Inhibition of XXXX and OT release by water in @entity3485 is independent of opioid peptides.

@entity398 @entity548 @entity5225 @entity1510 @entity3485 @entity112 @entity35 @entity6659 @entity970 @entity968
@entity5225 inhibits release of @entity6659 ( @entity6659 ) and @entity398 (OT) from the hypothalamo-neurohypophysial system during @entity3485 . We investigated whether opioid peptides mediate the inhibitory effect of water on secretion of these hormones. Conscious male @entity35 were made @entity3485 by @entity548 ( @entity548 , 0.51 ml/min) of 20 and 35% of the blood volume or by injection of either subcutaneous @entity968 ( @entity970 , 20,000 mol wt, 35 ml/kg) or intraperitoneal @entity112 (HIS, 15 mg/kg, 1 ml/kg). Animals were intubated orally 1-4 min ( @entity548 , HIS) or 6.75 h ( @entity970 ) later with or without administration of water (40 ml/kg). Four to seven min after intubation @entity35 were injected with saline (1 ml/kg) or @entity1510 (2 or 5 mg/kg) and then decapitated 6-10 min later. Control animals were treated similarly but were not stimulated by @entity3485 . @entity6659 and OT were extracted from plasma and quantified by radioimmunoassay. Data were analyzed by analysis of variance. In @entity548 animals blood pressure fell and plasma osmolality increased, both of which correlated positively with the rise in plasma [ @entity6659 ] and [OT]. @entity5225 lowered the plasma osmolality, attenuated the fall in blood pressure, and reduced [ @entity6659 ] and [OT] in plasma of @entity548 animals. The opiate receptor antagonist, @entity1510 , did not alter these changes in blood pressure or plasma osmolality, or the plasma [ @entity6659 ] after @entity548 in @entity35 treated with or without water. Plasma [OT] was, however, increased by @entity1510 in both normally hydrated and overhydrated @entity35 . Thus, regardless of the hydrational state of the animal, opioid peptides inhibited release of OT but not @entity6659 during @entity548 . Data consistent with this interpretation were also obtained from @entity35 made @entity3485 with @entity970 or HIS.(ABSTRACT TRUNCATED AT 250 WORDS)
