Reversal of vasopressin-induced coronary vasoconstriction by a PGE1 analogue (ONO 1206) in primates.

17 (S)methyl-omega-homo trans delta 2 PGE1 (ONO 1206) an analogue of PGE1 was studied on vasopressin-induced ECG changes in four male monkeys and three female baboons. Bolus intravenous doses of vasopressin (0.8 I.U. to 1.0 I.U./kg) produced flattening of the T wave (2 monkeys) elevation of ST segment (1 baboon and 1 monkey) and inversion of T wave (1 baboon). Inverted T waves were also present in one baboon and one monkey prior to any drug administration. In four out of seven animals, boLus intravenous doses (5 to 15 micrograms/kg) of ONO 1206 reversed the ECG changes produced by vasopressin and in one animal ONO 1206 reversed the existing inverted T wave. These findings indicate that vasopressin is a suitable agent for the induction of coronary vasoconstriction in primates and that ONO 1206 is able to reverse this effect.