[Cardiovascular effects of two synthetic enkephalin analogues following intracoronary administration in dogs (author's transl)].

Haemodynamic changes following intracoronary injection of two synthetic Met5-enkephalin analogues (FK 33-824 and DALA) with prolonged action as compared with "natural" enkephalines were investigated in anaesthetized dogs (n = 5; dosage; 200, 400, 600 micrograms of both substances i. cor.). DALA led to a shortlasting (5 minutes) rise in heart rate associated with an increase in cardiac output and left ventricular dp/dt max. Besides, a fall in mean arterial blood pressure was noted. No alterations in the pulmonary circulation were encountered. FK 33-824 elicited similar, but unpronounced changes. Direct influences on baroreceptor activity or endogenous release of vasoactive substances as the cause of circulatory effects occuring primarily under DALA were discussed. It is concluded that the cardiovascular effects of synthetic opioids resemble those of morphine and its related compounds.