de Arruda Camargo GM, de Arruda Camargo LA, Saad WA
Medial septal area vasopressin receptor subtypes in the regulation of urine and sodium excretion in rats. [JOURNAL ARTICLE]
J Neuroendocrinol 2008 Dec 6.
Abstract The present study was intended to determine the effects of selective antagonists of V(1a), V(2), and V(1a)/V(2) (Conivaptan) arginine(8)-vasopressin (AVP) receptors on the flow of urine and sodium excretion induced by AVP, by means of microinjections into the medial septal area (MSA) of the rat brain. Male Holtzman rats had a guide cannula implanted into the dorsal surface of the MSA. Intravenous infusion of hypotonic saline was used to promote urinary flow, which was collected for 4h. Pretreatment with the V(1a) antagonist decreased, whereas the V(2) antagonist and Conivaptan (a V(1a)/V(2) antagonist) increased, the urinary flow induced by AVP. Administration of AVP increased sodium excretion. Pretreatment with V(2) or V(1a) antagonists decreased, whereas Conivaptan abolished, the sodium excretion induced by AVP. These results indicate that the V(1a) and V(2) receptors of the MSA are important in the central regulation of urine and sodium excretion.
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