It has been suggested that @entity11184 ( @entity11184 ) is an endogenous modulator of cardiovascular systems. We have reported that @entity11184 (1-34), but not PTH(1-34), causes the release of @entity369 -vasopressin (AVP) from the supraoptic nucleus (SON) of the hypothalamus in vitro through a novel receptor distinct from the PTH/ @entity11184 receptors (type I or type II) described previously. In this study, we have investigated the in vivo effects of @entity11184 (1-34) on AVP secretion and its, messenger RNA (mRNA) expression in the SON in conscious @entity35 . Intracerebroventricular (i.c.v.) administration of @entity11184 (1-34) resulted in an increase in plasma @entity1831 concentration in a dose-dependent manner (0-400 pmol/ @entity35 ). The maximal effect was obtained at 15 min after i.c.v. administration of @entity11184 (1-34). Neither @entity11184 (7-34) nor PTH(1-34) had any effect on plasma AVP levels. @entity11184 (1-34)-induced AVP secretion was antagonized by pretreatment with @entity11184 (7-34) but not by that with PTH(1-34). In addition, in situ hybridization study revealed that AVP mRNA expression in the SON and paraventricular nucleus was significantly increased 30 min after i.c.v. administration of @entity11184 (1-34) and reached a maximum at 180 min. Furthermore, in Northern blot analyses, AVP mRNA expression in the SON was increased to approximately a 2-fold of basal level by @entity11184 (1-34). On the other hand, neither @entity11184 (7-34) or PTH(1-34) had any effect on the mRNA expression. The @entity11184 (1-34)-stimulated AVP mRNA expression was eliminated by pretreatment with @entity11184 (7-34) but not with PTH(1-34). These results suggest that, in the central nervous system, @entity11184 (1-34) is involved in AVP secretion through a novel receptor distinct from the PTH/ @entity11184 receptors reported previously, playing a role in the body water and electrolyte homeostasis.

Centrally administered parathyroid hormone (PTH)-related protein(1-34) but not PTH(1-34) stimulates @entity369 -vasopressin secretion and its messenger ribonucleic acid expression in supraoptic nucleus of the conscious XXXX .

@entity35 :: ('10116', 'Species') :: ['rat', 'rats'] @entity1831 :: ('CHEBI:34543', 'Chemical') :: ['AVP'] @entity11184 :: ('24695(Tax:10116)', 'Gene') :: ['PTH-related protein', 'PTHrP'] @entity369 :: ('CHEBI:29016', 'Chemical') :: ['arginine']
@entity35 :: (10116,Species) :: ['rats']
