LA BOVINA DA LATTE COME MODELLO PER LO STUDIO DEL PRECOCE INVECCHIAMENTO OVARICO: ASPETTI MORFOLOGICI E MOLECOLARI.

Several studies in women indicate that precocious ovarian aging is a disorder characterized by an accelerated decline of reproductive potential. We demonstrated that ovaries recovered from 4-8 years old dairy cows with a low antral follicle count generate oocytes with low developmental competence, high aneuploidy rate after maturation, a reduced amount of active mitochondria and a lower glutathione synthesis capability. Interestingly, these ovaries have a reduced volume, show a low proportion of healthy primordial follicles and an increased stromal tissue. Moreover this is accompanied by reduced perifollicular vessels and endothelial nitric oxide (NO) synthase concentration. Interestingly, the administration of NO donor molecules partially reverse the defective oocyte developmental capability in vitro. Finally, follicular fluids recovered from these ovaries have a high progesterone concentration, low estrogen/progesterone ratio and low Anti-Mullerian hormone concentration, which accounts for a low follicle reserve. Altogether, morphological changes, ovarian and endocrine functions consistently indicate a condition of precocious ovarian failure in young adult dairy cows and validate the use of this population as an animal model to study the accelerated decline of fertility in women.