Abstract

DIAZ, E  and  ISRAEL, A. Papel de los receptores de la Adrenomedulina y del Péptido relacionado con el Gen de la Calcitonina en la acción renal de la adrenomedulina administrada centralmente. AVFT [online]. 2002, vol.21, n.1, pp.58-64. ISSN 0798-0264.

To determine pharmacological specificity of intracerebroventricular (IVT) administration of adrenomedullin (AM) on water and sodium excretion, studies were performed in rats pretreated with AM(22-52), a putative AM-receptor antagonist or CGRP(8-37), a ligand that preferentially antagonizes the CGRP₁-receptor subtype. In addition, the effects of IVT injection of calcitonin-gene-related-peptide (CGRP) on urinary water and electrolyte excretion was assessed. Intracerebroventricular administration of rat adrenomedullin to conscious hydrated rats, resulted in a significant increase in urinary volume and sodium excretion during the 6-hour period of urine collection and was most effective during the 3 and 6 hrs. Although less effective than AM, central administration of CGRP induced diuresis and natriuresis. Pretreatment with AM(22-52) or CGRP(8-37) significantly suppressed the diuretic and natriuretic effect of IVT-AM. These data suggest that both, CGRP₁ and AM receptors, are involved in the centrally mediated diuretic and natriuretic action of the AM. Our results provide evidence supporting the hypothesis that endogenous AM plays a role in the central nervous control of fluid and electrolyte homeostasis.

Keywords : Sodium excretion; Adrenomedullin; Calcitonin gene-related peptide.