Effect of prolactin on sodium iodide symporter expression in mouse mammary gland explants.
Iodide accumulates in milk at a concentration that is more than an order of magnitude higher than the iodide concentration in maternal plasma. In earlier studies from our laboratory, we have shown that prolactin (PRL) enhances iodide accumulation by two- to threefold in cultured mammary tissues taken from pregnant mice. In the present studies, we demonstrate via Western blotting techniques that prolactin elevates the quantity of the sodium iodide symporter (NIS) in cultured mouse mammary tissues. In time-course studies, the onset of the PRL effect of NIS accumulation was found to be between 4 and 16 h after addition of PRL to the explants. The lowest PRL concentration that elicited a significant response was 1 ng/ml, and a maximum effect was elicited with PRL concentrations >100 ng/ml. Actinomycin D, cycloheximide, and thiocyanate abolished the PRL effect on NIS accumulation, whereas perchlorate was without effect. These studies suggest that the PRL stimulation of iodide accumulation in milk is mediated, at least in part, by the PRL stimulation of NIS accumulation in mammary gland tissues. These studies further demonstrate that the PRL effect on NIS accumulation occurs via an RNA protein synthesis-dependent mechanism.
Rillema
J A
JA
Department of Physiology, Wayne State University School of Medicine, Detroit, Michigan 48201, USA. jrillema@med.wayne.edu
Yu
T X
TX
Jhiang
S M
SM
D000818:Animals; D002352:Carrier Proteins / Q000096:biosynthesis* / Q000378:metabolism; D003513:Cycloheximide / Q000494:pharmacology; D003609:Dactinomycin / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D005260:Female; D066298:In Vitro Techniques; D017136:Ion Transport / Q000187:drug effects / Q000502:physiology*; D008321:Mammary Glands, Animal / Q000378:metabolism*; D008565:Membrane Proteins / Q000096:biosynthesis*; D051379:Mice; D019384:Nucleic Acid Synthesis Inhibitors / Q000494:pharmacology; D010472:Perchlorates / Q000494:pharmacology; D011247:Pregnancy; D011388:Prolactin / Q000378:metabolism* / Q000494:pharmacology; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology; D011994:Recombinant Proteins / Q000378:metabolism; D012974:Sodium Iodide / Q000378:metabolism*; D027981:Symporters; D013861:Thiocyanates / Q000494:pharmacology; D000099209:Sodium-Iodide Symporters
D002352:Carrier Proteins; D003513:Cycloheximide; D003609:Dactinomycin; D008565:Membrane Proteins; D019384:Nucleic Acid Synthesis Inhibitors; D010472:Perchlorates; D011388:Prolactin; D011500:Protein Synthesis Inhibitors; D011994:Recombinant Proteins; D012974:Sodium Iodide; D027981:Symporters; D013861:Thiocyanates; D000099209:Sodium-Iodide Symporters; C009941:potassium thiocyanate