Radioimmunoassay of mouse vas deferens protein: developmental profile and hormonal regulation

This study investigated the hormonal regulation of the developmental pattern of a major protein of the mouse vas deferens (MVDP) which represents 10% of the vas deferens protein content. Using a specific radioimmunoassay, MVDP was first detected in 10-day-old males and its concentration increased sharply between 10 and 30 days, reaching adult levels at 40 days. In adult males, MVDP disappeared after castration, and testosterone treatment for 15 days was necessary to reverse the effect of castration completely. In 10-day-old mice castrated at birth, MVDP levels were similar to those measured in controls of the same age. Testosterone administration from 1 to 10 days of age did not induce precocious accumulation of MVDP. These results suggested that the neonatal expression of MVDP is independent of androgens. From 10 to 30 days, the increase in MVDP levels was androgen-dependent as shown by the castration and injection experiments. In males castrated at birth, the androgen-induced accumulation of MVDP was greatly reduced in adulthood. This suggested that neonatal androgens are necessary to obtain full expression of the MVDP gene in adults.