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

ABSTRACT 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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    ABSTRACT: Doramectin (DOR) is an antiparasitic drug that is widely used in domestic animals. In mammals, DOR act as a γ-aminobutyric acid receptor agonist. This neurotransmitter plays an important role in the regulation of sexual behavior. The present study investigated the effects of two medically relevant doses of DOR on sexual behavior in male rats. We also examined whether previous sexual experience modulates responses to DOR. General activity was first observed in an open field 24, 48, and 72h after administration of 0.1 and 0.3mg/kg DOR to determine the dose and time effects of the drug. Apomorphine-induced penile erection and sexual behavior in inexperienced male rats were then analyzed. The effects of previous sexual experience on subsequent sexual behavior in DOR-treated rats (0.3mg/kg, 24h prior to the test) were also assessed. The standard therapeutic dose (0.2mg/kg) did not modify general activity or penile erection. A slightly concentrated dose of 0.3mg/kg, which is still within the therapeutic range, decreased apomorphine-induced penile erection, whereas 0.2mg/kg did not modify this behavior. Compared with controls, sexual behavior in inexperienced male rats was impaired after 0.3mg/kg DOR. Previous sexual experience had little impact on the effects of 0.3mg/kg DOR. In conclusion, the 0.2mg/kg dose of DOR did not affect motor behavior or apomorphine-induced penile erection. At a more at a slightly higher dose level, the appetitive and consummatory phases of sexual behavior in inexperienced male rats was impaired. Previous sexual experience was unable to reverse this sexual impairment, suggesting that previous sexual experience does not exert a positive effect in attenuating sexual impairment produced by DOR treatment.
    Neurotoxicology and Teratology 07/2013; 39. DOI:10.1016/ · 2.76 Impact Factor
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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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    ABSTRACT: Ivermectin (IVM) is an antiparasitic drug, widely used in domestic animals. In mammals, IVM act as a GABA agonist. This neurotransmitter has an important role in the regulation of sexual behavior. Thus, this study sought to investigate the effects of various medically relevant doses IVM on the sexual behavior of male rats. In particular, we also wished to examine if previous sexual experience modulated responses to IVM. In the first experiment, the sexual behavior of inexperienced male rats was analyzed after they received 0.2, 0.6, 1.0 or 2.0 mg/kg IVM, 15 min prior to behavioral testing. In the second experiment, the effects of four previous sexual experiences on IVM treated rats (1.0 or 2.0 mg/kg, 15 min prior to the 5th session) were assessed. The standard therapeutic dose (0.2 mg/kg) did not impair the sexual behavior of inexperienced male rats. At a more concentrated dose (0.6 mg/kg), which is still within the therapeutic range, the appetitive phase of sexual behavior of inexperienced male rats was impaired. Likewise, 1.0 mg/kg impaired the appetitive phase. Previous sexual experience blocked almost entirely this sexual impairment, suggesting that previous sexual experience exerts a positive effect in attenuating the sexual impairment produced by IVM treatment. Therefore, the standard therapeutic dose of IVM can be used without producing side effects on sexual behavior. Use of more concentrated therapeutic doses is not recommended during reproductive periods, unless the animals have had previous sexual experience.
    Research in Veterinary Science 08/2011; 91(1):77-81. DOI:10.1016/j.rvsc.2010.07.026 · 1.41 Impact Factor
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    ABSTRACT: In this study, we prepared microscale periodic rough structures consisting of parallel strips on a silicon surface. The width of each strip was equal to the gap between the strips, and the silicon surface was silanized with perfluorooctyltrichlorosilane. We studied the wetting characteristics of water drops as they advanced and receded on patterned surfaces in a direction perpendicular to the strip. Water drops were observed to advance or recede in a smooth manner when the strip width was smaller than 32 microm but in a stick-jump manner when the strip width was larger than 50 microm. The regular strip-patterned substrates enabled us to deduce the relationship between the stick-jump behavior and the feature size of the substrate. For surfaces on which water drops showed stick-jump behavior, the oscillation amplitude of the contact angle decreased with decreasing strip width. In addition, the jumping distances of the contact lines, for both advancing and receding water drops, were nearly equal to the strip period. A 2D model was applied to analyze the contact line motion on the patterned surfaces, which showed reasonable agreement with the experimental results.
    Langmuir 04/2009; 25(5):3212-8. DOI:10.1021/la803801y · 4.46 Impact Factor
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