title: Opposing actions of dibutyryl cyclic AMP and GMP on temperature in conscious guinea-pigs.
abstract: Intracerebroventricular administration of dibutyryl cyclic AMP (Db-cAMP), induced hyperthermia in guinea-pigs which was not mediated through prostaglandins (PG) or norepinephrine since a prostaglandin synthesis inhibitor, indomethacin, and an alpha-adrenergic receptor blocking agent, phenoxybenzamine did not antagonize the hyperthermia. In contrast, the hyperthermic response to dibutyryl cyclic AMP was attenuated by central administration of a beta-adrenergic receptor antagonist, sotalol, indicating that cyclic AMP may be involved, through beta-adrenergic receptors, in the central regulation of heat production/conservation. Central administration of dibutyryl cyclic GMP (Db-cGMP) produced hypothermia which was not mediated via histamine H1- or H2-receptors and serotonin since the H1-receptor antagonist, mepyramine, the H2-receptor antagonist, cimetidine, and the serotonin antagonist, methysergide, had no antagonistic effects. The antagonism of hypothermia induced by dibutyryl cyclic GMP and acetylcholine + physostigmine, by central administration of a cholinergic muscarinic receptor antagonist, atropine, and not by a cholinergic nicotinic receptor antagonist, d-tubocurarine, suggests that cholinoceptive neurons and endogenous cyclic GMP may regulate heat loss through cholinergic muscarinic receptors. These results support a regulatory role in thermoregulation provided by a balance between opposing actions of cyclic AMP and cyclic GMP in guinea-pigs.
mesh_terms: D000818:Animals; D001831:Body Temperature / Q000187:drug effects*; D003994:Bucladesine / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D000242:Cyclic AMP / Q000502:physiology; D006152:Cyclic GMP / Q000031:analogs & derivatives* / Q000502:physiology; D003995:Dibutyryl Cyclic GMP / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D006168:Guinea Pigs; D006632:Histamine / Q000502:physiology; D007276:Injections, Intraventricular; D008297:Male; D009638:Norepinephrine / Q000502:physiology; D011453:Prostaglandins / Q000502:physiology; D012701:Serotonin / Q000502:physiology
chemical_list: D011453:Prostaglandins; D003995:Dibutyryl Cyclic GMP; D012701:Serotonin; D003994:Bucladesine; D006632:Histamine; D000242:Cyclic AMP; D006152:Cyclic GMP; D009638:Norepinephrine