Study of the pituitary-gonadal axis in the proestrus phase in adult female rats subjected to social isolation

ABSTRACT

Social isolation is a type of stress that might adversely affect sex cycles in both animals and humans. The present study was planned to investigate the pituitary-gonadal axis in the proestrus phase of estrous cycle in adult female rats subjected to social isolation stress for 8 weeks. Twenty Sprague-Dawley adult female rats were divided into two experimental groups a control group [n = 10] and a socially isolated group [SI, n = 10]. Throughout the study, all rats were monitored for body weight and food intake. After 8 weeks, rats were sacrificed in the proestrus phase of estrous cycle. All rats were examined for final body weight, rectal temperature, hematocrit value, and serum levels of follicle stimulating hormone, luteinizing hormones, prolactin hormone, 17-beta estradiol, and progesterone in addition to histological examination of the ovaries. The results of the present study showed that the SI group had significant decrease in their final body weights and their serum levels of 17-beta estradiol and progesterone, whereas the serum level of prolactin was significantly increased. Histological examination of SI rat ovaries showed fewer growing ovarian follicles and numerous atretic ones compared to control rat ovaries. These findings indicate that social isolation might result in depressed ovarian function in adult female rats