Regulation of testicular LH/hCG receptors in golden hamsters (Mesocricetus auratus) during development.

During prepubertal development in the golden hamster, there are major age-related changes in the number of testicular LH/hCG receptors. Between 22 and 35 days of age, there was greater than 10-fold increase in testicular LH/hCG receptors, followed by a decrease at Day 37. Concomitant with, but preceding slightly, the changes in receptors, were increases in plasma LH and FSH and most noticeably prolactin concentrations, between Days 10 and 20 of age. Inhibition of the increases in plasma levels of prolactin by daily injections of bromocriptine, between 14 and 31 days of age, resulted in suppressed testicular and seminal vesicle weights, and decreased content and concentration of testicular LH/hCG receptors. Similarly, the premature increase in plasma prolactin concentrations in prepubertal hamsters between 6 and 20 days of age, by means of ectopic pituitary transplants, resulted in increased testicular and seminal vesicle weights, as well as an increase in the concentration of testicular LH/hCG receptors. These results strongly suggest that increases in plasma prolactin values during development are important in enhancement of the development of testicular LH/hCG receptors.