Background: One of the causes of infertility in women is pri- mary ovarian insufficiency (POI), which causes a decrease in follicular reserve and early menopause in women, before the age of 40. Due to the production of free radicals and oxidative stress, Cyclophosphamide (CTX) causes a decrease in follicular reserve and primary ovarian insufficiency. Due to its pleiotropic effects, Atorvastatin is widely used in the treatment of cardio- vascular diseases. In this study, the effect of Atorvastatin on ovarian tissue in rats after induction of primary ovarian insuf- ficiency (POI) by Cyclophosphamide was investigated. Materials and Methods: Twenty-four female Wistar rats were randomly divided into 4 groups: Control, POI, Atorvastatin, and POI + Atorvastatin (n=6). POI was induced by IP injection of CTX (50 mg/kg/b. w on the 1st day and 8 mg/kg/b.w for 14 consecutive days). Atorvastatin and POI+ Atorvastatin group received 10 mg/kg b.w of Atorvastatin IP injection for 10 con- secutive days. Ovaries were removed and fixed for stereologi- cal evaluations. The data were analyzed using SPSS software and one-way ANOVA and Tukey tests at a significance level of P<0.05. Results: The average volume of the total ovary, the volume of the cortex and the volume of the medulla (P<0.01) and the aver- age number of different types of follicles (P<0.001) in the POI group decreased significantly compared to the Control group. While, in the POI+atorvastatin group, there was a significant increase in the total volume of the ovary, the volume of the cortex and the volume of the medulla (P<0.05), the number of primordial and primary follicles (P<0.001), the number of pre- antral and antral follicles (Pp<0.01) in A comparison with the POI group was observed. There was no significant difference between total ovarian volume, cortex volume, medulla volume (P>0.05), and the average number of primordial and primary follicles in the POI+ Atorvastatin group compared to the Con- trol group (P>0.05). Conclusion: Atorvastatin can increase follicular reserve and improve the ovarian structure.
