Effects of anticonvulsants on cholinergic and GABAergic properties in the neuronal cell clone NG108-15 |
| |
Authors: | Charles D Searles Paul A Slesinger Harvey S Singer MD |
| |
Institution: | (1) Department of Neurology, Johns Hopkins University School of Medicine, Meyer 5-109, 600 N. Wolfe Street, 21205 Baltimore, Maryland;(2) Department of Pediatrics, Johns Hopkins University School of Medicine, Meyer 5-109, 600 N. Wolfe Street, 21205 Baltimore, Maryland |
| |
Abstract: | The effects of anticonvulsant drugs on growth, cholinergic, and GABAergic properties were examined in the neuronal cell clone NG108-15. Cells were exposed for 4 days to valproic acid, phenobarbital, phenytoin, or carbamazepine in concentrations equivalent to therapeutic free levels in human serum. Experiments were also performed with varying concentrations of a recently proposed antiepileptic, gamma-vinyl GABA. Of these five anticonvulsants, cell growth (total protein and cell counts) was decreased with valproic acid and phenytoin but only valproic acid and gamma-vinyl GABA altered neurotransmitter markers. Therapeutic concentrations of valproic acid increased choline acetyltransferase activity to 142% of control but had no effect on either the activity of glutamate decarboxylase or the level of GABA. The effects of a higher (toxic) concentration of valproic acid (200 g/ml) were similar to those induced by the differentiating agent dibutyryl cyclic AMP: both decreased cell growth, enhanced the activity of choline acetyltransferase and reduced the activity of glutamate decarboxylase. Gamma-vinyl GABA had no effect on cholinergic markers but, at 1300 g/ml, increased GABA levels to 135% of control despite the reduction of glutamate decarboxylase to 68% of control. In the NG108-15 cell clone, anticonvulsants have varying effects on cell growth, differentiation, and neurotransmitter systems. Our findings do not support the proposal that the mechanism of action for valproic acid, phenobarbital, phenytoin, and carbamazepine is via alteration of GABA levels. |
| |
Keywords: | Anticonvulsants acetylcholine GABA neuronal cell clone neurotoxicity differentiation |
本文献已被 SpringerLink 等数据库收录! |
|