电泳率与迁移率,延长了红细胞电泳时间,但对红细胞变形指数与聚集指数、红细胞沉降指标无明显影响.结论 休克肠淋巴液是引起红细胞流变性异常的重要因素之一.     

Intravenous infusion of mesenteric lymph from severe intraperitoneal infection rats causes lung injury in healthy rats

AIM:To investigate whether mesenteric lymph from rats with severe intraperitoneal infection(SII)induces lung injury in healthy rats.METHODS:Twenty adult male specific pathogen-free Wistar rats were divided into two groups.Animals in the SII group received intraperitoneal injection of Escherichia coli(E.coli)at a dose of 0.3 mL/100 g.Control rats underwent the same procedure,but were injected with normal saline rather than E.coli.We ligated and drained the mesenteric lymphatic vessels and collected the mesenteric lymph.Mesenteric lymph collected from SII or control rats was infused intravenously into male healthy rats at a rate of 1 mL/h for 4 h.At the end of the infusion,all rats were sacrificed.Lungs were removed and examined histologically,and wet-to-dry weight(W/D)ratio and myeloperoxidase(MPO)activity were determined.Enzyme-linked immunosorbent assay(ELISA)was performed to determine the levels of the proinflammatory cytokines tumor necrosis factor(TNF)-αand interleukin(IL)-6.We performed Western blot to investigate the activation of Toll-like receptor(TLR)-4,and nuclear factor(NF)-κB p65.RESULTS:Compared with the control infusion group,there were obvious pathological changes in the SII group.The W/D ratio was significantly increased in the SII compared to control infusion group(5.86±0.06vs 5.37±0.06,P<0.01).MPO activity significantly increased in the SII infusion rats with a mean level of0.86±0.02 U/g compared to 0.18±0.05 U/g in the control group(P<0.01).The concentrations of TNF-αand IL-6 were significantly increased in the SII infusion group.The concentration of TNF-αwas significantly increased in the SII infusion rats compared to control infusion rats(2104.46±245.91 vs 1475.13±137.82pg/mL,P<0.01).The concentration of IL-6 was significantly increased in the SII infusion rats with a mean level of 50.56±2.85 pg/mL compared to 43.29±2.02 pg/mL(P<0.01).The expression levels of TLR-4(7496.68±376.43 vs 4589.02±233.16,P<0.01)and NF-κB(8722.19±323.96 vs 6498.91±338.76,P<0.01)were significantly increased in the SII infusion group compared to the control infusion group.The infusion of SII lymph,but not control lymph,caused lung injury.CONCLUSION:The results indicate that SII lymph is sufficient to induce acute lung injury.     

Flow in lymphatic networks: interaction between hepatic and intestinal lymph vessels

OBJECTIVE: Lymph from both the liver and intestine flows into the cisterna chyli. We hypothesized that increasing liver lymph flow would increase cisterna chyli pressure and, thereby, decrease intestinal lymph flow, potentiating intestinal edema formation. METHODS: Anesthetized dogs were instrumented to measure and manipulate portal vein pressure and cisterna chyli pressure. The effects of directly increasing portal pressure with and without directly increasing cisterna chyli pressure on intestinal wet-to-dry ratio and intestinal ascites formation rate were determined. Target values for portal and cisterna chyli pressures were determined following elevation of inferior vena caval pressure to levels seen in patients with obstructive caval disease. RESULTS: Direct elevation of portal pressure (P(port)) alone to 17.5 mm Hg caused a significant increase in intestinal wet-to-dry ratio (3.98 +/- 0.24 vs. 3.40 +/- 0.43) and the rate of ascites formation (0.36 +/- 0.12 vs. 0.05 +/- 0.03 mL/g dry wt/h). Simultaneous direct elevation of cisterna chyli pressure to 6.0 mm Hg and P(port) to 17.5 mm Hg caused further increases in intestinal wet-to-dry ratio (5.52 +/- 1.20) and ascites formation (0.57 +/- 0.11 mL/g dry wt./h). CONCLUSIONS: Inferior vena caval hypertension increases liver lymph flow that elevates cisterna chyli pressure, which inhibits intestinal lymph flow and augments intestinal edema formation.     

