Development of glycoprotein hormones and their alpha- and beta-subunits in bovine fetal pituitary glands. I. Quantitation of thyrotropin, follicle-stimulating hormone, and luteinizing hormone by radioligand receptor assays.

The development of TSH, FSH, and LH in bovine fetal pituitary glands was studied by the respective radioligand receptor assays. The content of pituitary TSH increased gradually in fetuses of both sexes throughout gestation, and no significant difference was observed for the pituitary concentration of TSH between male and female fetuses at different stages of gestation. The pituitary content of FSH increased gradually in male fetuses, but increased dramatically in female fetuses after midgestation. Similarly, the concentration of pituitary FSH was 2- to 3-fold higher in female than male fetuses after midgestation. The pituitary content of LH increased gradually and proportionally with the age of the fetus, and no significant difference was observed between sexes. However, the concentration of pituitary LH remained relatively constant for both sexes throughout gestation.