[Expression of type I transforming growth factor beta receptor in renal cortex in streptozotocin-induced diabetic rats and the regulation of benazepril].
OBJECTIVE
To study the expression of type I transforming growth factor beta receptor (TGFbetaRI) in renal cortex in streptozotocin-induced diabetic rats and the regulation of benazepril.


METHODS
The rats were randomized to following groups: uninephrectomized rats (group C), streptozotocin diabetic rats (group D) and diabetic rats treated with benazepril (group DB). Blood glucose, serum creatinine, body weight, kidney weight and renal protein content as well as angiotensin-convertion enzyme (ACE) activity of plasma, and renal cortex and medulla were observed after 4 weeks of treatment. The expressions of TGFbetaR I mRNA, 1alpha (IV) precollagen, fibronectin (FN) mRNA and TGFbetaR I protein were measured by reverse transcription-polymerase chain reaction (RT-PCR), Northern blot and Western blot, respectively.


RESULTS
Group DB had hyperglycemia, body weight loss, kidney hypertrophy and increased ACE activity in renal cortex despite a decrease in plasma ACE activity. These changes were associated with 1.12, 4.25, 1.50 and 1.10 fold increase in TGFbetaR I, 1alpha (IV) collagen, FN mRNA and TGFbetaR I protein expressions during a 4 week time course; Administration of benazepril could attenuate hyperglycemia, body weight loss and kidney hypertrophy, ACE activity in plasma and cortex was decreased by 92.00% and 88.77%, respectively, It also could reduce TGFbetaR I, 1alpha (IV) collagen, FN mRNA and TGFbetaR I protein by 63.89%, 61.90%, 45.83%, 52.13%, respectively.


CONCLUSIONS
It is suggested that there is an interaction between TGFbetaR I and the pathogenesis of diabetic nephropathy. Benazepril can supress the expression of TGFbetaR I in renal cortex.
Wu
Y
Y
Division of Nephrology, Huashan Hospital, Shanghai Medical University, Shanghai 200040.
Lin
S
S
D000806:Angiotensin-Converting Enzyme Inhibitors / Q000494:pharmacology*; D000818:Animals; D001552:Benzazepines / Q000494:pharmacology*; D024141:Collagen Type IV / Q000235:genetics / Q000378:metabolism; D003921:Diabetes Mellitus, Experimental / Q000378:metabolism*; D005353:Fibronectins / Q000235:genetics / Q000378:metabolism; D007672:Kidney Cortex / Q000378:metabolism; D008297:Male; D012333:RNA, Messenger / Q000235:genetics; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar; D018125:Receptors, Transforming Growth Factor beta / Q000235:genetics / Q000378:metabolism*
D000806:Angiotensin-Converting Enzyme Inhibitors; D001552:Benzazepines; D024141:Collagen Type IV; D005353:Fibronectins; D012333:RNA, Messenger; D018125:Receptors, Transforming Growth Factor beta; C044946:benazepril