The blocking effects of tolazoline and propranolol on axial movements of incisor teeth and on changes in arterial blood pressure induced by adrenaline in rats.

Abstract

Axial tooth movements and arterial blood pressure were measured following intravenous injection of adrenaline, 1hr before, and 1 and 2hr after the injection of tolazoline (an α-adrenergic blocking agent) or propranolol (a β-adrenergic blocking agent). The initial increase in blood pressure induced by adrenaline was significantly suppressed and the successive decrease in blood pressure was markedly enhanced by pretreatment with tolazoline. In contrast to blood pressure changes, the initial extrusive tooth movement induced by adrenaline was not suppressed, and successive intrusive tooth movements induced by adrenaline were not potentiated, but suppressed. The initial increase in blood pressure induced by adrenaline was enhanced and the successive decrease in blood pressure was suppressed by pretreatment with propranolol. On the other hand, the initial extrusive tooth movement induced by adrenaline was not significantly potentiated, but successive intnsive tooth movements induced by adrenaline were markedly suppressed. Pressure within the socket that may induce axial tooth movements might be regulated by various factors, such as resistance of the blood vessels, blood flow in the socket, and systemic arterial blood pressure, all of which are liable to change following an injection of adrenaline under the influence of α-or β-adrenergic blockers.