The effect of amiloride and sodium chloride on rat renal and hepatic 11 beta-hydroxysteroid dehydrogenase activities.
The ability of glucocorticoid hormones to interact with glucocorticoid or mineralocorticoid receptors is modulated by 11 beta-hydroxysteroid dehydrogenases, interconverting active 11 beta-hydroxyglucocorticoids to inactive 11-ketones. This is, amongst others, important in maintaining a normal salt-water homeostasis. In this study, we determined the effect of treating rats for 4 days with the potassium sparing diuretic amiloride (5 mg/kg subcutaneously) or with 3% NaCl in drinking water on renal and hepatic microsomal oxidative and reductive 11 beta-hydroxysteroid dehydrogenase activities and immunoreactive 11 beta-hydroxysteroid dehydrogenase 1 protein. Treatment with amiloride resulted in a 1.5-fold rise of microsomal corticosterone 11 beta-oxidation rates in kidney (using NAD and NADP as cofactors) and in liver (for NADP only), but had no effect on microsomal 11-dehydrocorticosterone reduction. Renal 11 beta-hydroxysteroid dehydrogenase 1 immunoreactive protein was increased 1.6-fold by amiloride. NaCl treatment appeared to have no effect.
Niepel
T
T
Department of Microbiology, German Society for Biotechnological Research (GBF), Braunschweig, Germany.
Maser
E
E
Hermans
J J
JJ
D042842:11-beta-Hydroxysteroid Dehydrogenases; D000284:Administration, Oral; D000584:Amiloride / Q000633:toxicity*; D000704:Analysis of Variance; D000818:Animals; D004232:Diuretics / Q000008:administration & dosage / Q000633:toxicity*; D004326:Drinking; D006913:Hydroxysteroid Dehydrogenases / Q000378:metabolism*; D007279:Injections, Subcutaneous; D007668:Kidney / Q000187:drug effects* / Q000201:enzymology; D008297:Male; D008861:Microsomes / Q000187:drug effects* / Q000201:enzymology; D008862:Microsomes, Liver / Q000187:drug effects* / Q000201:enzymology; D010084:Oxidation-Reduction; D011485:Protein Binding / Q000187:drug effects; D051381:Rats; D017208:Rats, Wistar; D012965:Sodium Chloride / Q000008:administration & dosage / Q000633:toxicity*
D004232:Diuretics; D012965:Sodium Chloride; D000584:Amiloride; D006913:Hydroxysteroid Dehydrogenases; D042842:11-beta-Hydroxysteroid Dehydrogenases