원문정보
초록
영어
It is generally accepted that chronic stress impairs female reproduction. It negatively affect ovarian function and the number of ovulated oocytes. Chronic stress lower the number of retrieved oocytes. Ovarian follicular development is regulated by both pituitary-derived gonadotropins and intraovarian regulatory factors. The main corticosteroids are cortisol, cortisone, 11-deoxycortisol and corticosterone, cortisol being one of the most commonly used welfare and stress physiological indicator. In this study, we investigated the effect of cortisol level on progesterone patterns and the number of ovulated oocytes in the dog. Blood samples were collected and progesterone levels were analyzed for determining ovulation time via radioimmunoassay. At the same time, serum cortisol level was measured. The day of ovulation was considered as the day when serum progesterone level was 6.0～8.0 ng/ml. In vivo matured dog oocytes were collected using flushing oviducts of mixed-breed bitches at three days after ovulation. We classified dogs as having higher cortisol level (over 8 μg/dL), medium cortisol level (4～7 μg/dL), and lower corisol level (1～3 μg/dL). The patterns of progesterone was not different in all cortisol groups. The average numbers of retrieved oocytes was not different in all cortisol groups. 9 in higher cortisol level (over 8 μg/dL), 9.5 in medium cortisol level (4～7 μg/dL), and 9.6 in lower corisol level (1～3 μg/dL). The effects of high cortisol on the competence of oocytes and steroid hormone patterns will be studied.