消渴颗粒剂对大鼠系膜细胞增殖和TGF-β1表达的影响

目的：观察消渴颗粒剂对高糖刺激后系膜细胞增殖和TGF-β1表达的影响，以探讨消渴颗粒剂治疗糖尿病肾病的机理。方法：培养正常大鼠系膜细胞，经相差显微镜、扫描电镜观察，免疫细胞化学染色actin和desmin梁色均为阳性，证实为系膜细胞后，进行实验。高浓度葡萄糖刺激系膜细胞，加入中药含药血清后，用MTY法和激光共聚焦显微镜分别观察消渴颗粒剂含药血清对高糖刺激后系膜细胞增殖和TGF-β1表达的影响。     

阿司匹林对高糖和高胰岛素诱导的血管平滑肌细胞内iNOS含量的影响

目的:探讨阿司匹林对高糖和高胰岛素诱导的大鼠血管平滑肌细胞(vasculersmoothmusclecells,VSMCs)内诱导型一氧化氮合酶(inducible nitric oxide synthase,iNOS)含量变化的影响,以及高糖、高胰岛素状态下细胞内iNOS含量变化与上清液中NO含量变化的相关性。方法:组织贴块法原代培养大鼠胸主动脉VSMCs,用阿司匹林干预高糖和高胰岛素诱导后的VSMCs。实验设正常对照组(CON组)、高糖组(HG组)、高胰岛素组(HI组)、高糖和高胰岛素组(HGI组)、阿司匹林2.50mmol/L+HG组(AHG组)、阿司匹林2.50 mmol/L+HI组(AHI组)、阿司匹林2.50 mmol/L+HGI组(AHGI组),每组样本数为6。应用大鼠iNOS ELISA试剂盒检测细胞内iNOS的变化情况(OD值),NO试剂盒检测培养基上清液中NO含量,并分析高糖、高胰岛素状态下两者的相关性。结果:高糖、高胰岛素均能使VSMCs内iNOS含量减低(P<0.05),高糖和高胰岛素联合能使VSMCs内iNOS含量明显减低(P<0.01);阿司匹林能使高糖、高胰岛素刺激后VSMCs内iNOS含量升高(P<0.05),并能显著提高高糖和高胰岛素联合刺激后VSMCs内iNOS含量(P<0.01)。高糖、高胰岛素、高糖和高胰岛素联合均能使培养基上清液中NO含量减低(P<0.05);阿司匹林能提升上述三者刺激后上清液中NO含量(P<0.05)。HGI组中iNOS的降低与上清液中NO的降低、AHGI组iNOS的升高与上清液中NO的升高并不表现出相关性(r=0.778,r=0.632,均P>0.05)。结论:阿司匹林能提高高糖和高胰岛素联合刺激后VSMCs内iNOS的含量,并能提高培养液中NO的含量,但细胞内iNOS含量可能不是决定培养液中NO含量的唯一因素。     

增加n-6脂肪酸对高脂诱导的大鼠胰岛素抵抗和血清游离脂肪酸谱的影响

目的探讨喂养占总热量59％的饱和脂肪酸及n-6脂肪酸代替其中20％热量后，对胰岛素抵抗和血清游离脂肪酸谱的影响。方法45只雄性Wistar大鼠分为3组。对照组喂饲普通饲料，高脂组喂饲提供59％热卡的饱和脂肪酸高脂饲料，n-6脂肪酸组喂饲高脂饲料，其中提供20％热量的饱和脂肪酸由豆油中的C18：2代替。各组共喂饲11周后测定糖耐量、空腹胰岛素、胰岛素耐量、胰岛素抵抗指数、血清瘦素、血脂、血清游离脂肪酸谱。结果①高脂组大鼠从第4周开始体重明显升高，糖负荷后血糖、糖耐量试验中葡萄糖曲线下面积、皮下注射胰岛素后血糖及胰岛素耐量试验中葡萄糖曲线下面积、血清胰岛素、胰岛素抵抗指数、血清瘦素、血清胆固醇和甘油三酯含量均较正常对照组明显升高。高脂组大鼠血清游离脂肪酸谱中，饱和脂肪酸及18烷酸明显升高，不饱和脂肪酸及18碳2烯酸、18碳3烯酸、20碳4烯酸、n-6脂肪酸和n-3脂肪酸均明显下降。②n-6脂肪酸组从第1～10周体重均较高脂组明显减轻，糖负荷后血糖和糖耐量试验中葡萄糖曲线下面积、皮下注射胰岛素后40min、90min血糖及胰岛素耐量试验中葡萄糖曲线下面积、血清胰岛素、胰岛素抵抗指数、血清胆固醇、甘油三酯和低密度脂蛋白含量均较高脂组明显降低；血清瘦素水平、高密度脂蛋白、18碳2烯酸较高脂组明显升高。结论n-6脂肪酸代替诱导大鼠胰岛素抵抗的饱和脂肪酸的20％热量后可以降低胰岛素抵抗，同时血清中18碳2烯酸提高。     

