Influencia del ciclo lunar y estral en el diámetro de folículos antrales y cuerpos lúteos en cobayas nulíparas

Abstract

This study analyzed the influence of the lunar cycle and the phases of the estrous cycle on the diameter of antral follicles and corpus luteum in nulliparous guinea pigs. Vaginal cytology and histological sections of ovaries obtained from previous research were used. The antral follicles of each ovary were observed under an inverted microscope and photographed with a digital camera attached to the microscope. After taking the measurements, the antral follicles were classified as small, medium, large, and very large. The data were organized in spreadsheets, and the effects of the lunar phase and phases of the estrous cycle were analyzed using SAS statistical software, applying generalized linear mixed models. The results showed that the average diameter of the antral follicles varied between 185.1 and 212.7 between phases of the lunar cycle without statistical differences (P>0.05). Although the lunar phase did not affect follicle diameter (P= 0.1065); it influenced the follicular categories (P>0.0001); the interaction between lunar phase and follicular category (P= 0.0008) were highly significant. In medium (P= 0.7828) and large (P= 0.8039) antral follicles, no statistical significance was observed between lunar phases; however, the lunar phase affected the size of small (P= 0.0292) and very large (P= 0.0006) antral follicles. In relation to the estrous cycle, the average antral follicle size varied between 176.15 and 227.31 µm, with no statistical differences between phases (P= 0,5107). Although the effect of follicular category was highly significant (P < 0.0001), the interaction between estrous cycle phases x follicular category was not (P= 0.9110), so that comparisons of each category also did not vary between estrous cycle phases (P > 0.05). The diameter of the corpus luteum did not vary between phases of the lunar cycle or phases of the estrous cycle (P > 0.005). It is concluded that only the diameter of small and very large antral follicles was affected by the lunar phase.