Effects of nicotine exposure on clomiphene citrate induced rats: morphological and immunohistochemical analysis in the ovaries

Objective: The most common use of ovulation induction in clomiphene citrate (CC) administered rats is to investigate whether there is any morphologically and immunohistochemically difference in nicotine exposure between rats not exposed to nicotine and with no CC. Materials and Methods: A total of 24 healthy rats were randomly divided into three groups: Group 1 was the group that received transdermal nicotine patched followed by clomiphene citrate. Group 2 was the only intraperitoneally CC applied group. Group 3 was the normal saline administered intraperitoneally group. On the fourth day of the cycle animals were sacrificed and bilateral salpingooophorectomy was performed. Sections were taken and stained with standard haematoxylin for histopathological examination. For immunohistochemical evaluation, sections were stained with Ki-67 and CD34. Results: There were no significant differences between the groups in terms of ovarian follicular number and types, and follicle-stroma immunohistochemical staining Ki-67 expression. There was also no significant difference in the thickness of granulosa cell between the groups. However, among the groups, CD34 expressions in group 1 were statistically less in the secondary follicle (p = 0.000), corpus luteum (p = 0.012), and more in the ovarian stroma (p = 0.001). Conclusion: In the CC-stimulated animal model, the authors did not observe that transdermal nicotine exposure was morphologically deleterious to the follicular count and types. They also could not detect the thickness of granulosa cell. Perhaps the effect on over-stimulation with CC may be less than expected, depending on the route and dose of nicotine administered.