STUDIES ON THE HYPOTENSIVE ACTION OF DIHYDRO-ERGOKRYPTINE (DHK) AND EPINEPHRINE-REVERSAL IN THE DOG AND CAT

DHK produces a definite fall of blood pressure under morphine-urethane anesthesia but a transient elevation under thiopental-barbital anesthesia in the dog. In the latter case it is presumed that the reaction may be due to the potentiation of its peripheral pressor action by barbiturate. The following conclusions are reached by the results of four groups of experiments i.e. at normotensive or hypotensive state in the intact and spinal cat. The hypotensive action of DHK is produced by means of alive brain and its intact efferent pathways which may contain ganglion and cholinergic fibers. On the other hand, the epinephrine-reversal induced by DHK can be demonstrated regardless of the brain centers and of its efferent pathways as long as arterial blood pressure is maintained at a sufficiently high level.