First evidence of allopregnanolone dose-dependent effects on preantral bovine follicles

CARDONE DA; CÁCERES ARR; SANHUEZA MA; BRUNA FA; CUELLO CARRIÓN FD; GOMEZ SE

San Juan

Congreso; XLI Reunión Científica Anual de la Sociedad de Biología de Cuyo; 2023

Allopregnanolone (ALLO) is a neurosteroid derived from progesterone. ALLO affects ovarian physiology and reproductive behavior but the study of its effects on bovine preantral follicles is limited. Ovaries from one year old heifers (n=8) were collected from a local abattoir within 30 min after the death of the animals. Ovarian cortex fragments (5 x 5 x 1 mm) were isolated with a biopsy punch and cultured for 24 hours at 37°C with different ALLO concentrations (10, 50, 100, 500, and 1000 nM) in TCM-199 culture medium. ALLO induced significant morphophysiological changes in preantral follicles. At a 1000 nM dose, there was a decrease in the number of primordial, primary (p < 0.01), and secondary follicles (p < 0.05). A significant increase in the diameter of primary follicles was observed at 50 nM and 100 nM (p < 0.01). ALLO 100 nM (p < 0.05) and 1000 nM (p < 0.01) significantly increased oocyte diameter in primordial and primary follicles. However, smaller oocyte nuclei of primordial follicles were found at 500 nM (p < 0.01). There was a significant decrease in the number of granulosa cells in primordial follicles at 10 nM and 100 nM (p < 0.001), and an increase in primary follicles at 10 nM (p < 0.001) and 1000 nM (p< 0.05). This is the first evidence of the effect of ALLO on bovine preantral follicles. ALLO exerts dose-dependent effects on morphometric parameters of preantral follicles, suggesting an important role in bovine reproductive physiology.