Ivermectin does not interfere with seminal and hormonal parameters in male rabbits.


Graduate Program of Experimental and Comparative Pathology, Department of Pathology, School of Veterinary Medicine and Animal Science, University of São Paulo, Av. Prof. Dr. Orlando Marques de Paiva, 87, São Paulo, SP, 05508-270, Brazil. Electronic address: [Email]


Ivermectin (IVM) is a macrocyclic lactone used as a broad spectrum antiparasitic agent against nematodes and arthropods. It is mainly used in the control of parasitic infections of domestic animals, and recently has been used in humans to treat onchocerciasis, scabies, and pediculosis. In mammals, evidence has indicated that macrocyclic lactones interact with gamma-aminobutyric acid (GABA)-mediated chloride channels. The GABAergic system is known to be involved in the manifestation of sexual behavior, and previous studies have shown that IVM impaired sexual behavior in both male and female rats. Thus, considering that IVM may interfere with the sexual sphere, this study evaluated the temporal (1 up 60 days) effects of exposure to IVM (0.2 and 1.0 mg/kg, administered subcutaneously) on seminal and hormonal parameters of male rabbits. In male rabbits, the spermatozoa concentration, motility and morphology, the integrity of the plasmatic, acrosomal and mitochondrial membranes of the spermatozoa, the organ weights, gonadosomatic index, serum testosterone concentrations, histopathological findings were evaluated and hematological and serum biochemical analysis was conducted. No changes were observed in male seminal parameters evaluated by spermatozoa concentration, motility, and morphology, nor the potential for fertilization evaluated by the integrity of the plasmatic, acrosomal, and mitochondrial membranes of the spermatozoa; there was also no interference in serum testosterone concentration, serum biochemistry and hematological parameters. The findings of this study using the artificial vagina for collection of semen and computer-assisted semen analysis showed that IVM at doses of 0.2 and 1.0 mg/kg of SC did not alter any of the semen parameters of rabbits evaluated for up to 60 days after administration.


Andrological evaluation,Avermectin,Spermatozoa characteristics,Testosterone,