Altered regulation of renin secretion by insulinlike growth factors and angiotensin II in diabetic rats
Altered regulation of renin secretion by insulinlike growth factors and angiotensin II in diabetic rats. E Jost-Vu , R Horton and I Antonipillai University of Southern California Medical Center, Division of Endocrinology, Los Angeles 90033. Abstract The etiology of the low renin state in DM is not c...
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Published in | Diabetes (New York, N.Y.) Vol. 41; no. 9; pp. 1100 - 1105 |
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Main Authors | , , |
Format | Journal Article |
Language | English |
Published |
American Diabetes Association
01.09.1992
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Online Access | Get full text |
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Summary: | Altered regulation of renin secretion by insulinlike growth factors and angiotensin II in diabetic rats.
E Jost-Vu ,
R Horton and
I Antonipillai
University of Southern California Medical Center, Division of Endocrinology, Los Angeles 90033.
Abstract
The etiology of the low renin state in DM is not clear. To assess the role of certain growth and regulatory factors in this
process, we studied the effects of insulin, IGF-I, and IGF-II on the renin-angiotensin system in normal and 8-wk STZ-induced
diabetic rats. Renin secretion was studied both in static incubations and by perifusion of rat renal cortical slices. In diabetic
rats, both plasma renin activity (0.65 +/- 1.6 vs. 4.0 +/- 1.2 ng ANG I.ml-1.h-1) and tissue renin concentrations (27 +/-
5 vs. 51 +/- 8 ng ANG I.mg tissue-1.h-1) were reduced. Insulin (0.1-1.0 mu/ml) and IGF-I (10(-9) to 4 x 10(-9) M) stimulated
renin secretion in normal tissue (control, 95 +/- 3%; insulin [0.5 mu/ml], 134 +/- 7%; IGF-I [4 x 10(-9) M], 149 +/- 7%).
IGF-I stimulated renin secretion in perifusions as early as 30 min, whereas IGF-II had no effect. However, in diabetic renal
tissue, neither insulin (0.1-1.0 mu/ml) nor IGF-I (10(-9) to 4 x 10(-9) M) had an effect on renin. This lack of effect was
overcome by adding up to 100-fold higher concentrations of these growth factors. ANG II (10(-10) M-10(-8) M) had an exaggerated
inhibitory effect on renin secretion in diabetic tissue. This study suggests that the low renin state in DM may be explained
by the enhanced inhibitory effect of ANG II and the resistance to the secretogogue actions of insulin and IGF-I. |
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ISSN: | 0012-1797 1939-327X 0012-1797 |
DOI: | 10.2337/diabetes.41.9.1100 |