Evidence for both H and H2-histamine receptors in rabbit atria.
Indian J Physiol Pharmacol
;
1980 Jan-Mar; 24(1): 37-42
Artículo
en Inglés
| IMSEAR
| ID: sea-107724
ABSTRACT
Spontaneously beating isolated atria of rabbits responded to histamine (0.5-16 micrograms/ml) with positive chrono- and inotropism. However, the inotropic response was greater than chronotropic one. The concentration-response curve of histamine for chronotropic effect was markedly shifted to the right in the presence of 0.5 micrograms/ml metiamide (H2-receptor antagonist), which per se augmented the control contractile amplitude in all the experiments. The rightward shift of chronotropic concentration response curve with mepyramine (H1-antagonist) was, however, moderate. On the contrary, the inotropic concentration response curve of histamine was shifted to much greater extent to right with mepyramine (0.62 micrograms/ml) than with metiamide, thus suggesting a greater share of H1 than H2-receptors in the mediation of positive inotropic effect of histamine. The chronotropic effect appears to be mediated predominently by H2-receptors. Unlike metiamide, mepyramine did not alter the spontaneous frequency or amplitude of contraction. The present study, thus lends support for dual histamine receptors in rabbit atria.
Texto completo:
Disponible
Índice:
IMSEAR (Asia Sudoriental)
Asunto principal:
Pirilamina
/
Conejos
/
Estimulación Química
/
Femenino
/
Masculino
/
Receptores Histamínicos
/
Receptores Histamínicos H1
/
Receptores Histamínicos H2
/
Histamina
/
Interacciones Farmacológicas
Idioma:
Inglés
Revista:
Indian J Physiol Pharmacol
Año:
1980
Tipo del documento:
Artículo
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