不同病程2型糖尿病患者甲襞微循环状态比较

目的:观察不同病程2型糖尿病(T2DM)患者甲襞微循环障碍程度。方法:600例住院T2DM患者,依病程分为新诊断组、3月～5年组、6年～10年组和>10年组。选取30例健康体检者为对照组。用徐州产HD-WX-10型微循环显微仪,在22～24℃室温下,检测所有对象的左手无名指,观察甲襞微循环形态、流态和袢周状态,并对各组加权积分值、不同程度异常率和部分指标异常进行统计学分析比较。结果:(1)不同病程各组T2DM患者甲襞微循环形态、流态和袢周状态积分均高于对照组,以管袢减少、白微栓、渗出和出血等改变较明显(P<0.01),中度异常患者比例较高。(2)病程10年以内各组患者积分值、部分指标异常率及异常程度无统计学差异(P>0.05)。(3)>10年组患者甲襞微循环流态及袢周形态积分和总积分较其它组增加(P<0.05),中度异常患者比例较高(P<0.01),管袢明显减少,白微栓和渗出显著增多(P<0.01)。结论:T2DM患者存在微循环障碍,病程>10年者较重。     

Arteriolar responses to vasodilator stimuli and elevated P(O2) in renin congenic and Dahl salt-sensitive rats

OBJECTIVES: Angiotensin II suppression leads to impaired vascular relaxation in normotensive animals on a high-salt diet. The goal of this study was to determine whether normal vascular reactivity could be restored by transferring the chromosomal region carrying the Dahl salt-resistant (R) renin gene into the Dahl salt-sensitive (SS) genetic background in a strain of renin congenic rats (RGRR). METHODS: Male RGRR and SS rats were fed low-salt (0.4%) and high-salt (4%) diets for 4 weeks. The responses of cremaster muscle arterioles to acetylcholine (ACh), sodium nitroprusside (SNP), and elevated PO2 were assessed using video microscopy. RESULTS: ACh-induced dilation was significantly enhanced in RGRR on a high-salt diet compared to SS rats, while dilation to the NO donor SNP was similar in both strains. A high-salt diet significantly enhanced arteriolar constriction in response to elevated PO2, in both SS and RGRR rats. CONCLUSIONS: These data suggest that transfer of the chromosomal region containing the renin gene is crucial in the recovery of ACh-induced dilation of arterioles in RGRR rats vs. SS rats, and that factors in the SS genetic background contribute to an enhanced sensitivity to elevated PO2, independent of genes on chromosome 13.     

Cross-sectional study of peripheral microcirculation in diabetic patients with microangiopathy: influence of pancreatic and kidney transplantation

Diabetic vascular lesions and peripheral autonomic neuropathy are both closely linked to long-term metabolic control of diabetes. Transcutaneous oxygen tension (P _tcO₂) measurements were made to elucidate whether autonomic neuropathy disturbs the cutaneous microciculatory blood flow, and whether long-term glucose normalization ameliorates such impairment. Twenty-eight type 1 (insulin-dependent) diabetic patients in whom clinically significant macroangiopathy had been excluded by angiography were studied, subdivided into group An=14; before simultaneous pancreas/kidney transplantation (SPKT); mean age 35 years, range 22–51 years; mean duration of diabetes 24 years, (range 15–32) years and group B (n=14; mean 31 months, range 2–101 months, after successful SPKT; mean age 35 years, range 19–56 years; mean duration of diabetes 22 years, range 14–29 years). On addition there was a group (group C) of age-and sex-matched healthy control subjects (n=14; mean age 35 years, range 23–62 years).P _tcO₂ measurements included basal recordings at 44°C on the leg and the foot, functional recordings at 44°C after arterial occlusion of the limb for 4 min, measurements during breathing 5 l oxygen per minute and finally while standing up (stand up dP ₅₀/dt). All subjects underwent extensive cardiac autonomic testing. In this cross-sectional study the recordings of basal values and of the functional parameters after arterial occlusion and during breathing oxygen did not differ significantly between groups A, B and C. The stand-up dP ₅₀/dt values were not significantly different between groups A and B (0.43±0.02 vs 0.47±0.03 mmHg/s, mean ± SEM); but A+B values were significantly higher than in C (0.22±0.01 mmHg/s;P<0.001). These values were correlated significantly with all parameters of cardiac autonomic neuropathy (r range–0.56 to –0.88;P<0.001). It may be concluded that normalization of blood glucose by pancreatic transplantation is not able to ameliorate peripheral microcirculation, but that measurement of transcutaneous oxygen tension is a possible new technique for quantifying alterations in the venoarteriolar reflex in peripheral diabetic autonomic neuropathy that lead to disturbed peripheral microcirculation in diabetic patients.     