Effect of intestinal circulation on the osmotic balance between the intestinal lumen and blood in awake rats

Total electrolyte concentrations in portal vein and aortic blood of unanesthetized rats were measured continuously by means of ultrafiltrate conductometry. Portal flow rate and mesenteric venous pressure (pmes) could also be measured. The last could be raised to any desired level by a specially developed portal vein clamp. Intraduodenal injections of water (0.5 or 1% BW) were given in a first series of experiments with and without sham-attacking (activating) the animal for 10 s and in a second series with and without raising pmes. Portal flow rate dropped in both cases. But whereas activation led to a decrease in the concentration changes in the v. portae and in arteriovenous differences, a rise in pmes had the opposite effect. Comparison of the total free water change in the v. portae (Mpo) with the quantity of water given (MH2O) revealed that Mpo/MH2O dropped in both series of experiments, provided that pmes was not increased by much more than 2 mm Hg (portal flow did not decrease much under normal). The differing results were explained by taking into account the specificities of blood circulation in the gut wall. The experiments have shown that even transient obstruction of gut tissue perfusion can delay dissipation of concentration imbalance between the gut and parenteral space, thus having adverse effects on the gut cells.     

Origin of the thoracic duct and pancreaticoduodenal lymphatic pathways to the para-aortic lymph nodes

We investigated the afferent and efferent connections of the para‐aortic lymph nodes (group 16 nodes) relative to the origin of the thoracic duct in 85 postmortem cadavers. The origin was usually restricted to groups 16b1‐inter and ‐latero nodes (type I; 90.6%), regardless of whether the union of their efferents occurred at the abdominal or thoracic level. We also occasionally observed thick collecting vessels originating from the dorsal aspect of the pancreaticoduodenal region, running along the right side of and superficial to the celiac plexus and emptying into group 16b1 nodes. The thoracic duct originated occasionally not only from group 16b1 nodes but also from group 16a2 nodes (type II; 9.4%). Moreover, in all 85 specimens, the group 16a2‐inter node often received afferents from the celiac plexus itself or the tight connective tissue between the plexus and diaphragmatic crus, or both. The results support the reliability of the extended D2 lymphadenectomy (D2 + group 16b1 nodes + group 16a2‐inter node) for curative cancer surgery in the pancreaticoduodenal region.     

重组肠三叶因子对急性坏死性胰腺炎大鼠肠黏膜保护作用的研究

目的 探讨重组肠三叶因子(rITF)对急性坏死性胰腺炎(ANP)大鼠肠黏膜的保护作用及其机制.方法 SD雄性大鼠60只,按随机数字表法分为对照组、ANP组、rITF组,每组20只.逆行胰胆管注射5%牛黄胆酸钠100μl/100 g体重制备ANP模型.rITF组制模前后尾静脉注射rITF 0.5mg/100 g体重,对照组及ANP组注射等量生理盐水,术后12、24 h分批处死大鼠.取血检测淀粉酶含量,取末端回肠组织观察病理学改变并予评分、免疫组化法检测肠黏膜NF-κB活性,RT-PCR法检测肠黏膜TNF-α mRNA、ICAM-1 mRNA的表达.结果 ANP组和rITF组血淀粉酶水平较同时点对照组均显著升高.ANP组肠黏膜损伤评分较同时点对照组高(P＜0.05);ANP 12 h组较rITF 12 h组高(P＜0.05),但24 h组间评分无明显差异.对照组、ANP组与rITF组12 h肠黏膜NF-κB阳性细胞数分别为(26±4)个、(55±8)个、(49±4)个;回肠组织TNF-α mRNA相对表达量分别为0.050±0.005、1.040±0.031和0.792±0.0256;回肠组织ICAM-1 mRNA相对表达量分别为0.045±0.010、0.795±0.037和0.400±0.031.ANP组上述各项指标值均较对照组显著增加(P＜0.05或P＜0.01),而rITF下组又较ANP组均显著减少(P＜0.05).结论 重组肠三叶因子对ANP大鼠肠黏膜具有保护作用,其机制可能通过抑制肠黏膜NF-κB活化,下调TNF-αmRNA、ICAM-1 mRNA表达.     

