Further evidence that a beta-adrenergic mechanism regulates water intake: role of the subfornical organ.
The daily water intake was reduced in rats by subcutaneous administration of propranolol. The fluid intake after 24 h of dehydration in nephrectomized animals was decreased by propranolol. In intact rats diazepam did not modify the postdehydration water intake. Propranolol injected into subfornical organ decreased water consumption after 24 h of fluid deprivation but did not change the dipsogenic response to carbachol given in the same structure. These results suggest that a beta-adrenoceptor mechanism participates in the regulation of the daily water intake. After a stimulus such as dehydration, beta-blockade modifies water consumption by a non-renal mechanism. This mechanism involves neither a general depressant nervous activity nor a local anesthetic action and could be located in a periventricular structure, the subfornical organ.
D000818:Animals; D002217:Carbachol / Q000494:pharmacology; D003681:Dehydration; D003975:Diazepam / Q000494:pharmacology; D004327:Drinking Behavior / Q000187:drug effects / Q000502:physiology*; D009392:Nephrectomy; D009490:Neurosecretory Systems / Q000502:physiology*; D011433:Propranolol / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D011943:Receptors, Adrenergic, beta / Q000502:physiology*; D013356:Subfornical Organ / Q000502:physiology*
D011943:Receptors, Adrenergic, beta; D002217:Carbachol; D011433:Propranolol; D003975:Diazepam