Cyclic GMP excretion blocked by isatin administration under conditions of fluid overload.
Isatin is a potent inhibitor of atrial natriuretic peptide (ANP) receptors and ANP-induced generation of cGMP in vitro. This study was designed to determine whether it had a similar effect in vivo, using a model of fluid overload known to induce ANP. We confirmed that this model increased urinary output of cGMP 3 hr after volume loading, and showed that this effect was blocked by i.p. injection of isatin (50 mg/kg). Isatin had no effect on urine volume or sodium output. However, isatin did have an effect on plasma protein concentration, both compared with control values, compatible with shifting fluid to the vascular compartment, and after volume overload, in which it normalised such a shift. Isatin thus affected both the generation of cGMP and fluid balance in vivo.
Medvedev
A
A
Institute of Biomedical Chemistry, Russian Academy of Medical Sciences, Moscow, Russia.
Adamik
A
A
Glover
V
V
Telegdy
G
G
D000704:Analysis of Variance; D000818:Animals; D001798:Blood Proteins / Q000187:drug effects / Q000378:metabolism; D001826:Body Fluids / Q000378:metabolism; D006152:Cyclic GMP / Q000097:blood*; D007510:Isatin / Q000494:pharmacology*; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D012964:Sodium / Q000378:metabolism
D001798:Blood Proteins; D007510:Isatin; D012964:Sodium; D006152:Cyclic GMP