克罗恩病与肠结核的临床分析与比较

目的对克罗恩病(CD)与肠结核(IT)进行临床分析和比较,找出对鉴别诊断有帮助的要点。方法回顾性分析我院1983年~2004年间住院的62例CD患者和21例IT患者的临床资料。结果CD男性多见。临床表现、各种并发症的出现、实验室检查、腹部B超/CT以及消化道造影均对鉴别诊断帮助不大,CD的肠黏膜活检诊断率低。CD与IT的常见部位都是回肠及回盲部,但CD可累及直肠,吻合口病变为77.4%。CD纵行溃疡仅占13.6%,而环形溃疡却占26.7%,回盲瓣受累22.2%,IT瘘管形成并不罕见(14.3%)。CD肠系膜淋巴结最大直径为(10±3)mm,均无上皮样肉芽肿,而IT肠系膜淋巴结最大直径为(18±5)mm,P<0.01,均有上皮样肉芽肿,41.2%有干酪样坏死。CD裂隙溃疡多于IT(P<0.01)。CD中全层炎、淋巴组织增生、黏膜下层水肿均比IT多(P<0.05)。结论CD与IT的鉴别需要多方面综合判断,手术标本的病理对鉴别有重要意义。     

腹腔镜胆囊切除术中粗大胆囊管的处理

目的:探讨腹腔镜胆囊切除术(LC)中粗大胆囊管的处理方法.方法:1995-10/2004-12施行LC 640例,发现胆囊管明显增粗46例,其中胆囊管直径为0.4-0.6 cm.0.6-0.8 cm,0.8 cm以上的例数分别为21,14和11例.分别采用阶梯施夹法(12例)、大号钛夹法(5例)、圈套器法(1例)、结扎后再施夹法(22例)和结扎法(6例)处理增粗的胆囊管.结果:全组46例患者手术顺利,术后无胆漏及其他并发症发生.结论:在LC中,可选用阶梯施夹法、大号钛夹法、圈套器法、结扎后再施夹法和结扎法等牢固处理增粗的胆囊管.如果结扎技术熟练,结扎法可适用于各种情况,可做为首选.     

重组人生长激素对急性心肌梗死大鼠冠状动脉侧支循环的影响

目的 :探讨重组人生长激素 (rh GH)对急性心肌梗死 (AMI)大鼠冠状动脉侧支循环及血管内皮细胞生长因子 (VEGF)、成纤维细胞生长因子 (bFGF)的影响。方法 :5 0只Wistar大鼠经 10 %戊巴比妥钠麻醉后开胸 ,剪开心包腔 ,经左冠状动脉前降支结扎术致其发生AMI ,术后 2 4h存活者 37只被随机分为治疗组 (19只 )和对照组 (18只 )。治疗组以rh GH 0 .2 5IU/kg肌内注射 ,对照组肌内注射同等容积的0 .9%氯化钠溶液 ,3周后处死大鼠 ,开胸经升主动脉向冠状动脉内灌注 4 %多聚甲醛 2 0～ 30min固定心脏 ,心脏标本经切片处理。分别测定血浆和心肌的VEGF、bFGF的量及左室毛细血管密度。结果 :治疗组与对照组在AMI后 3周其血浆bFGF、VEGF浓度均较实验开始时明显增加 (P <0 .0 5 )。治疗组较对照组升高更加显著 ,分别为 (6 8.72± 4 .5 7)∶(35 .6 0±4 .31)和 (4 7.0 5± 5 .13)∶(32 .13± 5 .70 ) (均P <0 .0 5 )。大鼠心肌内bFGF及VEGF治疗组均较对照组高 ,分别为 (79.0 5± 6 .96 )∶(30 .7± 3.4 9)和 (72 .0 5± 6 .73)∶(39.33± 6 .78) (均P <0 .0 1)。血浆bFGF、VEGF的浓度与心肌内毛细血管密度呈正相关 (r分别为 0 .91和 0 .86 ,均P <0 .0 1)。结论 :rh GH能促进AMI大鼠心肌细胞生长因子bFGF和VEGF的表达和分泌     

