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G L Kovacs

Publications and source records attributed to G L Kovacs.

10 recordsLinked to original sources
PubMed1992

Antipyretic effect of central arginine8-vasopressin treatment: V1 receptors specifically involved?

Intracerebroventricular (i.c.v.) administration of the neurohypophyseal neuropeptide arginine8-vasopressin (AVP) results in a dose-dependent attenuation of endotoxin-induced fever (EIF) in rats. Specific antagonists of the neuropeptided(CH2)5[Tyr(Me)2]AVP for V1 receptors, d(CH2)5[dlle2lle4]AVP for the V2 receptors and Des-Gly,NH2d(CH2)5[Tyr)Me2)Thr4Orn8]vasotocin, an antagonist of the oxytocin receptors (AOXT), failed to modify EIF when administered i.c.v. Relatively high doses (100 ng) of all three peptide antagonists effectively blocked the antipyretic effect of AVP. Administered in smaller doses (10 or 30 ng), however, a more specific interaction was observed, i.e. the V1 antagonist being the only effective compound in preventing the effect of AVP. Although the data indicate that peptide-antagonist interactions should be interpreted carefully, the present experiments confirm previous observations on the involvement of V1-type receptors in the antipyretic action of AVP and suggest additional interactions with V2 vasopressinergic and oxytocinergic receptors.

Animals↗
PubMed1983

Aldosterone blocks the response to corticosterone in the raphe-hippocampal serotonin system.

The accumulation of serotonin induced by the monoamino oxidase inhibitor pargyline was used as an index for 5-HT turnover in the dorsal hippocampus and raphe area. A low dose of corticosterone administered s.c. immediately after adrenalectomy significantly increased serotonin turnover in both regions over the subsequent 1 h interval. The same dose of aldosterone was ineffective, but pretreatment with aldosterone blocked the serotonin response to corticosterone in the acutely adrenalectomized rat. [3H]Corticosterone administered to adrenalectomized rats was not retained by cell nuclei of the raphe area in a limited capacity manner as occurred in the hippocampus. Pretreatment with aldosterone blocked the uptake of [3H]corticosterone in hippocampal cell nuclei. It is concluded that corticosterone triggers a serotonin response and that the specificity of the corticosterone action suggests involvement of the steroid receptor system located postsynaptically to the raphe-hippocampal serotonin projection.

Aldosterone↗