Effect of Clomiphene Citrate on Estrus Cycle and The Ova Shed in the Ovary of Female Sprague Dawley Rats

Abstract

Purpose: Clomiphene citrate (CC) is used in the management of infertile females. Estrus Cycle indices are good parameters for evaluating reproductive changes, while actual ova shed represents evidence of ovulation. This study is aimed at investigating how different doses of CC can affect the Estrus Cycle (EC), Estrus Cycle Ratio, (ECR), and ova shed (OS) in adult female rats. 
 Methodology: Twenty-five (50) female Sprague Dawley (SD) rats were divided into 5 groups. Group A was controlled while groups B, C, D, and E were treated groups. Group A received 0.5 ml of sterile water. Groups B, C, and D were given 0.2 mg/kg, 2 mg/kg, and 4 mg/kg respectively at diestrus. Group E was given 6mg/kg/day of CC dissolved in sterile water. The administration was done orally. A vaginal smear was evaluated for various estrus phases. ECR was calculated, and ova shed at the estrus phase was evaluated at autopsy. All data were presented as mean ± standard error of the mean (SEM). Statistical significance was taken at P < 0.05
 Findings: There was a significant decrease (p<0.05) in the number of proestrus, estrus, metestrus, and diestrus in treated groups compared with control. ECR value in all treated groups also decreased significantly (p<0.05) when compared with control. This study further shows that all the animal groups (A-E) released ova but there was a significant decrease (p<0.05) in the number of ova released in groups B, C, D, and E against the control group.
 Conclusion: CC decreases EC. It reduced ECR, hence prolonging luteogenesis. It decreases the number of eggs released. With a large dose and prolonged use, eggs were still released even when the ova released and counted were fewer compared with when this drug was not in use. 
 Recommendation: Infertile couples should copulate more at the luteal phase of the menstrual cycle when on CC to increase their chances of pregnancy. CC decreases the number of eggs released but makes the few eggs released stay longer for fertilization.