Capsaicin, a pungent principle of hot red pepper, evokes catecholamine secretion from the adrenal medulla of anesthetized rats.
Using a direct monitoring system for catecholamine (CA) secretion into the adrenal vein, we have demonstrated that capsaicin (CAP) evokes CA secretion from the adrenal medulla of pentobarbital-anesthetized rats. A significant increase in epinephrine (E) secretion was seen in rats infused with CAP (200 micrograms/kg, i.v.) without a detectable lag after the infusion. Norepinephrine (NE) secretion evoked by CAP was fairly weak compared with E secretion. The secretion of E evoked by CAP was dose-amount dependent. The stimulation of E release by CAP was barely detectable at 20 micrograms/kg, half-maximal at 100 micrograms/kg, and maximal at 600 micrograms/kg. When CAP (200 micrograms/kg) was infused into rats, the weight-ratio of E to NE was significantly higher (47.6) than when acetylcholine (12.5 micrograms/kg) was infused (13.0). These results indicate that CAP can evoke CA secretion from the adrenal medulla of rats.
D000109:Acetylcholine / Q000494:pharmacology; D000313:Adrenal Medulla / Q000378:metabolism*; D000818:Animals; D002211:Capsaicin / Q000494:pharmacology*; D002395:Catecholamines / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D004837:Epinephrine / Q000378:metabolism; D009638:Norepinephrine / Q000378:metabolism; D051381:Rats; D012636:Secretory Rate / Q000187:drug effects; D013997:Time Factors
D002395:Catecholamines; D000109:Acetylcholine; D002211:Capsaicin; D009638:Norepinephrine; D004837:Epinephrine