Effects of Fluvoxamine on sex Steroids and oocyte ultrastructure in three spot Gourami (Trichogaster trichopterus) after increasing dopamine level by Bromocriptine injection

Background: Effect of drugs on different receptors may cause effect and also unexpected side effects.  For example, using Dopamine as an anti-parkinson drug block the upper GnRH axis and thatchr('39')s why some sexual disorders happen. In this study, the effect of serotonin as Fluvoxamine injection on lower levels of GnRH by blocking the upper GnRH axis with injection of Bromocriptine was investigated. Material & Methods: 90 pieces of three spot Gourami fish with an average weight of 3±1 were bought from the Khanmahi fish breeding center. The fish were divided into 6 groups.Three control groups: Intact control, solvent (Ethanol 70°) & Bromocriptine, and 3 treatment groups received Bromocriptine and Fluvoxamine in three doses of 1, 5 and10mg/kg.b.w. The injection was given intramuscular (IM) every other day. The fish were dissected and ovarian tissues separated for light microscope and electron microscope .After tissue fluids preparation, steroid hormones such as 17-β Estradiol, Progestrone and Testosterone were measured. Results: The results of Estradiol and Progesterone and Gonadal index showed that the groups receiving Fluvoxamine and Bromocriptine had a significant difference with the control group (P<0.005). Discussion & Conclusion: Based on the results of the higher dose of Fluvoxamine and Bromocriptine which was the predominant stage of vitellogenesis and gonadal index, it can be concluded that serotonin receptor may be present at the lower levels of the GnRH axis, and also it showed that the effect of Fluvoxamine was dose dependent.