Anaesthetic doses of pentobarbital antagonize phosphatidylinositol hydrolysis induced by substance P or carbachol in the spinal cord and cerebral cortex of the rat

Abstract

Basal as well as agonist (100 μM substance P or 2 mM carbachol)-stimulated phosphatidylinositol hydrolysis was investigated in slices of rat spinal cord and cerebral cortex, in the presence and absence of pentobarbital (5–50 μM in vitro or 65 mg/kg in vivo) or urethane (0.2 mM in vitro or 1.4 g/kg in vivo). Urethane was without effect; pentobarbital, however, inhibited the basal hydrolysis and the agonist-stimulated phosphatidylinositol hydrolysis (in dose-dependent fashion in vitro). It is suggested that inhibition of phosphatidylinositol hydrolysis may be part of the cellular mechanisms by which pentobarbital produces anaesthesia.