血小板活化因子对幼鼠肠道免疫屏障功能的影响

目的:探讨血小板活化因子(plateletactivatingfactor,PAF)对肠黏膜分泌型IgA(secretoryIgA,SIgA)的影响.方法:用50μg/kg和65μg/kgPAF对大鼠进行腹腔注射(1μL/g),不同时间点处死动物,应用双抗体-PEG放射免疫法测定肠黏膜中SIgA含量,常规苏木精-伊红染色,光镜观察形态学改变.结果:PAF65组回肠0.5,1.5,3h可见绒毛水肿,固有层血管充血,间质淋巴管扩张,肠腔炎性渗出,上皮脱落,6,24h绒毛水肿.PAF50组0.5,1.5h可见绒毛水肿,固有层血管充血,3,6,24h绒毛水肿.实验组0.5,1.5,3,6hSIgA均较对照组显著降低(PAF50组分别为0.31±0.03mg/L,0.40±0.10mg/L,P<0.01,0.43±0.13mg/L,0.46±0.11mg/L,P<0.05;PAF65组分别为0.28±0.07mg/L,0.36±0.08mg/L,P<0.01,0.40±0.11mg/L,0.42±0.06mg/L,P<0.05vs0.66±0.10mg/L).0.5h下降幅度最大,随时间推移有逐渐升高趋势.结论:PAF可损害肠黏膜的免疫屏障功能,使SIgA降低.     

Relationship between entero-hepatic bile acid circulation and interdigestive migrating myoelectrical activity in rats

AIM: To investigate the effects of entero-hepatic bile acid circulation on the inter-digestive migrating myoelectrical complex (MMC) in rats. METHODS: Thirty-two rats were divided into four groups. Three pairs of bipolar silver electrodes were chronically implanted in the antrum, duodenum and jejunum. Three groups of them were ligated around the upper part of common bile duct (CBD). The experiments were performed in conscious and fasting state. The gastrointestinal myoelectrical activity was recorded. Ursodeoxycholic acid (UDCA) and saline were then perfused into stomachs of two groups with CBD obstruction and the effects of them on the MMC were observed. RESULTS: A typical pattern of MMC was observed in normal fasting rats. MMC of antral and duodenal origin disappeared temporarily in earlier stage of CBD obstruction. While MMC of jejunum origin appeared. increased MMC cycle duration was seen after 4 d in rats with CBD obstruction. The MMC after CBD obstruction was characterized by an increased duration of phase Ⅱ-like activity and decreased duration of phase Ⅰ & Ⅲ activity. Perfusion into stomachs with UDCA resulted in a shorter MMC cycle duration and a longer duration of phase Ⅲ of duodenal origin compared to the normal group. CONCLUSION: Entero-hepatic bile acid circulation initiates inter-digestive MMC of duodenal origin.     

Age-related alterations of active pumping mechanisms in rat thoracic duct

OBJECTIVE: To evaluate the age-related changes in active pumping in thoracic duct (TD) from 24-month-old Fisher-344 rats comparing with TD pumping in 9-month rats. METHODS: Lymphatic diameters, contraction amplitude and frequency, ejection fraction, and fractional pump flow were determined in isolated TD preparations. Western blot analyses were performed to evaluate relative levels of eNOS and iNOS in 9- and 24-month-old TD. RESULTS: Stretch-dependent regulation was altered in aged TD especially at higher levels of pressure: the negative inotropy, negative chronotropy and diminished minute pumping (2- to 3-fold decrease) were observed. Physiological NO/imposed-flow-dependent inhibition was completely abolished in aged TD, yet NO-synthase blockade by L-NAME (10(-4) M) increased pumping in a flow-independent manner. Western blot analyses indicated that the relative levels of eNOS were decreased approximately 7-fold in the 24-month-old TD when compared with 9-month-old TD; whereas iNOS levels were increased approximately 10-fold in 24-month-old TD. CONCLUSIONS: These data provide the first evidence that stretch- and imposed-flow-dependent regulatory mechanisms are greatly altered in aged TD. These alterations of active pumping mechanisms in TD appear to be related with age-related disturbances in NO-dependent regulatory pathways, and may reflect diminished lymphatic muscle contractility as well as altered lymphatic endothelium function.     

