Sensitivity of different segments of rabbit aorta to acetylcholine and isoproterenol.

In order to determine whether or not reserpine-induced supersensitivity was affected or reflected in differences in sensitivities to acetylcholine and isoproterenol in different segments of the rabbit aorta, segments of aorta, taken at two different distances from the arch, were tested for their sensitivities to these two agonists. Sensitivity and maximum responses to acetylcholine were lower in the more distal segment. Sensitivity to isoproterenol of the segments was not different while the maximum responses were lower in the more distal segment. Reserpine-induced supersensitivity to both agonists was similar in both aortic segments.