BACKGROUND: PC12 cells, derived from @entity35 @entity1911 , express neuronal nicotinic @entity934 receptors (nAchRs) and P2X purinergic receptors, both of which resemble the receptors in postganglionic sympathetic neurons. The former is the established and the latter is the putative receptor to mediate fast synaptic transmission. The authors investigated effects of thiopental on these two ligand-gated ion channels. METHODS: Whole cell currents were recorded in PC12 cells without treatment of nerve growth factor, using conventional whole cell patch clamp technique. @entity1239 or @entity855 ( @entity855 ) 30 microM was applied for 4-5 s in the absence or presence of thiopental 3-300 microM. RESULTS: @entity1239 induced the rapidly decaying inward current at -60 mV, which exhibited the characteristics of the neuronal nAchR-mediated current. Thiopental inhibited the @entity1239 -induced inward current and accelerated the current decay in a dose-dependent manner, resulting in the greater effects on the steady current than the peak current. IC50s for the peak and steady current were 56.7 and 7.4 microM, when the anesthetic was coapplied with @entity1239 . Thiopental's inhibition was not associated with a change in the reversal potential and was voltage-independent at membrane potential of -30 to -70 mV. Most of thiopental's effects seemed to require channel opening. In contrast to the @entity1239 -induced current, thiopental had little effect on the current elicited by @entity855 . CONCLUSIONS: Thiopental, whose reported EC50 for general anesthesia is 25 microM, inhibited the neuronal nAchR-mediated current but not the P2X receptor-mediated response in PC12 cells at clinically relevant concentrations. Inhibition may result in suppression of synaptic transmission in sympathetic ganglia.

Differential effects of thiopental on neuronal nicotinic XXXX receptors and P2X purinergic receptors in PC12 cells.

@entity1911 :: ('MESH:D010673', 'Disease') :: ['pheochromocytoma'] @entity1239 :: ('MESH:D009538', 'Chemical') :: ['Nicotine', 'nicotine'] @entity35 :: ('10116', 'Species') :: ['rat'] @entity855 :: ('MESH:D000255', 'Chemical') :: ['adenosine triphosphate', 'ATP'] @entity934 :: ('MESH:D000109', 'Chemical') :: ['acetylcholine']
@entity934 :: (MESH:D000109,Chemical) :: ['acetylcholine']