Effect of Pluronic L-81 on intestinal lipoprotein secretion in the rat

The hydrophobic nonionic detergent Pluronic L-81 has been shown to lower plasma very-low-and low-density lipoprotein cholesterol, thus preventing diet-induced atherogenesis. The major effect of this agent is a pronounced interference with intestinal lipid metabolism. For studying mesenteric lymph lipoproteins during detergent exposure, a combined micromorphological and biochemical assessment of mucosa and lymph during steady-state lipid absorption was performed. Pluronic L-81 was infused intraduodenally at a constant rate in combination with mixed micellar solutions or saline in mesenteric lymph fistula rats. Pluronic L-81 impairs transepithelial lipid flux during fat absorption, trapping export lipids within the enterocytes and leading to a cytosolic and endoplasmic reticulum lipid accumulation sparing the Golgi region. Pluronic L-81 markedly (P<0.001) reduces mesenteric triglyceride, phospholipid, and total cholesterol secretion almost exclusively by a reduction of chylomicron formation. Chylomicron and very-low-density lipoprotein lipid composition was only insignificantly altered, except for somewhat higher phospholipid/triglyceride ratios. The chylomicron apoprotein pattern was almost unaffected. Thus, chylomicron formation decreased dramatically without major compositional alterations. The reduction of lipid and apoprotein secretion without particle augmentation is not in favour of a selective interference of Pluronic L-81 with intestinal apoprotein B-48 secretion.Parts of this work have been presented at the Annual Meeting of the American Gastroenterological Association, Washington, DC, May 1989, and published in abstract form (1).     

Effect of lovastatin on cerebral circulation in spontaneously hypertensive rats

Statins, which are often given to hypertensive patients, reduce the incidence of stroke. However, their effects on the cerebral circulation have been scarcely studied, although lovastatin has been reported to reduce hypertension-induced renal arteriolar hypertrophy. We examined the structure and mechanics of cerebral arterioles and the lower limit of cerebral blood flow (CBF) autoregulation in spontaneously hypertensive rats (SHR) that were untreated (n=9) or treated for 1 month with lovastatin (n=12; 20 mg x kg(-1) x d(-1)) and in untreated Wistar-Kyoto rats (WKY; n=8). We studied the lower limit of CBF autoregulation by repeated measurement of CBF (arbitrary units; laser Doppler) and internal arteriolar diameter (microm; cranial window) at baseline and during stepwise hypotension. Stress-strain relationships were calculated from repeated measurement of internal arteriolar diameter during stepwise hypotension and cross-sectional area (CSA) of the vessel wall in maximally dilated cerebral arterioles (EDTA, 67 mmol/L). Lovastatin slightly reduced mean arterial pressure (treated, 153+/-3 versus untreated, 171+/-5 mm Hg, P<0.05; WKY, 106+/-3 mm Hg) and normalized CSA (treated, 826+/-52 versus untreated, 1099+/-16 microm(2), P<0. 05; WKY, 774+/-28 microm(2)). Stress-strain curves show that lovastatin also attenuated the increase in passive distensibility. Lovastatin had no effect on the external diameter of cerebral arterioles or the lower limit of CBF autoregulation. Our results show that although lovastatin has substantial effects on arteriolar mechanics and wall CSA, it has little effect on internal diameter. This phenomenon may explain its lack of effect on CBF autoregulation.     

丁酸钠对DMH诱导大鼠肠道肿瘤的作用

目的:观察1,2-二甲基肼(1,2-dimethy lhydrazine,DMH)是否可以诱导出小肠肿瘤,并与大肠进行比较.并探讨丁酸钠(sodium butyrate,NaBt)对DMH诱导肠道肿瘤的作用.方法:实验动物用SPF级♂Wistar大鼠,大小为8-9周龄,共分4组:DMH组、DMH+NaBt组、NaBt组、对照组.实验30-32wk之后过量麻醉使大鼠安乐死,取出小肠和大肠,观察肿瘤部位、数量、大小等;然后用10%甲醛固定,制作病理切片,观察各部位组织学改变.结果:实验结束时DMH组大鼠死亡率60.00%(18/30),DMH+NaBt组死亡率48.00%(12/25).DMH组肠道肿瘤发生率66.67%(8/12),4只肿瘤单发,4只多发,荷瘤率1.33(16/12),小肠肿瘤4个,大肠肿瘤12个;DMH+NaBt组肠道肿瘤发生率84.62%(11/13),6只为单发肿瘤,5只多发,荷瘤率1.46(19/13),小肠肿瘤3个,大肠肿瘤16个.两组之间肿瘤发生率及荷瘤率均无统计学差异.无论是DMH组还是DMH+NaBt组,结肠肿瘤发生率都高于小肠肿瘤,统计学有显著性差异(75.00%vs25.00%,P<0.05;84.21%vs15.79%,P<0.01).DMH组中肿瘤平均体积>0.05cm3个数占37.5%;DMH+NaBt组中肿瘤平均体积>0.05cm3个数占73.68%,两组肿瘤大小有统计学差异(37.50%vs73.68%,P<0.05).与DMH+NaBt组相比,DMH组浸润深度多局限于黏膜层内,有统计学差异(43.75%vs10.53%,P<0.05).结论:DMH也可诱导大鼠小肠肿瘤的发生,但发生率明显低于大肠肿瘤;NaBt可能促进肿瘤生长,关于NaBt对DMH诱导的肠道肿瘤作用仍需做进一步的深入研究.     

