Dexamethasone sensitizes soluble guanylate cyclase in the rat renal glomeruli.
We measured capability for guanosine 3',5'-cyclic monophosphate (cGMP) synthesis by isolated renal glomeruli from steroid-treated rats. Glomeruli obtained from animals treated with dexamethasone showed 5-fold higher sensitivity to sodium nitroprusside (SNP) than glomeruli from deoxycorticosterone- or saline-treated rats. Similar increase in activity of the glomerular soluble guanylate cyclase in response to SNP was observed. Dexamethasone markedly suppressed stimulatory effect of atrial natriuretic factor (ANF) on glomerular cGMP synthesis suggesting existence of cross-regulatory system(s) generating cGMP in renal glomeruli. We presume that glucocorticoid-induced hyperfiltration can be partially caused by sensitization of soluble guanylate cyclase to the nitric oxide, a potent natural dilatory agent.
Lewko
B
B
Department of Clinical Biochemistry, Medical Academy, Gdansk, Poland.
Wendt
U
U
Stepinski
J
J
Angielski
S
S
D015056:1-Methyl-3-isobutylxanthine / Q000494:pharmacology; D000818:Animals; D006152:Cyclic GMP / Q000378:metabolism; D003600:Cytosol / Q000201:enzymology; D003900:Desoxycorticosterone / Q000494:pharmacology*; D003907:Dexamethasone / Q000494:pharmacology*; D006162:Guanylate Cyclase / Q000378:metabolism*; D007678:Kidney Glomerulus / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D007700:Kinetics; D007770:L-Lactate Dehydrogenase / Q000032:analysis; D008297:Male; D009599:Nitroprusside / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D012016:Reference Values
D009599:Nitroprusside; D003900:Desoxycorticosterone; D003907:Dexamethasone; D007770:L-Lactate Dehydrogenase; D006162:Guanylate Cyclase; D006152:Cyclic GMP; D015056:1-Methyl-3-isobutylxanthine