RESUMO
OBJECTIVE:To investigate the effects of calcium dobesilate on the ultrastructure of glomerular basement membrane(GBM)in diabetic rats.METHODS:30rats underwent unilateral nephrectomy,of whom,10were assigned to the normal control group(group NC),another20were induced to diabetic models(DM)by intraperitoneal injection of1%STZ,the models which have finished were divided into DM control group and calcium dobesilate group(group DD),each group admin?istered with distilled water and calcium dobesilate respectively,12weeks later,the change in the ultrastructure of kidneys and endogenous creatinine clearance rate(CrCl)in each group were observed.RESULTS:After12weeks,endogenous CrCl in group DD was significantly higher than that in group DM;Electron microscope showed that thickening of glomerular capillary basement membrane in group DD was less than that in group DM.CONCLUSION:Calcium dobesilate could improve the ul?trastructure in kidney of diabetic rats,prevent GBM thickening,and protect filtration barrier of renal glomerulus.
RESUMO
To observe the effects of calcium dobesilate on the expression of glomerular tissue inhibitor of metalloproteinase 1 (TIMP1), collagen Ⅳ, and ultrastructure of glomerular basement membrane in diabetic rats, rats model of diabetes was established by unilateral nephrectomy and intraperitoneal injection of 1% STZ (55 mg/kg), and rats were administered calcium dobesilate 100 mg/kg (DD group) or distilled water (DM group) respectively. 12 weeks later, the changes in the renal ultrastructure and creatinine clearance rate (Ccr) were examined in each group. The expression of glomerular TIMP1 and collagen Ⅳ were studied by immunohistochemical staining. Our results showed that after 12 weeks, the Ccr in DD group increased and was significantly higher than that in DM group. Electron microscopy showed that thickness of glomerular capillary basement membrane (GBM) in Group DD was less than that of DM group. No hyperplasia of collagen fibers was found, and the distance between the holes of endothelial cells in DD group was not as even as that in the normal group, but more even than that of DM group, and podocyte processes was still in order. Immunohistochemical staining of glomeruli showed that expression of TIMP1 and collagen Ⅳ in DD group were significantly less than those of DM group DM. It is concluded that calcium dobesilate can improve diabetic nephropathy by inhibiting the over- accumulation of collagen Ⅳ and calcium dobesilate may also contribute to diabetes by inhibiting the expression of TIMP1.
RESUMO
The effects of benazepril on P42/44MAPK, angiotensin Ⅱ expression in renal tissue and renal pathological change of the experimental diabetic rats were assessed and the possible mechanism of benazepril's renoprotective effect was explored. Adult male Wistar rats, 11-12 weeks age,weighing initially 160 to 200 g were randomly allocated into 2 groups: control group (A, n=6) and experimental group (n= 12). Diabetic rats in experimental group were rendered diabetic by intraperitoneal injection of Streptozotocin (60 mg/kg body weight), and randomly subdivided into B group (diabetic control) and C group (diabetic rats treated with benazepril, 6 mg/kg every day).Studies were performed 8 weeks after induction of diabetes. Twenty-four h urine of every rat was collected to detect urine creatinine. Serum glucose concentration and serum creatinine were determined by collecting blood samples from the inferior vena cava. Body and kidney weight were recorded. Creatinine clearance (Ccr) and ratio of kidney weight to body weight were calculated. Plasma and renal tissue angiotensin Ⅱ concentration was assayed by radioimmunoassay (RIA). The phospo-p44/42MAPK protein expression was detected by Western-blot. The results showed that benazepril had no significant effect on the blood glucose level in diabetic rats in two experimental groups.Ccr and ratio of kidney weight to body weight were increased in group B (P＜0. 01) as coapared with normal rats at the end of the 8th week. At the end of the 8th week, Ccr in group C was lower than that in group B (P＜0.01). The ratio of kidney weight to body weight in group C was lower than that in group B at the 8th week. There were glomeruli hypertrophy and slight or moderate mesangium proliferation in diabetic rats, while there was fragmentally proliferative mesangium in group C at the end of the 8th week. Renal tissue angiotensin Ⅱ concentration was significantly increased in group B, while benazepril could significantly decrease the concentration of angiotensin Ⅱ in renal tissue. The expression of the phospo-p44/42MAPK protein in group B was increased as compared with group A, while it was decreased in group C as compared with group B. P42/44MAPK pathway participated in the pathogenesis of diabetic nephropathy. Benazepril can eliminate high filtration of glomeruli, decrease proteinuria, and eliminate renal hypertrophy as well as renal destruction. Renoprotective effect of benazepril in diabetic rats may be partly related to the inhibition of angiotensin Ⅱ -P42/44MAPK pathway.
