Expression of insulin-like growth factor I mRNA in rat luteal tissue increases with functional regression of the corpus luteum.
The expression of insulin-like growth factor (IGF-I) messenger ribonucleic acid (mRNA) in rat corpora lutea (CL) was determined during the second half of pregnancy and early lactation, and the effect of prostaglandin F2 alpha on expression was examined during late pregnancy. Northern blot analysis revealed 4 species of transcripts in CL. Radioactivity of dot blots was measured directly for quantitative analysis of expression. The expression in CL increased during the second half of pregnancy, peaked around parturition, and declined thereafter. The injection of 1 mg of prostaglandin F2 alpha at 1300 and 1800 h on day 18 of pregnancy, which decreased plasma progesterone concentration, doubled luteal expression of IGF-I mRNA 1 day later. These results suggest that functional regression of the corpus luteum is correlated with the increased expression of IGF-I mRNA in luteal tissue in rats.
Tamada
H
H
Department of Animal Reproduction, College of Agriculture, University of Osaka Prefecture, Japan.
Kitashin
H
H
Sawada
T
T
Mori
J
J
D000818:Animals; D015152:Blotting, Northern; D001921:Brain / Q000378:metabolism; D003338:Corpus Luteum / Q000378:metabolism*; D015237:Dinoprost / Q000494:pharmacology; D005260:Female; D015870:Gene Expression; D005865:Gestational Age; D007334:Insulin-Like Growth Factor I / Q000096:biosynthesis / Q000235:genetics*; D007774:Lactation / Q000378:metabolism; D008099:Liver / Q000378:metabolism; D003341:Luteolysis / Q000378:metabolism*; D009929:Organ Size; D011247:Pregnancy; D011374:Progesterone / Q000097:blood; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley
D012333:RNA, Messenger; D011374:Progesterone; D007334:Insulin-Like Growth Factor I; D015237:Dinoprost