Effects of activin on hormone secretion by single female rat pituitary cells: analysis by cell immunoblot assay.
We investigated the effect of activin A on secretion of LH, FSH, and prolactin (PRL) by female cultured rat pituitary cells at the single-cell level by means of the cell immunoblot assay. Anterior pituitary cells from 8-week-old female rats were preincubated with or without activin A for 24 h, after which they were monodispersed and immediately used for cell immunoblot assay. The percentages of LH-, FSH- and PRL-immunoreactive cell blots detected were 5.5, 5.3 and 43.1%, respectively, of all pituitary cells applied to the transfer membrane. The percentage of LH-secreting cells and mean LH secretion per cell did not change after treatment with activin. In contrast, activin significantly increased the percentage of FSH-secreting cells and mean FSH secretion per cell to 136.0 and 114. 5% respectively. In addition, activin significantly decreased the percentage of PRL-secreting cells and mean PRL secretion per cell to 52.2 and 72.0% respectively. These results suggest that (1) activin A has effects on female rat pituitary cells that increase not only the amount of FSH secretion per cell but also the number of FSH-secreting cells, and (2) activin A decreases both the amount of PRL secretion per cell and the number of PRL-secreting cells.
Miyamoto
S
S
Department of Obstetrics and Gynecology, School of Medicine, University of Tokushima, Tokushima 770-8503, Japan.
Irahara
M
M
Ushigoe
K
K
Kuwahara
A
A
Sugino
H
H
Aono
T
T
D028341:Activins; D000818:Animals; D002452:Cell Count; D002478:Cells, Cultured; D005260:Female; D005640:Follicle Stimulating Hormone / Q000378:metabolism; D006065:Gonadotropins, Pituitary / Q000378:metabolism*; D006133:Growth Substances / Q000494:pharmacology*; D015151:Immunoblotting; D007265:Inhibins / Q000494:pharmacology*; D007986:Luteinizing Hormone / Q000378:metabolism; D010902:Pituitary Gland / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D011388:Prolactin / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar
D006065:Gonadotropins, Pituitary; D006133:Growth Substances; D028341:Activins; D007265:Inhibins; D011388:Prolactin; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone