Receptors for atrial natriuretic peptide are decreased in the kidney of rats with streptozotocin-induced diabetes mellitus.
AUTOR(ES)
Sechi, L A
RESUMO
To determine whether decreased renal responsiveness to atrial natriuretic peptide (ANP) in diabetes is mediated by alterations in the renal ANP receptor, ANP receptor density and affinity were measured 17-20 d after streptozotocin injection and compared with values in vehicle-treated controls and streptozotocin-treated rats made euglycemic with insulin. Plasma ANP concentration was significantly greater in hyperglycemic diabetic rats than in control or euglycemic diabetic rats. Both in glomeruli and inner medulla, ANP receptor dissociation constant did not differ among the three study groups, whereas the maximum binding capacity was decreased significantly in hyperglycemic diabetics in comparison with controls and euglycemic diabetics. Glomerular clearance receptors were also decreased significantly in hyperglycemic diabetic rats in comparison with control and euglycemic diabetic rats. To determine whether the decreased number of renal ANP receptors in diabetic rats was associated with a decreased biological response, we measured ANP-dependent cyclic GMP (cGMP) accumulation by isolated glomeruli and inner medullary collecting duct cells in vitro. cGMP accumulation was significantly less in hyperglycemic diabetic rats than in controls or euglycemic diabetic rats both in the presence or absence of the phosphodiesterase inhibitor zaprinast. cGMP phosphodiesterase activity in inner medullary collecting duct cells obtained from control and hyperglycemic diabetic rats did not differ. Thus, the decreased number of biologically active ANP receptors in the kidneys of diabetic rats is accompanied by decreased biological responsiveness in vitro and provides a potential explanation for the reduction in renal sensitivity to ANP in this condition.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=295920Documentos Relacionados
- Increased prostaglandin production by glomeruli isolated from rats with streptozotocin-induced diabetes mellitus.
- A role for glycosphingolipid accumulation in the renal hypertrophy of streptozotocin-induced diabetes mellitus.
- Glucagon-stimulable adenylyl cyclase in rat liver. The impact of streptozotocin-induced diabetes mellitus.
- Serum lipoproteins and apolipoproteins in rats with streptozotocin-induced diabetes.
- Subhuman Primate Pregnancy Complicated by Streptozotocin-Induced Diabetes Mellitus