RESUMEN

We studied the effects of angiotensin (Ang) I and II in a variety of isolated human cardiac tissues contracting under physiological conditions (37 degrees C, 60 beats.min-1). Ang I and II consistently increased the peak developed force of human atrial muscles by 30-40%, an effect that was completely blocked by 10(-6) M saralasine, but not by the combination of prazosin and propranolol. However, neither Ang I or II had significant inotropic effects in right and left ventricular human preparations. We were also able to demonstrate that the positive inotropic effect of Ang II in human right atrial tissue is mediated by the AT1 receptor subtype but not the AT2 receptor subtype.

Asunto(s)

Función Atrial , Hemodinámica/fisiología , Contracción Miocárdica/fisiología , Receptores de Angiotensina/fisiología , Función Ventricular , Angiotensina I/fisiología , Angiotensina II/fisiología , Técnicas de Cultivo , Relación Dosis-Respuesta a Droga , Atrios Cardíacos/efectos de los fármacos , Ventrículos Cardíacos/efectos de los fármacos , Hemodinámica/efectos de los fármacos , Humanos , Contracción Miocárdica/efectos de los fármacos , Prazosina/farmacología , Propranolol/farmacología , Receptores de Angiotensina/efectos de los fármacos , Saralasina/farmacología