Sex-dependent inhibition by retinoic acid of thyroid-hormone action on rabbit reticulocyte Ca2(+)-ATPase activity.
The interaction was examined in vitro of retinoic acid and thyroid hormone with rabbit reticulocyte Ca2(+)-ATPase. L-Thyroxine (T4) (0.1 nM) stimulated female-source Ca2(+)-ATPase activity (+21%; P less than 0.03) and inhibited male-source enzyme (-20%; P less than 0.05). Addition of retinoic acid (10 nM-1 microM) did not influence T4-inhibitable male-source Ca2(+)-ATPase, but caused a 52% loss of T4 effect on the female-source enzyme. Incubation of female-source membranes with testosterone caused the enzyme response to T4 and retinoic acid to become that of male-source membranes, and the male-source enzyme response was converted into the 'female' pattern by exposure to 17 beta-oestradiol. We postulate that a membrane-associated sex-steroid-dependent factor imparts a gender-specific interaction of thyroid hormone and retinoic acid on Ca2(+)-ATPase, and that ultimately the factor is shed during erythrocyte maturation.
Davis
F B
FB
Department of Medicine, State University of New York, Buffalo School of Medicine and Biomedical Sciences, NY.
Smith
T J
TJ
Davis
P J
PJ
Lawrence
W D
WD
Ryan
A J
AJ
Farrell
M O
MO
Blas
S D
SD
D000818:Animals; D000252:Calcium-Transporting ATPases / Q000378:metabolism*; D004958:Estradiol / Q000494:pharmacology; D005260:Female; D012739:Gonadal Steroid Hormones / Q000494:pharmacology*; D008297:Male; D011817:Rabbits; D012156:Reticulocytes / Q000187:drug effects / Q000201:enzymology*; D013739:Testosterone / Q000494:pharmacology; D013974:Thyroxine / Q000494:pharmacology*; D014212:Tretinoin / Q000494:pharmacology*; D014285:Triiodothyronine, Reverse / Q000494:pharmacology*
D012739:Gonadal Steroid Hormones; D013739:Testosterone; D004958:Estradiol; D014212:Tretinoin; D014285:Triiodothyronine, Reverse; D000252:Calcium-Transporting ATPases; D013974:Thyroxine