Micropuncture and morphometric studied will relate glomerular function and structure in rats with experimental type I diabetes, insulin resistance without hyperglycemia, and type II diabetes.
The first aim i s to relate glomerular function to epithelial cell structure in experimental type I diabetes. Recent morphologic studies suggest that hyperfiltration in patients with early type I diabetes is accompanied by a remarkable increase in the width of epithelial cell foot processes. Proposed studies will test the hypothesis that widening of epithelial cell foot processes accounts for the observation that the glomerular ultrafiltration coefficient (Kf) remains normal while peripheral capillary surface area increases in type I diabetes. These studies will further determine whether the increases in Kf which accompany insulin administration and converting enzyme inhibitor therapy are associated with a reduction in foot process width toward normal.
The second aim i s to identify factors responsible for glomerular injury in the setting of insulin resistance without overt hyperglycemia. Proposed studies will be carried out in rats made insulin resistant by fructose feeding. Like insulin resistant humans, these animals develop both hypertension and hyperlipidemia, and have further been shown to develop accelerated glomerulosclerosis. Proposed studies will establish whether drugs which reduce blood pressure and plasma lipid levels retard the development of glomerular injury in this model.
The third aim i s to identify factors responsible for glomerular injury in type a rat model of type II diabetes in which hyperglycemia is associated with experimental type II diabetes is characterized by glomerular hypertrophy and hyperfiltration. Long-term studies will establish whether drugs which reduce blood pressure and plasma lipid levels also retard the development of glomerular injury in this diseases model. The ultimate goal of these studies is to provide a rational basis for treatment aimed at limiting glomerular injury in diabetes mellitus.

Agency
National Institute of Health (NIH)
Institute
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Type
Research Project (R01)
Project #
5R01DK042093-03
Application #
3243092
Study Section
General Medicine B Study Section (GMB)
Project Start
1990-03-01
Project End
1993-12-31
Budget Start
1992-03-01
Budget End
1993-12-31
Support Year
3
Fiscal Year
1992
Total Cost
Indirect Cost
Name
Stanford University
Department
Type
Schools of Medicine
DUNS #
800771545
City
Stanford
State
CA
Country
United States
Zip Code
94305
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Park, S K; Meyer, T W (1995) The effect of hyperglycemia on glomerular function in obese Zucker rats. J Lab Clin Med 125:501-7
McDermott, A M; Sharp, G W (1995) Gi2 and Gi3 proteins mediate the inhibition of adenylyl cyclase by galanin in the RINm5F cell. Diabetes 44:453-9
Gillison, S L; Sharp, G W (1994) ADP ribosylation by cholera toxin identifies three G-proteins that are activated by the galanin receptor. Studies with RINm5F cell membranes. Diabetes 43:24-32
Mayer, G; Lafayette, R A; Oliver, J et al. (1993) Effects of angiotensin II receptor blockade on remnant glomerular permselectivity. Kidney Int 43:346-53
Lafayette, R A; Mayer, G; Meyer, T W (1993) The effects of blood pressure reduction on cyclosporine nephrotoxicity in the rat. J Am Soc Nephrol 3:1892-9
Lafayette, R A; Mayer, G; Park, S K et al. (1992) Angiotensin II receptor blockade limits glomerular injury in rats with reduced renal mass. J Clin Invest 90:766-71
Park, S K; Meyer, T W (1992) The effects of fructose feeding on glomerular structure in the rat. J Am Soc Nephrol 3:1330-2
Meyer, T W (1991) Glomerular hemodynamic function in early diabetes. J Diabet Complications 5:53-5