Centrally administered neuropeptide Y enhances the hypothermia induced by peripheral administration of adrenoceptor antagonists.
The distribution of neuropeptide Y in the brain includes extensive coexistence within adrenaline- and noradrenaline-containing neurons and many of its actions are often associated with adrenergic systems. Since neuropeptide Y immunoreactivity is particularly intense in the preoptic area, one of the principal sites for thermoregulation, we have tested the effects of neuropeptide Y on core temperature in normothermic rats, and rats rendered hypothermic by systemic treatment with adrenergic antagonists. In the normothermic rat, intracerebroventricular administration of 1 microgram of neuropeptide Y did not have a significant effect on core temperature. Intraperitoneal treatment with the alpha 1-adrenoceptor antagonist, prazosin, or the beta-adrenoceptor antagonist, propranolol, caused an immediate and significant hypothermia; the intracerebroventricular administration of 1 microgram of neuropeptide Y, 10 minutes after these drugs, strongly potentiated their hypothermic effect. Although intraperitoneal treatment with the alpha 2-adrenoceptor antagonist, idazoxan, had no hypothermic effect per se, the intracerebroventricular administration of NPY 10 minutes after this antagonist led to a significant decrease in core temperature.
Ruiz de Elvira
M C
MC
Division of Biomedical Sciences, King's College, University of London.
Coen
C W
CW
D000316:Adrenergic alpha-Agonists / Q000008:administration & dosage / Q000494:pharmacology*; D000319:Adrenergic beta-Antagonists / Q000008:administration & dosage / Q000494:pharmacology*; D000818:Animals; D001833:Body Temperature Regulation / Q000187:drug effects*; D004146:Dioxanes / Q000494:pharmacology; D004357:Drug Synergism; D005260:Female; D007035:Hypothermia / Q000139:chemically induced*; D019329:Idazoxan; D007274:Injections, Intraperitoneal; D007276:Injections, Intraventricular; D009478:Neuropeptide Y / Q000008:administration & dosage / Q000494:pharmacology* / Q000633:toxicity; D011224:Prazosin / Q000494:pharmacology / Q000633:toxicity; D011433:Propranolol / Q000494:pharmacology / Q000633:toxicity; D051381:Rats; D011919:Rats, Inbred Strains
D000316:Adrenergic alpha-Agonists; D000319:Adrenergic beta-Antagonists; D004146:Dioxanes; D009478:Neuropeptide Y; D011433:Propranolol; D011224:Prazosin; D019329:Idazoxan