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Indomethacin decreases both prolactin binding and membrane fluidity of ventral and dorso‐lateral lobes of rat prostate gland
Author(s) -
Dave Jitendra R.,
Witorsch Raphael J.
Publication year - 1983
Publication title -
the prostate
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.295
H-Index - 123
eISSN - 1097-0045
pISSN - 0270-4137
DOI - 10.1002/pros.2990040203
Subject(s) - prolactin , endocrinology , medicine , prostate , membrane fluidity , membrane , chemistry , biology , biochemistry , hormone , cancer
The objective of these studies was to examine the effects of in vivo treatment with indomethacin, a prostaglandin synthesis inhibitor, on prolactin binding activity and fluidity in membrane preparations of rat prostate gland. Adult male rats were treated with vehicle or either of two doses of indomethacin (3.8 μg/g body weight or 7.5 μg/g body weight) every 8 hr for 1, 2, and 3 days. Indomethacin treatment decreased prolactin binding in rat ventral and dorso‐lateral lobes of prostate gland in a time and dose‐dependent fashion. In ventral prostate membranes the higher dose of indomethacin decreased prolactin binding by approximately 80% after 3 days of treatment. Prolactin binding to membrane preparations from dorso‐lateral prostate gland of control animals was 10% of that observed for ventral prostate and decreased to undetectable levels within 24–48 hr after the start of indomethacin treatment. Scatchard analysis of the prolactin binding of ventral prostate indicated that indomethacin treatment decreased the number of prolactin binding sites rather than the apparent affinity constant. Prostatic membrane fluidity was measured by a fluorescence polarization technique. Dorso‐lateral prostate membrane preparations were found to have a higher membrane fluidity than those observed for ventral prostate membranes. The effects of indomethacin on membrane fluidity paralleled that of prolactin binding. Both ventral and dorso‐lateral prostatic membrane fluidity decreased after indomethacin treatment in a time and dose‐dependent manner. These simultaneous effects of indomethacin on prostatic prolactin binding and fluidity suggest that these phenomena are interrelated and that prostaglandins are involved in the maintenance of prolactin receptors in vivo .