摘要：

Methylxanthines, adenosine analogs, phosphodiesterase inhibitors and adenosine deaminase have been used to assess the role of adenosine in stimulation of radioactive cyclic AMP formation by ATP, cyclic AMP, glutamate, veratridine, ouabain, histamine and histamine-norepinephrine combination in [ 14C]adenine-labeled guinea pig cerebral cortical slices. Theophylline and isobutylmethylxanthine effectively antagonized the response to adenosine, ATP, cyclic AMP, an adenosine-histamine combination, glutamate and veratridine, had lesser effects on the response to ouabain and the histamine-norepinephrine combination and had no significant antagonistic effect on the histamine response. 2′-Deoxyadenosine had a similar profile of antagonistic effects with the exception of the glutamate response where it had no antagonistic action. Adenine xylofuranoside was an effective antagonist of responses to all agents, a result suggestive of a non-specific blockade of adenylate cyclases. Adenosine deaminase was an effective antagonist of the response to adenosine, ATP, cyclic AMP, an adenosine-histamine combination, veratridine and glutamate, but also partially antagonized the response to histamine and the histamine-norepinephrine combination. The phosphodiesterase inhibitors, papaverine, RO 20–1724 and diazepam, potentiated the response to amines. The latter two compounds also potentiated the response to adenosine and glutamate. The results suggest a role for adenosine in responses to most agents in brain slices and indicate that 2′-deoxyadenosine may be a more specific adenosine antagonist than either methylxanthines or adenosine deaminase.

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