THE RELATIVE POTENCY OF PENTOBARBITAL IN SUPPRESSING THE KAINIC ACID-INDUCED OR THE N-METHYL-D-ASPARTIC ACID-INDUCED ENHANCEMENT OF CGMP IN CEREBELLAR CELLS

Primary cultures of rat cerebellar cells were pretreated with various dosages of pentobarbital before the addition of kainic acid or N-methyl-D-aspartic acid in order to assess effects of this drug on the enhancement of cyclic guanosine-3',5'-phosphate (cyclic GMP) mediated by these excitatory agonists. Pentobarbital significantly suppressed kainic acid-induced increases in this cyclic nucleotide at concentrations as low as 5-mu-M but was only effective in suppressing the N-methyl-D-aspartic acid enhancement at dosages of 100-mu-M or greater. These data suggest that this barbiturate is a more effective depressant of the stimulatory effects of kainic acid as compared to N-methyl-D-aspartic acid.