Expression Of Tissue-type Plasminogen Activator And Plasminogen Activator Inhibitor In Kidney Of Diabetic Rats And Effect Of Cordyceps Sinensis

ObjectiveTo observe the expression of tissue plasm inogen activator(t-PA),plasminogen activator inhibitor(PAI-1),fibronectin and collagen IV in diabetic rats and to study the change of t-PA,PAI-1,Colâ…£and FN after treated by cordyceps sinensis, and to find the most possible mechanism of this change.Methods1.44 healthy male Wistar rats were divided into four groups randomly as follows:10 normal rats(group N),12 diabetic rats(group M), which were built by intraperitoneal injection of STZ(55mg/kg),11 early intervention rats(treat group1) and 11 late intervention rats(treat group2)(one failed and another died in diabetic group,one died in treat group2).After 72 hours,test blood sugar,those higher than 16.7mmol/L regard as succeed in diabetic models.Cordyceps sinensis (5.0mg/kg/d) are given by intragastric administration to teat group 1 from then on,and given group 2 after 4 weeks.While normal group and model group were given equivalent water.2.After 12 weeks, weights of the rats were measured, then they were sacrificed,and 24h urinary protein,blood sugar,blood serum creatinine,blood usea nitrogen were tested, and left kidney were weighted.After regular dehydration, paraffin imbedding, HE or PAS staining,the structure of the kidney were observed.3. Expression of t-PA,PAI-1, FN, COLâ…£in renal tissue were measured by Immunohistochemistry (ICH).4. Expression of t-PA,PAI-1 FN, COLâ…£mRNA were measured by real-time quantitative PCRResults1. General condition:compared with normal groups, the other groups appear polydipsia,polyphagia,polyuria, emaciated,fur matt, poor response. After treated by cordyceps sinensis, conditions were improved, and treat group 1 is better than treat group 2.After 12 weeks,the rat's weight in group M,treat group 1,treat group 2 were reduced significantly than group N (p<0.01).while the renal weight index of rats increased significantly betwwen group N and M (p<0.01),and reduced significantly between group M and treat group 1 (p<0.01),group M and treat group 2(p <0.05). 2. Biochemical indicator results:After 12 weeks,serum glucose, serum creatinine,24h urinary protein, blood usea nitrogen were all increased significantly(P<0.01)in group M, all of them were improved significantly in treat group 1 (P<0.01) except blood sugar and group 2: serum creatinine(P<0.05),24h urinary protein (P<0.01), blood usea nitrogen (P<0.01).All above indicators in treat group 1were improved better than treat group 2 (P<0.05) except blood sugar.3.Kidney pathyologic changes:in light microscope,HE and PAS shows:In group M,the glomeruli were large,mesangial area were expanded, appeared some nodositas sedimentum,broaden capillry membrane,distend or atrophy renal tubules,with monocyte,lymphocyte infiltrates. These pathologic changes were improved in treat groups, and treat group 1 was better than treat group 24.Immunohistochemistry results:t-PA, PAI-1 located in the renal tubular membranes mainly, while FN, Colâ…£located in the glomeruli,capillry membranes and Bowman's capsule chiefly. compared group M with group N, t-PA was reduced significantly (p<0.01),PAI-1, FN, COLâ…£were all increased significantly(p<0.01). compared treat group 1 with group M, t-PA was increased significantly (p<0.01), PAI-1 and Colâ…£were both reduced significantly (p<0.01), FN was reduced (p<0.05) compared treat group 2 with group M, t-PA was increased significantly (p <0.01), both PAI-1 and FN were reduced (p<0.05), Colâ…£was reduced (p<0.01).Compared treat group 1with treat group 2,the expression of PAI-1 and Colâ…£were reduced more (p<0.05)5. Real-time quantitative PCR shows:compared group M with group N, t-PA was reduced significantly (p<0.01),PAI-1, FN, COLâ…£were all increased significantly (p<0.01). compared treat group 1 with group M, t-PA was increased significantly (p<0.01), PAI-1 and Colâ…£were both reduced significantly (p<0.01), FN was reduced (p<0.05). compared treat group 2 with group M, t-PA was increased significantly (p<0.01), both PAI-1 and FN were reduced (p<0.05), Colâ…£was reduced (p< 0.01).Compared treat group 1 with treat group 2,the expression of PAI-1 and Colâ…£were reduced more(p<0.05).Results of RQ-PCR were coincide with ICH.6. Relevance analysis:In group M,t-PA has a negative relevance with Colâ…£(r=-0.614, P<0.05);PAI-1 has a positive relevance with both FN (r= 0.639, P<0.05) and Colâ…£(r=-0.586, P<0.05)Conclusions1. In DN rats'kidney,expression of t-PA was reduced significantly, PA I-1 was increased significantly, it suggests that in DN rats'kidney exists disorder of t-PA/PAI-1,and this disorder was closely related to the sedimentation of FN,Colâ…£,which were the main components of ECM t-PA has a negative relevance with Colâ…£; PAI-1 has a positive relevance with FN,Colâ…£.It suggests the disorder of t-PA/PAI-1 was one of the main reason of kidney fibrosis.2.After treated by cordyceps sinensis, the isorder of t-PA/PAI-1 was improved,the accumulation of FN,Colâ…£outside of glomerulus were reduced significantly,the 24h urinary protein and serum creatinine were reduced significantly.It suggests cordyceps sinensis can recover the balance of t-PA/PAI-1 to improve DN rats'kidney fibrosis and improve kidney function further.