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Brain NaK‐ATPases in Mice Differentially Sensitive to Alcohols
Author(s) -
Marks Michael J.,
Smolen Andrew,
Collins Allan C.
Publication year - 1984
Publication title -
alcoholism: clinical and experimental research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.267
H-Index - 153
eISSN - 1530-0277
pISSN - 0145-6008
DOI - 10.1111/j.1530-0277.1984.tb05685.x
Subject(s) - ouabain , chemistry , ethanol , atpase , biochemistry , isozyme , enzyme , gel electrophoresis , polyacrylamide gel electrophoresis , microbiology and biotechnology , chromatography , biology , sodium , organic chemistry
The isozymes of NaK‐ATPase were studied in the particulate fraction of homogenates prepared from cortex of LS and SS mice, two lines of mice that have been selectively bred for differential response to ethanol. In addition to a ouabain‐insensitive Mg‐ATPase, ouabain dose‐response curves have suggested the presence, in brain, of two NaK‐ATPase activities with different sensitivities to ouabain. These are designated low K, (4 times 10 ‐7 M) and high K 1 (2 times 10 ‐4 M). Ethanol differentially inhibited the ATPases: The ouabain‐insensitive activity was less sensitive to ethanol inhibition than were the two ouabain‐inhibitable activities. The low K 1 (brain specific) NaK‐ATPase was more sensitive than was the high K, activity. However, ethanol inhibited all three components of the ATPase activity in an identical fashion in the two mouse lines. The low K, activity was also more labile to thermal and p‐hydroxymercurobenzoate denaturabon than was the high K 1 activity. These measures did not differ between the LS and SS lines. SDS‐polyacrylamide electrophoresis of particulate fraction of cortical homogenates obtained from LS and SS mice revealed the presence of two protein bands with similar 32 P labeling in both lines. Given that etectrophoretic pattern and heat or p‐hydroxymercurobenzoate inhibition were identical, it seems unlikely that differences in ATPase activity, or inhibition by ethanol, are responsible for the different response of LS and SS mice to ethanol.