[Pharmacological studies on ginger. V. Pharmacological comparison between (6)-shogaol and capsaicin].
Pharmacological actions of (6)-shogaol and capsaicin were studied. Both (6)-shogaol (0.5 mg/kg, i.v.) and capsaicin (0.1 mg/kg, i.v.) caused a triad such as a rapid fall in blood pressure, bradycardia and aponea in rats. Both drugs-induced marked pressor responses in blood pressure, which occurred after the rapid fall, were markedly reduced by a spinal destruction. In pithed rats, both drugs-induced peripheral pressor responses were markedly reduced with the combined treatment of [D-Arg1, D-Pro2, D-Trp7,9, Leu11]-substance P (0.5 mg/kg, i.v.), phentolamine (10 mg/kg, i.v.) and the section of sciatic nerves. In isolated guinea-pig trachea, (6)-shogaol (100 microM) and capsaicin (10 microM) induced contractile responses which were slightly inhibited by substance P antagonist (10 microM), but exhibited also a tachyphylaxis. Furthermore, although (6)-shogaol (3.6 microM) showed positive inotropic and chronotropic actions on isolated atria in rats, this effect of (6)-shogaol disappeared by repeated injections or pretreatment (100 mg/kg, s.c.) of (6)-shogaol. These results suggest that (6)-shogaol and capsaicin have similar actions, and that both drugs may cause a peripheral action by releasing an unknown active substance from nerve ends.
D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D002211:Capsaicin / Q000494:pharmacology*; D002396:Catechols / Q000494:pharmacology*; D004347:Drug Interactions; D006168:Guinea Pigs; D006321:Heart / Q000187:drug effects; D066298:In Vitro Techniques; D008297:Male; D051379:Mice; D009130:Muscle, Smooth / Q000187:drug effects; D051381:Rats; D011919:Rats, Inbred Strains; D012119:Respiration / Q000187:drug effects; D013618:Tachyphylaxis; D014132:Trachea
D002396:Catechols; C040115:shogaol; D002211:Capsaicin