糖尿病大鼠小肠Cajal间质细胞及干细胞因子的变化及半夏泻心汤的干预作用

[目的]观察糖尿病（diabetes mellitus,DM）大鼠小肠Cajal间质细胞（ICC）及干细胞因子（stem cell faetor,SCF）表达的变化及半夏泻心汤的干预作用。[方法]除10只大鼠作为正常组外,其他大鼠采用腹腔注射STZ复制DM模型后随机分为DM组、半夏泻心汤组及西药组。半固体营养糊灌胃测定各组大鼠小肠推进率,免疫组化检测c-Kit及SCF在小肠组织中的表达;Western blot检测小肠组织c-Kit蛋白、SCF蛋白表达。[结果]半夏泻心汤组与西药组大鼠的体质量、小肠推进率、c-Kit及SCF阳性细胞数、c-Kit蛋白及SCF蛋白的表达均较DM组明显增加（均P〈o．05）;半夏泻心汤组与西药组大鼠的血糖值较DM组明显降低（P〈0．05）。半夏泻心汤组与西药组之间差异无统计学意义（均P〉0．05）。[结论]半夏泻心汤可以促进DM大鼠小肠肌间神经丛c-Kit、SCF的表达,提示对受损的DM大鼠小肠ICC、SCF有部分恢复作用,从而对DM大鼠的小肠动力障碍有一定的改善作用。     

Effect of Selenium on 1,2-dimethylhydrazine-induced intestinal cancer in rats

PURPOSE: This study was designed to determine the cancer prevention and therapeutic effects of selenium on rats treated with 1,2-dimethylhydrazine (DMH). METHODS: One hundred sixty Spraque-Dawley male rats were divided into seven groups and received 20 mg/kg/week DMH, subcutaneously for 20 weeks. Two different dosages of selenium (8 and 4 ppm) were administered to the rats through drinking water during DMH treatment (B and C groups) or one month before and during DMH treatment (D and E groups). The rats of Groups A (control group), B, C, D, and E were killed immediately after the last DMH injection. The incidence of intestinal cancer in each group was compared. Eight ppm selenium was also administered to rats after DMH treatment (Group F), and survival times were observed and compared with Group G (treated with DMH only). RESULTS: Rats of Groups B and D received 8 ppm selenium and had a significantly decreased incidence of intestinal cancer (from 65.8 percent (Group A) to 33.3 percent (Group B) and 27.8 percent (Group D);P=0.0225 and 0.0038). Rats receiving 4 ppm selenium had a relatively decreased incidence of intestinal cancer (from 65.8 percent (Group A) to 44.4 percent (Group C) and 47.1 percent (Group E) but P> 0.05). Survival time of Groups F and G showed no difference. CONCLUSIONS: Eight ppm selenium provided via drinking water has a significant intestinal cancer prevention effect in the presence of a high dose of DMH (20 mg/kg×20 weeks), and the cancer therapeutic effect of selenium is doubtful in this animal model.Supported by Grant NSC 76-0412-B016-29 from the National Science Council, Republic of China.Read at the meeting of the XIII Biennal Congress of the International Society of University Colon and Rectal Surgeons, Graz, Austria, June 24 to 28, 1990.