Changes in the volume and histology of focus of endometriosis in rats treated with sinvastatin - Revista Brasileira de Ginecologia e Obstetrícia

PURPOSE: to analyze the macroscopic and histological changes that occur with the use of sinvastatin in experimental endometriosis in female rats. METHODS: forty Wistar female rats were submitted to the technique of uterine self-transplant in mesenterium. After three weeks, 24 of them developed experimental endometriosis grade III, and were divided in two groups: one group received sinvastatin orally (20 mg/kg/day) and the other (control group) received 0.9% of sodium chloride orally (1 mL/100 g of body weight/day). Both groups received gavage for 14 days, followed by death. The implant volume was calculated [4pi (lenght/2) x (width/2) x (height/2)/3] at the surgical intervention and after the animal’s death. The self-transplants were removed, dyed with hematoxylin-eosin and analyzed by light microscopy. The Mann-Whitney’s test was used in the independent samples and the Wilcoxon’s test for the related samples. The Fisher’s exact test was used for the histological evaluation, with a significance level of 5%. RESULTS: the difference between groups of the initial average volumes of the self-transplants was not significant (p=1.00), but became significant for the final average volumes (p=0.04). There was a significant increase (p=0.01) between the initial and final average volumes in the control group, and a no significant decrease in the sinvastatin group (p=0.95). Histologically, the sinvastatin group (n=9) presented seven cases (77.8%) of moderately preserved and two cases (22.2%) of well preserved epithelial wall, while the control group (n=12) presented seven cases (58.3%) of moderately preserved and five cases (41.7%) of well preserved epithelial wall. CONCLUSIONS: sinvastatin prevented the growth of experimental endometriosis. Studies with sinvastatin for longer periods are promising.