The effects of medetomidine, an α-2-adrenoceptor agonist, and cocaine on the tooth pulp-evoked jaw-opening reflex in cat

摘要: Abstract In the pentobarbitone-anesthetized cat, threshold of tooth pupl-elicited jaw-opening reflex was elevated in a dose-dependent way (30–100 μg/kg, IP) following administration medetomidine, an α-2-adrenoceptor agonist. This elevation significantly reduced by atipamezole (1 mg/kg, IP), antagonist. The inhibitory interaction between two successive dental stimuli applied to same (in-field inhibition) suppressed lower dose medetomidine (30 μg/kg) than single electrical pulses (55 μg/kg). Only highest used (100 influenced temporally facilitated facilitation) response. comparison, cocaine, nonspecific monoaminergic agent, did not produce significant pulp-elicited (1–25 IP). It is concluded that through action on α-2-adrenoceptors, can suppress predominantly nociceptive trigeminal anesthetized cats. evoked electric pulses, in-field inhibition, and facilitation display differential sensitivities effects.