A study of the circadian rhythm and pre- and postpuberty concentrations of serum prolactin in male prairie deer mice (Peromyscus maniculatus bairdii)

Abstract

The serum prolactin concentrations in 60-day-old male deer mice were measured at selected times during the day. Serum prolactin concentration, body weight, testis weight, seminal vesicle weight, and adrenal weight were also measured in males at 10, 15, 20, 30, 40, 50, 60, and 90 days of age. There was a single peak in prolactin concentration at 2100 hr, 1 hr before the onset of the light period. There were two significant peaks in serum prolactin concentration between 10 and 90 days of age: the first at 15 days and the second at 50 days of age. There was a significant positive correlation of these prolactin concentration changes with the weight increases in the body and reproductive organs over the entire 90-day period which is suggestive of a role for the hormone in the sexual maturation of males.