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Potentiation of the depression by adenosine of rat cerebral cortical neurones by progestational agents
Author(s) -
Phillis John W.
Publication year - 1986
Publication title -
british journal of pharmacology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.432
H-Index - 211
eISSN - 1476-5381
pISSN - 0007-1188
DOI - 10.1111/j.1476-5381.1986.tb11173.x
Subject(s) - adenosine , long term potentiation , neuroscience , depression (economics) , cortical spreading depression , cerebral cortex , endocrinology , medicine , biology , pharmacology , chemistry , receptor , macroeconomics , migraine , economics
1 The effects of four progestational agents pregnenolone sulphate, cyproterone acetate, norethindrone acetate and progesterone, on adenosine‐evoked depression of the firing of rat cerebral cortical neurones have been studied. 2 When applied iontophoretically, pregnenolone sulphate, cyproterone, and norethindrone enhanced the actions of iontophoretically applied adenosine and failed to potentiate the depressant effects of adenosine 5′‐N‐ethylcarboxamide and γ‐aminobutyric acid. 3 Cyproterone acetate (50 μg kg −1 ) and progesterone (200 μg kg −1 ) administered intravenously enhanced the depressant actions of iontophoretically applied adenosine. 4 When applied by large currents, cyproterone, and less frequently norethindrone, depressed the firing of cerebral cortical neurones. The depressant effects of cyproterone were antagonized by caffeine. 5 Pregnenolone sulphate tended to excite cortical neurones but neither this action, nor its potentiation of adenosine were reproduced by application of sulphate ions. 6 It is hypothesized that some of the psychotropic actions of progestational agents may involve an enhancement of ‘purinergic’ tone in the central nervous system.