Effects of anipamil on cardiovascular status and regional blood flow in anaesthetized rats

1. Anipamil, a long-acting analogue of verapamil, was tested at 1, 2.5 and 5 mg kg-1 i.v. for its effects on cardiovascular status and blood flow in different organs and vascular beds in rats anaesthetized with pentobarbitone. 2. Blood flow was determined by microsphere (57Co or 113Sn) injection before, and 1 h after, administration of anipamil at the above doses. 3. Anipamil produced a dose-dependent fall in blood pressure and heart rate. This was associated with a fall in peripheral resistance. At the highest dose there was, in addition, evidence of myocardial depression. 4. Both blood flow and conductance (flow corrected for blood pressure) were notably increased by anipamil in heart, liver and skeletal muscle beds, but were decreased, especially at the high doses, in kidneys, intestine and spleen. 5. The profile of the actions of anipamil on haemodynamic performance and flow was consistent with its proposed calcium antagonist actions. This profile was similar to that of verapamil.