THE EFFECT OF TRANQUILIZERS ON THE CONTRACTILE RESPONSE OF CEREBRAL ARTERIES

¹ Departments of Pathology, Bellevue Hospital and New York University School of Medicine, New York, N. Y.

Phenothianines and reserpine prevent or reduce the pial artery constriction which otherwise folows local administration of BaCl₂. Moreover, local application of procaine, atropine, guanethidine, histamine, methacholine, acetylcholine, and methysergide, all failed to prevent the reaction to BaCl₂. On the other hand, the systemic administration of reserpine and phenothiazine did not influence the constrictor response to local BaCl₂, although tranquilization was achieved. In addition, at least one vasoactive agent without the ability to influence behavior, nylidrin HCl, was tested in a previous study and found to inhibit the response to BaCl₂. Thus, hypotheses relating tranquilization to altered cerebrovascular reactivity remain unproven. However, the striking influence of locally applied tranquilizers on the response of pial arteries is an important and heretofore unreported finding. It is suggested that these effects are representative of reserpine and phenothiazine action on smooth muscle in general. Further study of this interaction should shed light on the mechanism by which these tranquilizers affect a variety of electrically excitable structures, including the neuron.

This article has been cited by other articles:

				W. I. Rosenblum Cerebral Microcirculation: a Review Emphasizing the Interrelationship of Local Blood Flow and Neuronal Function Angiology, August 1, 1965; 16(8): 485 - 507. [PDF]