Production and regulation of inhibin subunits in pituitary gonadotropes.
Two related proteins, inhibin and activin, are produced and secreted by the gonads and act at the pituitary to regulate FSH secretion. In the present study, the alpha and beta B, but not the beta A, polypeptide subunits of inhibin were localized in the cytoplasm of FSH- and LH-immunoreactive (ir) gonadotropes. Ovariectomy (OVX) increased the size and number of cells immunoreactive for inhibin-alpha and -beta B as well as the mRNAs encoding these subunits. Treatment with estrogen prevented these effects. These results suggest that pituitary gonadotropes are sources, as well as targets, of inhibin-related peptides, whose expression in the pituitary is modulated by ovarian factors.
Roberts
V
V
Laboratory of Neuronal Structure and Function, Salk Institute for Biological Studies, La Jolla, CA 92037.
Meunier
H
H
Vaughan
J
J
Rivier
J
J
Rivier
C
C
Vale
W
W
Sawchenko
P
P
D000818:Animals; D003593:Cytoplasm / Q000378:metabolism; D004720:Endonucleases; D005260:Female; D005455:Fluorescent Antibody Technique; D005640:Follicle Stimulating Hormone / Q000378:metabolism*; D007265:Inhibins / Q000096:biosynthesis* / Q000235:genetics; D007986:Luteinizing Hormone / Q000378:metabolism*; D046911:Macromolecular Substances; D008297:Male; D009919:Orchiectomy; D010052:Ovariectomy; D010903:Pituitary Gland, Anterior / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D015719:Single-Strand Specific DNA and RNA Endonucleases
D046911:Macromolecular Substances; D012333:RNA, Messenger; D007265:Inhibins; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone; D004720:Endonucleases; D015719:Single-Strand Specific DNA and RNA Endonucleases