Field-stimulus response of guinea-pig atria as influenced by the peptides angiotensin, bradykinin, and substance P.
Field stimulation produced in isolated guinea-pig left atria a positive inotropic response, which was highly sensitive to the inhibitory actions of lidocaine, tetrodotoxin, and of pindolol. The field-stimulus effect was enhanced by angiotensin and by bradykinin, but not by substance P. Only bradykinin exerted also a direct positive inotropic effect (in the absence of field stimulation). It is concluded that the intramural adrenergic neurons of the guinea-pig atrium have receptors for both angiotensin and bradykinin, but not for substance P.
D000804:Angiotensin II / Q000494:pharmacology*; D000818:Animals; D001920:Bradykinin / Q000494:pharmacology*; D004558:Electric Stimulation; D006168:Guinea Pigs; D006321:Heart / Q000187:drug effects*; D066298:In Vitro Techniques; D008012:Lidocaine / Q000494:pharmacology; D008297:Male; D010869:Pindolol / Q000494:pharmacology; D013373:Substance P / Q000494:pharmacology*; D013779:Tetrodotoxin / Q000494:pharmacology; D014649:Vas Deferens / Q000187:drug effects
D000804:Angiotensin II; D013373:Substance P; D013779:Tetrodotoxin; D008012:Lidocaine; D010869:Pindolol; D001920:Bradykinin