Immunoneutralization of inhibin suppresses reproduction in female mink.

This study determined whether immunoneutralization of inhibin affected gonadotropin secretion, embryo development, and ovarian function in mink. Adult female mink (n = 10) were immunized with bovine inhibin alpha’�6 gly-tyr (btNH, 100 �g) conjugated to human alpha globulins (HAG), or with HAG alone (n = 10, controls), mixed with Freund’s complete adjuvant. A series of five boosters containing btNH or HAG were then administered during a 2-yr period. Titers of bINH antibodies and serum concentrations of gonadotropins were determined for each breeding season in 1990 and 1991. Each year after whelping, we determined gestation length; sex, number, and weight of live and dead kits per litter at birth; and number and weight of kits per litter 3 wk after whelping. Results were pooled for statistical analysis. Bovine INH antibody titers (percent “tI-bINH bound to serum diluted 1:8000) were 53 ± 3% vs. 2 ± 0.6%, and serum concentrations of FSH were higher (p 0.05) in bINil-immunized mink compared with controls. We conclude that inhibin has a key role in regulation of FSH secretion and may have a physiological role important for embryo development and survival in mink.