The effect of some drugs with purported antianoxic effect on veratridine-induced purine release from isolated rat hypothalamic synaptosomes.

Several drugs claimed to protect against anoxic damage to the brain and/or to aleviate symptoms of senility were tested for their ability to influence purine overflow from hypothalamic synaptosomes. Theophylline did not influence the total purine release but tended to decrease the nucleoside and increase the nucleotide release. Cyclic nucleotide phosphodiesterase inhibitors were ineffective, whereas drugs that inhibit carrier mediated nucleoside transport inhibited veratridine-induced purine release. Some ergot derivatives, some vinca-analogues and the vasodilator ifenprodil also decreased stimulated purine release, but their effect could not be attributed to adenosine transport inhibition. The results suggest that drugs are reported to aleviate symptoms of anoxic damage or senility may inhibit the release of adenosine and related compounds in the central nervous system. Some possible reasons why a decreased purine release may protect against ischaemic brain damage are discussed.