INFLUENCE OF CONTINUOUS PERFUSION WITH ADRENALINE ON THE WORKING RAT-HEART

In this study, the effect of perfusion with increasing adrenaline conc entrations on the performance of the working rat heart was continuousl y monitored. The results showed that adrenaline increased the rate of heart beat ar a faster pace than the mechanical parameters. When the m aximum heart-beat rate was reached, this value was maintained, whereas the mechanical function started to decline soon after a plateau in pe rformance was attained. Increasing the adrenaline concentration caused the inotropic function to respond up to a plateau value and then to d ecline. Adenosine production increased at the time of decline in mecha nical performance. This increase in adenosine levels might be one of t he factors causing the suppression of contractility, possibly by inhib ition of kinase activity.