ABSTRACT
Objective To observe the effects of gossypol on expressions of transforming growth factor-β1 (TGF-β1), fibronectin (FN) and 11β-hydroxysteroid dehydrogenase (11β-HSD) in nephridial tissue in rats with diabetes mellitus. Methods Thirty male Sprague-Dawley rats were randomly divided into three groups: normal control, type 2 diabetes and gossypol treatment group . After high-fat feeding for 4 weeks, the later two groups were injected with low dosage strepozotocin (30 mg/kg) intraperitoneally to induce type 2 diabetic rat model. The rats in gossypol treated group were given gossypol at the dosage of 15 mg/kg once per day for 4 weeks by gavage. And since the 5th week, the times of gavages had been changed into once per week at the same dosage and lasted to the 12th week . The levels of blood glucose, total cholesterol (TC), low density lipoprotein-cholesterol (LDL-c) were measured. Additionally, the morphological changes of the kidney were studied by light microscopy and transmission electron microscopy respectively. The mRNA expressions of TGF-β1, FN, 11β-HSD and 11β-HSD2 in nephridial tissue were assayed by semi-quantity RT-PCR. The protein expressions of TGF-β1 and FN in nephridial tissue were determined by immunohistochemistry. Results The blood levels of glucose, TC and LDL- c were increased significantly in type 2 diabetic group compared with normal control group(P<0. 01). The volume of glomerulus and the deposition of PAS positive substance in the glomerular interstitium were increased under light microscopy, and the glomerular basal membrane was thicker in type 2 diabetic group than those in normal control group under transmission electron microscopy. The mRNA and protein expressions of TGF-β1 and FN were increased(P<0. 01), and the mRNA expression of 11β-HSD2 was decreased(P<0. 05), while the mRNA expression of 11β-HSD1 was unchanged in type 2 diabetic group compared with normal control group. After the treatment of gossypol, the level of the blood glucose was significantly decreased(P< 0. 01), and the levels of TC, LDL-c showed a trend of decrease but had no statistical differences compared with type 2 diabetic group. The morphology of nephridial tissue was ameliorated in gossypol treatment group. The mRNA and protein expressions of TGF-β1 and FN were decreased(0. 16± 0. 02,0. 22±0. 05 ; 0. 24±0. 06,0. 33±0. 07, P< 0. 05), while the mRNA expressions of 11β-HSD1 and 11β-HSD2 were unchanged compared with type 2 diabetic group. Conclusions Gossypol can relieve the pathologic changes of nephridial tissue, inhibit the expressions of TGF-β1 and FN through decreasing blood glucose of rats with diabetes mellitus.
ABSTRACT
AIM:To study the effect of gossypol on the cognitive function of type 2 diabetic rats,and to explore its mechanism. METHODS:Thirty male Sprague-Dawley rats were divided into three groups randomly:normal group,type 2 diabetic group and gossypol treated group. After fed with high-fat diet for 4 weeks,the later two groups were injected with streptozotocin intraperitoneally to establish type 2 diabetic rat model. The animals in gossypol treated group were given gossypol at dosage of 15 mg/kg once per day for 4 weeks by gavage. Since 5th week,the times of gavages were changed into once per week at the same dosage and lasted to 12th week. Learning and memory abilities of rats were assayed with Morris water maze test. The concentration of blood glucose was measured by biochemical method. The levels of serum corticosterone and insulin were detected by enzyme-linked immunosorbent assay and radioimmunoassay,respectively. The protein expressions of 11?-HSD1 and GR in cerebral cortex and hippocampus were determined by Western blotting. The morphological changes of cerebral cortex and hippocampus were observed under light microscope and transmission electronic microscope,respectively. RESULTS:Compared to normal group,the karyopyknosis,dilation of golgiosome and mitochondria swelling of neuron from cerebral cortex and hippocampus were prominent in diabetic group. The concentrations of blood glucose,serum corticosterone and insulin increased significantly (P
ABSTRACT
AIM:To observe the effect of the extract of Ginkgo biloba(EGB)on pituitary-testicular axis and the mRNA expressions of luteinizing hormone receptor(LHR)and steroidogenic acute regulatory protein(StAR).METHODS:Thirty male Sprague-Dauley rats were divided into three groups randomly:normal control group,type II diabetic group and EGB treatment group.After fed with high-fat diet for 4 weeks,the later two groups were injected with strepozotocin intraperitoneally to induce type II diabetes mellitus.The EGB treatment group was given EGB at the dose of 50 mg/kg once a day for 12 weeks by intragastric administration.The normal control and diabetic group were given normal saline of equal volume per day for 12 weeks.The indices of blood glucose,insulin and low-density lipoprotein-cholesterol(LDL-c)were measured.The morphologic change of testicular tissue was observed under light microscopy(LM)and transmission electron microscopy(TEM)respectively.The concentrations of blood luteinizing hormone(LH)and testosterone(T)were assayed by the technique of enzyme linked immunosorbent assay(ELISA).The mRNA expressions of LHR and StAR from Leydig cells were detected by RT-PCR.RESULTS:The concentrations of blood glucose,insulin and LDL-c increased obviously,and the testis weights lessened obviously in type II diabetic groups compared to those in normal control groups.Rare spermatogenic cells of seminiferous tubule and germinal arrest were observed in diabetic group under LM.Ultrastructural analysis of testicular tissue by TEM showed dilation of the endoplasmic reticulum and mitochondrial swelling in Leydig cell and sertoli cell in diabetic group.The level of blood LH and T decreased in typeⅡ diabetic groups in comparison with that in the normal control group.Compared to normal groups,the mRNA expression of StAR in type Ⅱ diabetic groups decreased,while the mRNA expression of LHR increased.After the treatment of EGB,the pathological change of testis was relieved,the concentrations of blood glucose,insulin and LDL-c were decreased,the level of blood LH and T,and the mRNA expression of StAR were increased,and the mRNA expression of LHR descended compared to type Ⅱ diabetic groups.CONCLUSION:EGB may increase the LH-induced testosterone production by correcting metabolic disorder of glucose and lipid,improving the function of pituitary-testicular axis and regulating the expression of LHR and StAR mRNA.