The regulation of the prolactin receptor gene expression in the mammary gland of early pregnant mouse.
The purpose of this research was to examine the hormonal regulation of the PRL receptor (PRL-R) gene expression in the mammary gland of early pregnant mouse. Following reverse-transcription, the quantity of PRL-R mRNA was determined by the competitive polymerase chain reaction. The level of long form PRL-R (PRL-RL) mRNA changed cyclically with the highest at estrus and the lowest at diestrus II. PRL-RL mRNA was maintained at high levels for the first 3 days of pregnancy but declined to lower levels on day 5. Mice ovariectomized on day 2 of pregnancy maintained the same level of PRL-RL mRNA during the 24 h-period. The level of PRL-R mRNA increased more than 2- and 2.7-fold with 17 beta-estradiol and PRL, respectively, and the progesterone concentration decreased its levels to 71% of the vehicle-injected control. The increasing action with 17 beta-estradiol and PRL was suppressed by administration of progesterone. Mice ovariectomized on day 3 had a 1.8-fold higher level than that of the sham-operated control. The short form of PRL-R remained at low levels throughout the experiments. The results suggested that the expression of the PRL-R gene was suppressed when serum progesterone increased during early pregnancy.
Mizoguchi
Y
Y
Department of Animal Breeding, Faculty of Agriculture, University of Tokyo, Japan.
Kim
J Y
JY
Enami
J
J
Sakai
S
S
D000818:Animals; D018076:DNA, Complementary / Q000032:analysis / Q000235:genetics; D004958:Estradiol / Q000494:pharmacology; D004971:Estrus / Q000187:drug effects / Q000235:genetics*; D005260:Female; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects / Q000235:genetics*; D008321:Mammary Glands, Animal / Q000187:drug effects / Q000378:metabolism*; D051379:Mice; D008813:Mice, Inbred ICR; D010052:Ovariectomy; D016133:Polymerase Chain Reaction; D011247:Pregnancy; D011270:Pregnancy, Animal / Q000187:drug effects / Q000235:genetics* / Q000502:physiology; D011374:Progesterone / Q000494:pharmacology; D011388:Prolactin / Q000494:pharmacology; D012333:RNA, Messenger / Q000032:analysis / Q000187:drug effects / Q000235:genetics; D011981:Receptors, Prolactin / Q000187:drug effects / Q000235:genetics*
D018076:DNA, Complementary; D012333:RNA, Messenger; D011981:Receptors, Prolactin; D011374:Progesterone; D004958:Estradiol; D011388:Prolactin