Sex hormones including progesterons, androgens, and estrogens are influential in differentiation of ovarian tissues and competence of fertility. These steroid hormones derived from cholesterol are required for cumulus-oocyte complexes(COCs) during oocyte maturation. COCs is a total functional and active entity playing a central role in oocyte. Lipid metabolism in the mammalian COCs is controlled by environmental factors. The intracellular cholesterol contents go through remarkable changes. It plays an important part of oocyte developmental competence.
However, heat stress affects steroid hormone by decreasing progesterone, estrogen concentrations, and resumption of meiosis in COCs maturation. Reduction of the hormone and meiotic resumption might lead to the decline of ovarian function, follicle maturation, and subsequent embryogenesis. In the same vein, heat stress also influence on germinal vesicle breakdown, lipolytic variations, and loss of the nuclear envelope in the course of maturation of oocytes.
In summary, we examined the effects of thermal stress on oocyte maturation through steroid hormone contents of change identifying the molecular mechanisms of lipids metabolism. It may have the solution to further the therapy methods for disorders regarding sterility.