Comparative study on induction and effects of surgical menopause in a female rat model: a prospective case control study.

OBJECTIVE To compare induced surgical menopause in rat models following hysterectomy with ovarian preservation, unilateral or bilateral oophorectomy, versus control. Secondary objective was evaluation of certain physiological changes in the animal following the induced menopause. DESIGN A prospective case control study. SETTING University Research Centre. METHODOLOGY 80 female rats were divided into four groups (n=20). HG: hysterectomy with ovarian preservation, UOG: unilateral oophorectomy, BOG: bilateral oophorectomy and CG: control rats. Blood tests were done at day 0, one week and one month post-procedure for hormonal profile including FSH and E2, and lipid profile including cholesterol, LDL and HDL. Behavioral tests (Learning and memory tests) were also done. RESULTS Menopause was successfully induced by the three used surgical methods. After one week, no significant difference in FSH level between CG and HG. But its level was significantly increased in BOG and UOG. E2 level was significantly decreased in HG, UOG and BOG in comparison to CG. Its level in BOG was significantly lower than that of UOG and HG. Cholesterol level was significantly higher in HG, UOG and BOG in comparison to CG, also its level was significantly increased in UOG and BOG in comparison to HG (P<0.001). Long term memory was affected in BOG and UOG, one week and one month post-menopausal induction in comparison to the control. CONCLUSION surgical menopause, induced by hysterectomy alone, unilateral, or bilateral oophorectomy has a negative impact on reproductive hormonal function, as well as cognitive & cardiovascular integrity. We suggest a possibility of early ovarian failure after hysterectomy alone or with unilateral oophorectomy.