Prolactin stimulation of iodide uptake into mouse mammary gland
explants.
Rillema, J. A., and T. X. Yu.
Department of Physiology, Wayne State University School of
Medicine, Detroit, MI 48201 U.S.A.
APStracts 3:0143E, 1996.
These studies show that PRL stimulates iodide accumulation in cultured
mouse mammary tissues. This effect of PRL likely causes the elevated
concentration of iodide which occurs in the milk of a number of
species. In time-course studies an initial effect of PRL occurred
after 4 hours, while a maximum 2-3 fold increase was observed after
24 hr. In dose-response studies, 1 ng/ml PRL elicited a significant
response, while PRL concentrations above 5 ng/ml stimulated maximum
responses. Other lactogenic hormones including hGH and hPL also
stimulated iodide uptake, whereas nonlactogenic substances including
bGH, BSA and TSH were without effect. PRL had no effect on iodide
uptake into fat cells. In further studies it was shown that PRL
stimulates iodide incorporation into macromolecules in a 10% TCA
precipitable tissue fraction as well as in a pH 4.6 isoelectric
precipitate. The findings from these studies suggest that PRL may
stimulate both the accumulation of free iodide in milk, as well as
iodide incorporation into milk proteins.
Received 24 April 1996; accepted in final form 12 July 1996.
APS Manuscript Number E203-6.
Article publication pending Am. J. Physiol. (Endocrinol. Metab.).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 25 July 1996