Hormonal regulation of specific proteins in the rat epididymis

In the adult caput epididymidis, three specific prealbumin proteins (B2, B3, and B4) could be visualized by polyacrylamide gel electrophoresis. Castration caused the disappearance of B2 and B4, and B3 became faint. Androgen administration to castrated rat restored the protein pattern to normal. In the cauda epididymidis of the control rat, four prealbumin proteins (B1-B4) were seen of which only B3 was evident after castration. The dose of androgen administered was insufficient to restore the protein pattern of the cauda epididymidis. The caput epididymidis thus appears to have a lower androgen requirement than the cauda in regard to its protein pattern.