Moxidectin interference on sexual behavior, penile erection and hypothalamic GABA levels of male rats

Programa de Pós-Graduação em Neurociências e Comportamento, Instituto de Psicologia, Universidade de São Paulo, Brazil.
Research in Veterinary Science (Impact Factor: 1.41). 03/2008; 84(1):100-6. DOI: 10.1016/j.rvsc.2007.04.003
Source: PubMed


The moxidectin (MXD) is an antiparasitic drug used in domestic animals. The mechanism of action, in mammals, involves GABA, a neurotransmitter with an important role in the sexual behavior control. Presently, the effects of 0.2 mg/kg therapeutic dose were studied on sexual behavior, sexual motivation, penile erection and central GABA levels. Sexual behavior results showed increased latencies to the first mount and intromission as well as in inter-intromission interval; a reduction in total mounts was detected on the drug post-treatment. No difference was observed between sexual motivation of control and experimental animals. MXD treatment reduced penile erection and hypothalamic GABA levels. The results suggest that MXD reduced sexual behavior and penile erection by an action on the hypothalamic GABA system. Probably, the lack of effects in the motivational test and the increased mount and intromission latencies as well as decreased total mounts could be explained as a consequence of reduced male rat erection process.

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Available from: Helenice de Souza Spinosa, Jan 23, 2015
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    • "Muscimol and the GABA transaminase inhibitor ethanolamine-O-sulfate strongly inhibit male sexual behavior, particularly ejaculatory frequency, mounts, and intromissions (Fernandez-Guasti et al., 1986). In contrast, the stimulation of GABA B receptors appears to exert a specific effect on penile reflexes by inhibiting precopulatory behavior (Argiolas and Melis, 2005; Bitran et al., 1988; Rodrigues-Alves et al., 2008; Zarrindast and Farahvash, 1994). "
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    • "Previous studies performed in our laboratory have demonstrated that doramectin, another avermectin antiparasitic drug (Spinosa et al., 2000) and IVM (Spinosa et al., 2002) interfere with GABAergic-related behaviors, leading to anxiety and seizures, as a GABAergic agonist. Moreover, several studies have suggested that GABAergic neurotransmission is involved in inhibitory processes underlying male sexual behavior (Agmo et al., 1987; Amikishieva and Semendyaeva, 2007; Fernandez-Guasti et al., 1986; Frye and Walf, 2008; Oropeza-Hernandez et al., 2002; Rodrigues-Alves et al., 2008). Both GABA A and GABA B receptor subtypes control sexual behavior (Bitran and Hull, 1987; Frye and Paris, 2009; Paredes and Agmo, 1989, 1995). "
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