Pancreatic microcirculation in acute pancreatitis

We present a review of the microvascular morphology of the pancreas and microstructure of the pancreatic lobule, and report our experimental results of the investigation of pancreatic microcirculation following acute pancreatitis. Impairment of pancreatic microcirculation in the early phase of acute pancreatitis may play a key role in the progression of this disease. Possible contributory mechanisms include increased vascular permeability, reduced blood flow, leukocyte-endothelial cell interaction and intravascular thrombus formation. Using an in-vivo microscope system and off-line computer analysis, we achieved direct visualization and quantification of changes in microvascular permeability and leukocyte behavior in pancreas with acute pancreatitis. Bradykinin and oxygen radicals have been demonstrated to be involved in the increase of vascular permeability in the early stage of caerulein pancreatitis. Leukocyte adherence to the vessels in the pancreatic microcirculation is a secondary event following permeability changes in acute pancreatitis. Leukocyte infiltration during exacerbation of acute pancreatitis is mediated by leukocyte-endothelial cell interaction via leukocyte integrin CD11b/18.     

Effects of ethyl pyruvate on leukocyte-endothelial interactions in the mesenteric microcirculation during early sepsis treatment

OBJECTIVES:Experimental studies on sepsis have demonstrated that ethyl pyruvate is endowed with antioxidant and anti-inflammatory properties. This study aimed to investigate the effects of ethyl pyruvate on leukocyte-endothelial interactions in the mesenteric microcirculation in a live Escherichia coli-induced sepsis model in rats.METHODS:Male Wistar rats were administered an intravenous suspension of E. coli bacteria or were subjected to a sham procedure. Three hours after bacterial infusion, the rats were randomized into the following groups: a control group without treatment, a group treated with lactated Ringer''s solution (4 mL/kg, i.v.), and a group treated with lactated Ringer''s solution (4 mL/kg, i.v.) plus ethyl pyruvate (50 mg/kg). At 24 h after bacterial infusion, leukocyte-endothelial interactions were investigated using intravital microscopy, and the expression of P-selectin and intercellular adhesion molecule-1 was evaluated via immunohistochemistry. White blood cell and platelet counts were also determined at baseline and 3 h and 24 h after E. coli inoculation.RESULTS:The non-treated and lactated Ringer''s solution-treated groups exhibited increases in the numbers of rolling leukocytes (∼2.5-fold increase), adherent cells (∼3.0-fold), and migrated cells (∼3.5-fold) compared with the sham group. In contrast, treatment with Ringer''s ethyl pyruvate solution reduced the numbers of rolling, adherent and migrated leukocytes to the levels observed in the sham group. Additionally, the expression of P-selectin and intercellular adhesion molecule-1 was significantly increased on mesenteric microvessels in the non-treated group compared with the sham group (p<0.001). The expression of both adhesion molecules was reduced in the other groups, with ethyl pyruvate being more effective than lactated Ringer''s solution. Infusion of bacteria caused significant leukopenia (3 h), followed by leukocytosis with granulocytosis (24 h). There was also an intense and progressive reduction in the number of platelets. However, no differences were observed after treatment with the different solutions.CONCLUSIONS:The presented data suggest that ethyl pyruvate efficiently reduces the inflammatory response in the mesenteric microcirculation in an experimental model of sepsis induced by live E. coli and is associated, at least in part, with down-regulation of P-selectin and intercellular adhesion molecule-1.