高糖和不同浓度胰岛素对血管平滑肌细胞增殖的影响

目的:探讨高糖和不同浓度胰岛素对大鼠血管平滑肌细胞(vascular smooth muscle cells,VSMCs)增殖的影响及可能机制.方法:组织贴块法原代培养大鼠胸主动脉VSMCs,用高糖和不同浓度胰岛素诱导细胞增殖.实验设对照组、高糖组、高糖和不同浓度胰岛素组.采用四甲基偶氮唑盐[3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide,MTT]比色法测定VSMCs增殖;免疫细胞化学技术检测VSMCs增殖细胞核抗原(proliferating cell nuclear antigen,PCNA)含量;RT-PCR技术检测VSMCs中PCNA mRNA的表达量;NO试剂盒检测培养基上清液中NO含量.结果:高糖能诱导VSMCs的增殖,而胰岛素则呈剂量依赖性地协同高糖诱导VSMCs增殖,最大作用效果出现在300 mU/L胰岛素培养的第5天;高糖可以使PCNA蛋白含量增加,而高糖和高浓度胰岛素(300 mU/L)合用则可使PCNA蛋白含量显著增加;高糖可使PCNA mRNA表达量增高,而高糖和高胰岛素(300 mU/L)合用则可使PCNA mRNA表达量显著增高;高糖可使NO含量降低,而高糖和高胰岛素(300 mU/L)合用则可使NO含量显著降低.结论:胰岛素呈剂量依赖性地协同高糖促进VSMCs增殖,使VSMCs PCNA蛋白含量和PCNA mRNA表达量增高,并协同高糖降低NO的产生.     

尿胰岛素测定及其临床意义的探讨

测定血清(浆)总、游离胰岛素了解糖强病(DM)人的胰岛β细胞贮备功能以评价胰岛素的疗效。胰岛素可在尿液、唾液等体液中测出，并有人作为临床疗效观察指标。本文同时测定血胰岛素(P-INS)，尿胰岛素(U-INS)含量，探讨尿液胰岛素的临床价值。     

苦瓜提取物对实验性Ⅱ型糖尿病大鼠的血糖的影响

目的:观察苦瓜提取物对链脲霉素引起的Ⅱ型糖尿病大鼠模型的血糖、血清胰岛素及血脂的影响。方法:大鼠尾静脉注射小剂量链脲霉素25mg·kg-1,同时喂以高糖高脂饲料复制Ⅱ型糖尿病大鼠模型.然后给予苦瓜提取物14,28,56mg·kg-1,连续灌胃给药4周后,测定血糖、血清胰岛素及血脂。结果:苦瓜提取物14,28,56mg·kg-1能降低实验性Ⅱ型糖尿病大鼠血糖及血清胰岛素水平,能升高HDL-C含量,而对血脂其它指标无明显影响。结论:苦瓜提取物对Ⅱ型糖尿病大鼠有治疗作用。     

多囊卵巢综合征妇女内源性胰岛素释放与睾酮反应的相关性研究

本研究以36例PCOS妇女和20例正常月经周期妇女为研究对象。通过测定激素基础水平,观察在糖耐量试验中胰岛素对糖负荷的反应和睾酮的变化以及分析体脂与胰岛素的关系。发现PCOS妇女有较高的空腹血糖水平、空腹血清胰岛素与空腹血清睾酮呈显著正相关(r=0.65,P<0.01)。在糖负荷期PCOS组血清胰岛素释放显著高于对照组(P<0.01),同时,总睾酮与总胰岛素呈正相关(r=0.69,P<0.01)。PCOS肥胖者总胰岛素对糖负荷的反应最大,对照非肥胖者反应最小(F=3.02,P<0.01)。PCOS妇女体脂百分率与空腹血清胰岛素呈正相关(r=0.523,P<0.05)。由此提示(1)PCOS妇女内源性胰岛素释放是PCOS雄激素增高的原因之一;(2)PCOS妇女体脂过多可能在PCOS的高胰岛素血症和胰岛素抵抗中起有部分作用。     

