Differences in the Follicular Morphology of Young and Aged Bitches and Their Correlation with the Anti-Müllerian Hormone

Abstract

This study aimed to investigate the structural, morphological and cellular differences of follicles at different stages of follicular development as well as to determine the correlation of the ovarian follicle population with serum Anti-Mullerian Hormone (AMH) levels in young and aged bithches. Sixteen bitches were divided into two groups according to their ages. Group A included young bitches aged 2 years (n=8) while Group B constituted of those aged 8 to 10 years (n=8). Diameters of the primordial, primary and preantral follicles were found to be significantly larger in Group B, in comparison to Group A. In Group A, the mean number of granulosa cells was 91.65±2.23 in the secondary follicles and 301.31±4.16 in the preantral follicles. In Group B, the same values were found to be 89.46±2.68 and 270.25±3.54, respectively. The mean serum AMH levels in Group A and Group B were 0.233±0.046 ng/mL and 0.099±0.008 ng/mL, respectively (P<0.05). In conclusion, the results indicated that the number of primordial and primary follicles as well as the numbers of granulosa cells in secondary and preantral follicles decreased with advanced age which resulted in lower serum AMH levels in aged bitches. The results suggested that the AMH, which is used as a fertility parameter in humans, could also be used for the same purpose in dogs.