Clarence E. Powell

HYPOTENSIVE ACTIVITY OF 3-(N-METHYL-T-BUTYL-AMINO)-1-BROMO-3-METHYL-1-BUTYNE HYDROCHLORIDE.

Summary It has been shown that haloethynyl derivatives have a hypotensive action in animals with a minimum of ganglionic blockade. Oral administration of compound 37157 resulted in a significant fall in blood pressure in renal hypertensive rats and dogs. In the anesthetized cat, compound 37157 lowered blood pressure and only partially blocked the contraction of the electrically stimulated nictitating membrane. The anesthetized norm-otensive dog responded with a fall in blood pressure, persisting for 5 hours. Respiration and electrocardiogram were not altered. The pressor response to carotid occlusion was completely abolished. Hypotensive activity could not be elicited in decerebrate cats and dogs, indicating partial central activity. In this preparation the pressor response to levarterenol was augmented. Compound 37157 stimulated the rabbit aortic strip and produced a delayed block of the response to angiotensin amide and levarterenol. The spastic action of angiotensin amide and serotonin on isolated ileum preparations was inhibited by 37157. The isolated rabbit uterus was stimulated. In the perfused isolated rabbit heart, there was a decrease in cardiac contractility, heart rate, and coronary flow.