血清胰岛素RIA在高血压病研究中的应用

文献报道在相当一部分高血压患者中存在高胰岛素血症和糖代谢异常,并指出这种胰岛素抵抗状态可能是这种病人血压升高的作用机制之一,为了解高血压患者血清胰岛素变化并探讨血清胰岛素放射免疫测定对高血压病的研究价值,本文对104例高血压病患者及80例正常对照组空腹胰岛素水平及胰岛素释放试验结果进行比较,现报道如下。     

消渴颗粒剂对糖尿病肾病大鼠血糖、血脂含量的影响

目的:观察糖尿病肾病大鼠血糖、胆固醇、甘油三脂含量的变化以及消渴颗粒剂对其的影响。方法:采用3/4肾切除,腹腔一次性注射STZ复制大鼠糖尿病肾病模型。将动物分为模型组、消渴颗粒剂治疗组、阳性药对照组和假手术组。每组大鼠于注射STZ后1、2、3、4、5周尾尖取血测定空腹血糖、血清肌酐、血清胆固醇和血清甘油三脂含量。各组大鼠于注射STZ后6周杀检,进行肾脏形态学观察。结果:注射STZ后6周,模型组大鼠有不同程度的肾小球硬化。中药治疗组上述病变明显轻于病理组。注射STZ后第1、2、3、4、5周,模型组血清肌酐明显高于假手术组(P＜0.05),治疗组则明显低于模型组和阳性对照组。注射STZ后1、2、3、4、5周模型组空腹血糖、血清胆固醇明显高于假手术组(P＜0.05),血清甘油三脂在注射STZ后1、2、3、5周明显高于假手术组(P＜0.05);消渴颗粒剂治疗组和阳性对照药组与模型组同期比较病变明显减轻。空腹血糖和血清胆固醇、甘油三脂含量呈正相关。结论:采用此方法成功地复制了大鼠糖尿病肾病模型,糖尿病肾病大鼠血糖增高可能引起血脂增高,消渴颗粒剂治疗糖尿病肾病的途径之一是降低大鼠血糖、血清胆固醇、血清甘油三脂含量,从而改善肾小球病变。     

脑梗塞患者血清胰岛素、胰高糖素RIA

为了探讨脑梗塞患者血清中胰岛素（Ins)。胰高糖素（Gluc)含量，我们从1993年5月-1994年4月对108例脑梗塞患者进行了Ins,Gluc含量测定，并探讨了它与血液葡萄糖（Glu)之间的关系，同时与正常组进行了比较，现报道如下。     

Studies on the mechanism of alloxan-diabetes potentiation of carbon tetrachloride-induced liver necrosis.

Carbon tetrachloride (CCl4)-induced liver necrosis in alloxan diabetic rats is markedly more intense than in controls as established by determination of isocitric dehydrogenase activity in plasma or by histological techniques. The covalent binding (CB) of CCl4 reactive metabolites to liver microsomal lipids is higher in alloxan diabetic rats than in controls. Cytochrome c reductase activity remains unchanged in alloxan diabetic rats. All the alterations described above observed in the diabetic animals are reverted by insulin administration. CCl4-induced lipid peroxidation of microsomal lipids, in contrast, is equally intense in controls than in alloxan diabetic animals and it is not modified by insulin treatment. Body temperature in alloxan diabetic animals treated with CCl4 is lower than in controls treated with the hepatotoxin. Results suggest that part of the enhanced necrogenic response of the liver observed in alloxan diabetic rats is due to increased CB to liver cell constituents but available evidence from the present and another work suggest that increased susceptibility of the liver from alloxan diabetic animals play a major role in the potentiation of CCl4 deleterious effects.     

A time-course study of submandibular kallikrein,blood glucose and insulin of alloxan-diabetic and streptozotocin-diabetic rats

A time-course study was carried out of the levels of submandibular kallikrein, serum insulin and blood glucose of rats rendered diabetic by alloxan or streptozotocin. The permanent hyperglycemia seen one day after treatment and the subsequent relative changes in the levels of blood glucose recorded over the following nine days were in agreement with previous observations. A significant reduction in the concentration of submandibular kallikrein did not become apparent until ten days following the injection of alloxan or streptozotocin. Thus the enzyme would not appear to have played either a causal or a preventative role in the production of the hyperglycemic state.Furthermore, in disagreement with previous speculation, the submandibular gland had not compensated for the deficiency of insulin with an increase in production of kallikrein. The fall in the level of serum insulin had preceded the decrease in submandibular kallikrein. However, administration of exogenous insulin over a period of three days did not bring about an increase in the concentration of submandibular kallikrein of the diabetic rats. Thus insulin would not seem to be involved in controlling the level of kallikrein in the submandibular gland.     

