Preferential expression of long form prolactin receptor mRNA in the rat brain during the oestrous cycle, pregnancy and lactation: hormones involved in its gene expression.
The mRNA species for prolactin receptor (PRL-R) isoforms, long and short form PRL-Rs, were estimated by the reverse transcription-polymerase chain reaction method in the rat brain (cerebrum) during the oestrous cycle, pregnancy and lactation. The levels of long form PRL-R mRNA increased at pro-oestrus and oestrus, at the same time as serum prolactin levels increased, whereas the mRNA level of short form PRL-R was relatively unchanged. Long form PRL-R mRNA expression was also markedly increased in the brain at mid- and late gestation, and this elevated mRNA level was maintained during the period of lactation. In contrast, basal levels of short form PRL-R mRNA were also maintained throughout these periods of gestation and lactation. Ovariectomy moderately reduced brain mRNA levels of both long and short form PRL-R from the levels of those in control dioestrous rats, and hypophysectomy further suppressed them to the lowest levels. Administration of oestradiol valerate (E2V) or 17 alpha-hydroxyprogesterone caproate (17OHPC) to ovariectomized rats resulted in dramatic increases in long form PRL-R mRNA levels in the brain, whereas no significant increase in short form PRL-R mRNA was observed. In rats which were ovariectomized and hypophysectomized, the administration of 17OHPC, rat prolactin or rat GH partially restored the brain level of long form PRL-R mRNA but not short form PRL-R mRNA.(ABSTRACT TRUNCATED AT 250 WORDS)
Sugiyama
T
T
Department of Biochemistry, Mie University Faculty of Medicine, Japan.
Minoura
H
H
Kawabe
N
N
Tanaka
M
M
Nakashima
K
K
D000077713:17 alpha-Hydroxyprogesterone Caproate; D000818:Animals; D001483:Base Sequence; D015139:Blotting, Southern; D001921:Brain / Q000378:metabolism*; D017931:DNA Primers / Q000235:genetics; D004958:Estradiol / Q000494:pharmacology; D004971:Estrus / Q000502:physiology*; D005260:Female; D015870:Gene Expression / Q000502:physiology; D013006:Growth Hormone / Q000494:pharmacology; D006908:Hydroxyprogesterones / Q000494:pharmacology; D007016:Hypophysectomy; D007774:Lactation / Q000502:physiology*; D008969:Molecular Sequence Data; D015345:Oligonucleotide Probes / Q000235:genetics; D010052:Ovariectomy; D016133:Polymerase Chain Reaction; D011247:Pregnancy; D011270:Pregnancy, Animal / Q000502:physiology*; D045167:Progesterone Congeners / Q000494:pharmacology; D011388:Prolactin / Q000494:pharmacology; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D017207:Rats, Sprague-Dawley; D011981:Receptors, Prolactin / Q000737:chemistry / Q000235:genetics*
D017931:DNA Primers; D006908:Hydroxyprogesterones; D015345:Oligonucleotide Probes; D045167:Progesterone Congeners; D012333:RNA, Messenger; D011981:Receptors, Prolactin; D000077713:17 alpha-Hydroxyprogesterone Caproate; D004958:Estradiol; D011388:Prolactin; D013006:Growth Hormone