In Vitro | In vitro activity: Medetomidine is a selectiveα2-adrenoceptor agonist, with Ki of 1.08 nM, exhibits 1620-fold selectivity over α1-adrenoceptor, has very weak or no binding to other neurotransmitter receptors. |
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In Vivo | In anesthetized rats, medetomidine (1-100 μg/kg, i.v.) induces a dose-dependent, relatively short-lived reduction in blood pressure and heart rate. In the pithed rat, medetomidine shows very potent vasopressor (PD50 1.7 μg/kg) and sympatho-inhibitory (ID50 1.6 μg/kg) effects without affecting basal heart rate. Medetomidine induces dose-dependent sedation, which at high doses (>100μg/kg) includes loss of the righting reflex and hypothermia. Medetomidine induces a decreases in the turnover rate of biogenic amines in the brain, dose-dependently inhibits norepinephrine (NE) turnover, inhibits brain dopamine turnover at high doses, decreases serotonin turnover. |
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