Anti-Mullerian hormone (AMH) secretion in prepubertal and adult rams

The aim of the present analysis was to determine whether anti-Mullerian hormone concentrations in prepubertal plasma or adult rete testis fluid are related to the number or function of Sertoli cells in rams or to the presence of the Fec(B) Booroola gene. Twenty rams from two Booroola crosses, differing in their testicular masses were analysed; in each cross, half of the animals were heterozygous carriers of the Fec(B) gene. The data from rams, during prepuberty and at adulthood during the non-sexual season, were analysed by two-way ANOVA and residual correlations. In 4-week-old intact male lambs, the mean anti-Mullerian hormone plasma concentration was 15 ng ml(-1), irrespective of cross, genotype or eCG stimulation; it was significantly negatively correlated with FSH (r = -0.51; P = 0.02; n = 19). In adults, anti-Mullerian hormone was not detectable in plasma and was 0.5 ng ml(-1) in rete testis fluid, irrespective of cross or genotype. The total number of Sertoli cells per testis was not related to anti-Mullerian hormone concentration in lamb prepubertal plasma or in adult rete testis fluid. The concentration of anti-Mullerian hormone in adult rete testis fluid was significantly and negatively correlated with the daily production of leptotene primary spermatocytes per testis (r = -0.56; P = 0.02; n = 16). The mean oestrogen concentration in the adult testicular vein was 2 pg ml(-1) and was correlated negatively with the rete testis fluid concentration of anti-Mullerian hormone (r = -0.60; P = 0.02; n = 15) and correlated positively with the daily production of leptotene primary spermatocytes per testis (r = 0.53; P < 0.05; n = 19). In conclusion, anti-Mullerian hormone secretion was not correlated with the total numbers of Sertoli cells per testis and cannot be used as a predictor of the number of Sertoli cells. Anti-Mullerian hormone secretions were not affected by the presence of Fec(B) gene. However, anti-Mullerian hormone secretion could be considered to be inversely related to the daily production of primary spermatocytes by the testis.