Chronotropic and inotropic effects of atrial peptides on the isolated systemic heart of Octopus vulgaris.
The chronotropic and inotropic effects of four atrial peptides (cardiodilatin 1-16, atrial natriuretic factor 8-33 and atriopeptin I and III) on the isolated systemic heart of Octopus vulgaris were studied. Using a preparation that produces a physiological stroke volume at physiological input pressures, it was found that ANF, atriopeptin I and atriopeptin III exerted both negative chronotropic and inotropic effects. In contrast, cardiodilatin produced a positive inotropic effect. A dose-response curve of ANF is reported, showing a threshold concentration of about 10(-12) M. The pharmacological and physiological implications of these results are discussed in relation to some characteristics of the cephalopod systemic heart.
Agnisolo
C
C
Dipartimento di Fisiologia Generale ed Ambientale, Università di Napoli, Italy.
Cariello
L
L
De Santis
A
A
Miralto
A
A
Tota
B
B
D000818:Animals; D009320:Atrial Natriuretic Factor / Q000494:pharmacology*; D005260:Female; D006321:Heart / Q000187:drug effects*; D006339:Heart Rate / Q000187:drug effects; D008297:Male; D009200:Myocardial Contraction / Q000187:drug effects; D049831:Octopodiformes / Q000187:drug effects / Q000502:physiology*
D009320:Atrial Natriuretic Factor