Hypothalamic heating and cooling in monoamine-depleted rabbits.
The role of monoamines in the thermoregulatory responses induced by hypothalamic heating and cooling was investigated in conscious rabbits. Depletion of hypothalamic catecholamines by pretreatment with 6-hydroxydopamine (6-OHDA) greatly attenuated the rectal temperature and vasomotor responses to hypothalamic heating and cooling. Pretreatment with p-chlorophenylalanine (PCPA) depleted the animals of 5-hydroxytryptamine (5-HT). The results obtained are consistent with 5-HT having an inhibitory role in the rabbit's vasomotor response to heat stress and activating heat conservation during cold stress. Reserpinized rabbit were depleted of both norepinephrine (NE) and 5-HT and were found to be unresponsive to hypothalamic temperature changes. We conclude that the integrity of the monoaminergic system is viral for the correct functioning of the hypothalamus in maintaining a constant body temperature.
D000818:Animals; D001831:Body Temperature; D001833:Body Temperature Regulation / Q000187:drug effects; D003080:Cold Temperature; D010134:Fenclonine / Q000494:pharmacology; D006358:Hot Temperature; D006892:Hydroxydopamines / Q000494:pharmacology; D007031:Hypothalamus / Q000502:physiology*; D009638:Norepinephrine / Q000502:physiology*; D011817:Rabbits / Q000502:physiology*; D011941:Receptors, Adrenergic; D012110:Reserpine / Q000494:pharmacology; D012701:Serotonin / Q000502:physiology*
D006892:Hydroxydopamines; D011941:Receptors, Adrenergic; D012701:Serotonin; D012110:Reserpine; D010134:Fenclonine; D009638:Norepinephrine