Inhibition by ketamine and amphetamine analogs of the neurogenic nitrergic vasodilations in porcine basilar arteries.

Inhibition by ketamine and amphetamine analogs of the neurogenic nitrergic vasodilations in porcine basilar arteries. Toxicol Appl Pharmacol. 2016 May 31; Authors: Chen MF, Lai SY, Kung PC, Lin YC, Yang HI, Chen PY, Liu IY, Lua AC, Lee TJ Abstract The abuse of ketamine and amphetamine analogs is associated with incidence of hypertension and strokes involving activation of sympathetic activities. Large cerebral arteries at the base of the brain from several species receive dense sympathetic innervation which upon activation causes parasympathetic-nitrergic vasodilation with increased regional blood flow via axo-axonal interaction mechanism, serving as a protective mechanism to meet O2 demand in an acutely stressful situation. The present study was designed to examine effects of ketamine and amphetamine analogs on axo-axonal interaction-mediated neurogenic nitrergic vasodilation in porcine basilar arteries using techniques of blood-vessel myography, patch clamp and two-electrode voltage clamp, and calcium imaging. In U-46,619-contracted basilar arterial rings, nicotine (100μM) and electrical depolarization of nitrergic nerves by transmural nerve stimulation (TNS, 8Hz) elicited neurogenic nitrergic vasodilations. Ketamine and amphetamine analogs concentration-dependently inhibited nicotine-induced parasympathetic-nitrergic vasodilation without affecting that induced by TNS, nitroprusside or isoproterenol. Ketamine and amphetamine analo...
Source: Toxicology and Applied Pharmacology - Category: Toxicology Authors: Tags: Toxicol Appl Pharmacol Source Type: research