Insulin modulates inflammatory and repair responses to elastase-induced emphysema in diabetic rats

As pulmonary emphysema and diabetes mellitus are common diseases, concomitance of both is correspondingly expected to occur frequently. To examine whether insulin influences the development of inflammation in the alveolar septa, diabetic male Wistar rats (alloxan, 42 mg/kg, i.v., n = 37) and matching controls (n = 31) were used. Ten days after alloxan injection, diabetic and control rats were instilled with physiologic saline solution containing porcine pancreatic elastase (PPE, 0.25 IU/0.2 ml, right lung) or saline only (left lung). The following analyses were performed: (i) number of leucocytes in the bronchoalveolar lavage (BAL) fluid of the animals, 6 h after PPE/saline instillation (early time point); and (ii) mean alveolar diameter (μm) and quantification of elastic and collagen fibres (%) 50 days after PPE/saline instillation (late time point). Relative to controls, alloxan-induced diabetic rats showed a 42% reduction in the number of neutrophils in BAL fluid, a 20% increase in the mean alveolar diameter and a 33% decrease in elastic fibre density in the alveolar septa. Treatment of diabetic rats with 4 IU neutral protamine Hagedorn (NPH) insulin, 2 h before elastase instillation, restored the number of neutrophils in the BAL fluid. The mean alveolar diameter and elastic fibre content in alveolar septa matched the values observed in control rats if diabetic rats were treated with 4 IU NPH insulin 2 h before instillation followed by 2 IU/day for the next 50 days. Density of collagen fibres did not differ between the various groups. Thus, the data presented suggest that insulin modulates the inflammatory and repair responses in elastase-induced emphysema, and assures normal repair and tissue remodelling.     

Trehalase activity in genetically diabetic mice (serum, kidney, and liver).

Trehalase activity was determined in serum, liver, and kidney in alloxan treated Swiss mice and in homozygous (Ob/Ob, Db/Db) and heterozygous (Ob/+, Db/m+) diabetic mice. Both alloxan and genetic diabetic mice exhibited a large increase in serum and liver trehalase activity with no change in kidney trehalase activity. The heterozygotes (Ob/+, Db/m+) showed only a slight increase of enzyme activity. Further quantitative differences were noticed between the genetic and alloxan diabetic animals. The liver enzyme activity increased from 10- to more than 20-fold in the liver of the homozygous Ob/Ob and Db/Db strains and only 3-fold (not significant compared to controls) in the alloxan treated animals. The above results suggest a regulatory relationship between the genes coding for trehalase and the enzymes of glucose metabolism activity involved in the development of the metabolic anomalies of diabetes. The structural gene for trehalase may well have survived elimination of selective pressure during phylogenesis and remained part of a co-regulated group of glucose metabolising enzymes. This could explain its sensitivity to mutations affecting glucose metabolism and its sensitivity to insulin directed regulatory mechanisms.     

Serum cholinesterase activity of rats with experimental diabetes

Summary A study was made of the cholinesterase activity of blood serum in intact rats (78) and in rats with induced diabetes (following pancreatectomy-in 46 rats, following alloxan administration, 43 rats). The blood serum cholinesterase activity increased both in induced, postoperative, and alloxan diabetes. There was a relationship between the increase in the cholinesterase blood serum activity and the severity of diabetic disturbances. The greater the blood sugar level the higher was cholinesterase activity.Presented by Acad. V. N. Chemigovskii Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 58, No. 10, pp. 41–44, October, 1964     

Renal injury induced in alloxan diabetic rats. Role of Mycophenolate Mofetil as therapeutic agent

BackgroundRenal injury may develop in uncontrolled chronic hyperglycemia due to increased oxidative stress and release of pro-inflammatory mediators, leading to diabetic complications.MethodsMycophenolate Mofetil (MMF) is an immunosuppressant drug, an inhibitor of inosine monophosphate dehydrogenase (IMPDH), relevant to inflammation processes. MMF effect was tested in alloxan-diabetic rats on selected parameters like oxidative stress, gene expression of tumor necrosis factor-α (TNF-α) and transforming growth factor-β1 (TGF-β1), in relation to microalbuminuria and renal function.ResultsWe found that the onset of microalbuminuria preceded the increase in serum glucose after alloxan treatment. Gene expression of TNF-α and TGF-β1 showed gradual increase after one and two weeks of alloxan administration as compared to the normal group. MMF administration decreased the gene expression of TNF-α and TGF-β1 in kidney tissues, serum glucose, fructosamine, urea, creatinine, C-reactive protein, malondialdehyde, urinary microalbumin and total protein. Histological examination of kidney tissues showed significant improvement in MMF treated rats as compared to diabetic control.ConclusionsMMF modulated renal injury of alloxan diabetic rats. Collective data may support its therapeutic effect but further clinical trials may be requested.     

