Effects of Vasoactive Drugs and Nerve Stimulation on Blood Flow in the Tooth Pulp and Allied Structures of the Cat

¹ Department of Physiology and Pharmacology, New York University College of Dentistry, New York, New York

The electrical impedance technique for investigating blood flow in the tooth pulp and associated dental structures has been described, and the results of experiments with over fifty cats have been reported. Experiments with the vasopressor drug epinephrine, administered both locally and systemically, clearly indicated that this drug is capable of altering mandibular and pulpal blood flow, with or without concomitant change in systemic pressure. Amyl nitrite, isoproterenol, and methacholine were the vasodepressor drugs employed in this study. Comparison of the results obtained with these drugs indicated that changes in local resistance and arterial pressure, the latter produced by changes in cardiac output and cardiac rate, influence the direction of blood-flow change in the pulp and related structures. Stimulation of the peripheral end of the cervical sympathetic nerve caused a reduction in blood flow in the tooth pulp and ear, with no significant charge in mandibular blood flow. Marked increase in intensity of stimulation resulted in some experiments in a small decrease in mandibular flow.