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Ethanol's Effects on Cortical Adenylate Cyclase Activity
Author(s) -
Saito Toshikazu,
Lee John M.,
Tabakoff Boris
Publication year - 1985
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1111/j.1471-4159.1985.tb08722.x
Subject(s) - chemistry , ethanol , stimulation , cyclase , medicine , endocrinology , adenylate kinase , receptor , cerebral cortex , digitonin , biophysics , membrane , biochemistry , biology
The effects of ethanol on β‐adrenergic receptor‐coupled adenylate cyclase (AC) of mouse cerebral cortex were examined. The addition of ethanol (20–500 m M ) to incubation mixtures containing cortical membranes demonstrated that ethanol could increase AC activity and potentiate the stimulatory effects of guanylylimidodiphosphate [Gpp(NH)p] on AC activity. Ethanol increased the rate of activation of AC by guanine nucleotides and concomitantly decreased the EC 50 for magnesium required to achieve maximal stimulation of cortical AC. The EC 50 values for Gpp(NH)p and isoproterenol stimulation of AC activity were also altered by ethanol. Ethanol was capable of stimulating AC extracted by use of digitonin. The AC activity in the digitonin extract was no longer sensitive to the addition of Gpp(NH)p or NaF, but was still stimulated by ethanol. We propose multiple sites of action for ethanol in stimulating cortical AC activity. These sites include actions at the β‐adrenergic receptor, at the G/F coupling proteins, and at the catalytic unit of cortical AC. Comparison of ethanol's actions on cortical β receptor coupled AC activity with prior reported actions of ethanol on striatal dopamine (DA)‐sensitive AC indicated differential sensitivities of these two AC systems to ethanol. These differences may be determined by specific coupling characteristics of the striatal and cortical AC systems or by differences in the plasma membranes in which striatal and cortical AC systems are located.