Perfusions of the posterior hypothalamus of cats with various ions and saccharides: effects on body temperature.
Alterations of the ionic constituents of solutions perfused through the tissue of the posterior hypothalamic region in conscious cats elicited changes in body temperatures. Increasing the (Ca2+) to (Na+) ratio of the perfusion solution elicited falls in body temperature which were accompanied by changes in posture and vasomotor tone which assisted the heat loss. The magnitude of the fall was dependent on the ratio of (Ca2+) to (Na+) and was not related to the osmolarity of perfusion solution. The addition of dextrose to the perfusion solution attenuated or abolished the response produced by an increase in the (Ca2+) to (Na+) ratio. This dextrose effect could be attributed to its role as an energy substrate. These data are consistent with and extend previous suggestions that the set point for body temperature may be dependent on the inherent ratio of the ionic constituents of the posterior hypothalamic area. Further, they suggest that these ionically induced alterations can be overriden by increasing the available energy substrate.
D000818:Animals; D001831:Body Temperature / Q000187:drug effects*; D002241:Carbohydrates / Q000494:pharmacology*; D002415:Cats; D007031:Hypothalamus / Q000187:drug effects*; D007034:Hypothalamus, Posterior / Q000187:drug effects*; D007477:Ions / Q000494:pharmacology*; D010477:Perfusion; D013997:Time Factors
D002241:Carbohydrates; D007477:Ions