Regulation of mouse placental lactogen secretion by factors secreted from the pituitary in vitro.
The effect of factors secreted from the pituitary on mouse placental lactogen I (mPL-I) and mPL-II secretion in vitro was examined. Co-culture of mouse placental cells from day 7 of pregnancy with the pituitary cells of the mother significantly stimulated mPL-I secretion but did not regulate mPL-II secretion. The effect on mPL-I secretion was dependent on the number of pituitary cells. The conditioned medium of pituitary cells also significantly stimulated mPL-I secretion but did not regulate mPL-II secretion. The stimulatory effect of mPL-I secretion was dependent on the volume of the conditioned medium. The number of cells containing mPL-I assessed by immunocytochemistry was increased by the co-culture in a cell number-dependent manner. Northern blot analysis for mPL-I indicated that treatment of placental cells with the pituitary-conditioned medium results in an increase of mPL-I gene expression. These findings suggest that factors secreted from the pituitary directly regulate mPL-I secretion, but not mPL-II secretion, before midpregnancy in vivo.
Yamaguchi
M
M
Department of Obstetrics and Gynecology, Osaka University Medical School, Japan.
Miyake
A
A
D000818:Animals; D002452:Cell Count; D002478:Cells, Cultured; D018920:Coculture Techniques; D017077:Culture Media, Conditioned; D005260:Female; D015870:Gene Expression; D051379:Mice; D008813:Mice, Inbred ICR; D010902:Pituitary Gland / Q000166:cytology / Q000378:metabolism*; D010920:Placenta / Q000166:cytology / Q000378:metabolism; D010928:Placental Lactogen / Q000235:genetics / Q000378:metabolism*; D011247:Pregnancy
D017077:Culture Media, Conditioned; C062303:placental lactogen II; C085699:placental lactogen I, rat; D010928:Placental Lactogen