Capsaicin-, resiniferatoxin-, and olvanil-induced adrenaline secretions in rats via the vanilloid receptor.
The effects of capsaicin analogs on adrenaline secretion were investigated in rats. Capsaicin (20-100 microg/kg, i.v.) caused biphasic adrenaline secretion. Capsazepine (20 mg/kg, i.v.), a specific competitive antagonist of the vanilloid (capsaicin) receptor, strongly inhibited both phases of adrenaline secretion by capsaicin (50 microg/kg). Next, the effects of two capsaicin analogs on the adrenal catecholamine secretion were examined. Resiniferatoxin (20-200 ng/kg, i.v.), a naturally occurring phorbolester-like compound, provoked slow onset adrenaline secretion in a dose-dependent manner. Olvanil (2.46-246 microg/kg, i.v.), a synthesized non pungent capsaicin analog, also stimulated delayed catecholamine secretion dose-dependently. Capsazepine (20 mg/kg, i.v.) pretreatment prevented the resiniferatoxin (50 ng/kg)- and olvanil (24.6 microg/kg)-induced catecholamine secretion. These results suggest that some vanilloids (capsaicin, resiniferatoxin, olvanil) excite adrenaline secretion and such excitation is via the vanilloid receptor.
Watanabe
T
T
School of Food and Nutritional Sciences, University of Shizuoka, Japan. watanbt@u-shizuoka-ken.ac.jp
Sakurada
N
N
Kobata
K
K
D000311:Adrenal Glands / Q000187:drug effects / Q000378:metabolism; D000818:Animals; D002211:Capsaicin / Q000031:analogs & derivatives* / Q000494:pharmacology*; D004224:Diterpenes / Q000494:pharmacology*; D004837:Epinephrine / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D011955:Receptors, Drug / Q000187:drug effects* / Q000502:physiology*
D004224:Diterpenes; D011955:Receptors, Drug; C054256:olvanil; C024353:resiniferatoxin; C071423:capsazepine; D002211:Capsaicin; D004837:Epinephrine