The effect of alloxan, and alloxan-induced diabetes on the kidney

Alloxan is known to induce diabetic renal changes as well as causing nephrotoxic alterations. However, no ultrastructural study has been performed to differentiate diabetic verses toxic affects of alloxan to the tubule and/or glomerulus. Therefore the present study used the "protected" kidney model to prevent one kidney from being exposed to the alloxan while allowing the other to receive the drug immediately. In all experimental animals the right renal hilum was gently occluded for 5 minutes and then released. This was performed prior to the injection of alloxan. Subsequently, the left renal hilum was occluded at the time of, and for 5 minutes after, alloxan administration (40 mg/kg i.v.). The experimental rats were divided into three groups: untreated diabetics, diabetics treated with protamine-zinc-insulin, and alloxan-treated rats that failed to become diabetic. Three groups of controls were included: one group received an equal volume of saline diluent as the experimental rats but no clamping of either renal hilum; another group received the saline and had the left renal hilum occluded for 5 minutes; and a third group had both the right and left renal hila occluded. All animals were followed and sacrificed after 9 weeks. Endogenous creatinine clearance did not change among groups. Alloxan-treated nondiabetic rats displayed marked interstitial nephritis in unprotected kidneys, while protected kidneys were normal. The diabetic state resulted in mesangial proliferation and focal glomerular basement membrane thickening as well as glomerular capillary endothelial abnormalities and visceral epithelial foot-process fusion. The endothelial changes consisted of focal areas showing a reduction in the size of endothelial fenestrae. All glomerular changes were ameliorated by insulin treatment. We conclude: 1) alloxan per se is distinctly nephrotoxic; and 2) the glomerular endothelium and epithelium are involved early in the course of experimental diabetes.     

Microvascular reactivity in experimental diabetes: responses of male and female rats

OBJECTIVE: To study the influence of sex on the responses of microvessels to vasoactive agents in experimental diabetes. MATERIALS: Diabetes was induced by alloxan (40 mg/kg, iv) in male and female Wistar rats (8-10-week-old). METHODS: Using an image splitter television microscope, mesenteric arteriolar and venular diameter changes induced by topically applied vasoactive agents (histamine, bradykinin, platelet activating factor-PAF, acetylcholine, sodium nitroprusside, noradrenaline and angiotensin II) were examined. RESULTS: Whereas the vasoconstrictor response to noradrenaline was equivalent in normal and diabetic animals, either female or male rats, an increased vasoconstrictor response to angiotensin II was observed in male but not in female diabetic rats in comparison with respective controls. Similarly to that observed in males, the dilator response of microvessels to topically applied bradykinin, histamine and PAF was impaired in female diabetic rats. Whereas reversal of the impaired responses to these agents was obtained by acute treatment of diabetic animals with insulin the altered responses to angiotensin II observed in male diabetic rats were not corrected. Differently from that observed in males, impaired response of microvessels to acetylcholine but not to sodium nitroprusside was observed in female diestrous diabetic rats; acute insulin treatment corrected it. CONCLUSIONS: We conclude that not all the alterations of the microvascular reactivity and the correction by insulin are gender dependent in diabetes.     

Decreased myocardial function and myosin ATPase in hearts from diabetic rats

The effect of diabetes on cardiac function was determined in isolated rat hearts. Diabetes was induced by injection of alloxan (doses ranged from 37.5 to 60 mg/kg body wt), and the heart were removed and perfused in the working heart preparation. Doses of alloxan ranging from 37.5 to 42 mg/kg did not consistently alter cardiac function even though serum glucose was elevated and serum thyroid hormones were reduced. Injection of 45 mg/kg of alloxan caused a large increase in serum glucose and a larger decrease in thyroid hormones. In this case, ventricular function was more consistently depressed after 1-2 wk. Function was not altered 48 h after injection of 60 mg kg of alloxan. However, when animals were given 60 mg/kg of alloxan and then maintained on insulin for 7 days, depressed cardiac function developed within 4 days after the insulin treatment was stopped. The decline in function involved a decrease in heart rate peak systolic pressure, and left ventricular +dP/dt. It was associated with greatly reduced serum thyroid hormones (both T3 and T4) and lower ventricular Ca2+-activated myosin ATPase activity. Fasting of rats for 4 days also resulted in decreased serum T3 and T4, depressed cardiac function (although heart rate was unchanged), and lower Ca2+-activated myosin ATPase activity.