Alterations in the insulin pathway in the ovary of cows with induced follicular persistence

GAREIS, N.C.; STASSI, A; RODRIGUEZ F; CATTANEO, L; MOREYRA ML; SALVETTI NR; ORTEGA, H.H; HEIN, G.J.; REY F

Mar del Plata

Congreso; LXIII Reunión Científica Anual de la Sociedad Argentina de Investigación Clínica (SAIC); 2018

Sociedad Argentina de Investigación Clínica

Several local factors, including componentsof the insulin pathway, are involved in the ovarian follicular persistenceassociated with anovulation. In previous studies,we detected alterations of insulin-signaling intermediaries in the ovaries from cows with cystic ovarian disease.Therefore, we aimed to study the protein expressionof IR, IRS1, PI3K, total and phosphorylated AKT by immunohistochemistry inovarian follicular structures from a model of follicular persistence. We also measuredthe insulin concentrations in serum and follicular fluid by radioimmunoassay. The model was performed with an intravaginalprogesterone device to get subluteal concentrations of progesterone, obtainingdominant follicles in the expected day of ovulation (n=5; P0) and folliclesthat persist for 5 (n=5; P 5), 10 (n=5; P10) or 15 days (n=5; P15) relative tothe expected time of ovulation. Controls cows were ovariectomized in proestrus(n=5; C). Serum insulin concentrations werehigher in all persistence groups than in control cows and the intrafollicularconcentrations were higher in P5, P10 and P15 groups respect to the controlgroup (p<0.05). In granulosa cells, the expression of IR was higher indominant follicles of control group relative to all persistent folliclesevaluated (p<0.05). In theca cells, the expression of IR was higher inpersistent follicles of P0 and P5 groups respect to persistent follicles of P10and P15 groups (p<0.05). While in granulosa, the IRS1 was higher in thedominant follicles than in persistent follicles of P5 and P15 groups (p<0.05),the expression in theca cells showed no differences (p>0.05). The PI3K andphosphorylated AKT were higher in control group than all persistence groups inboth cell populations (p<0.05). Total AKT expression showed no differences (p>0.05).Alterations of the insulin-signaling in follicularpersistence could be involved in a lower insulin response that might beassociated with disorders in ovarian functionality.