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Vincent P Markowski - One of the best experts on this subject based on the ideXlab platform.

  • Research | Article Perinatal Exposure to Low Levels of the Environmental Antiandrogen Vinclozolin Alters Sex-Differentiated Social Play and Sexual Behaviors in the Rat
    2013
    Co-Authors: Nathan K W Colbert, Nicole C Pelletier, Joyce M Cote, Nicole Jurdak, Sara B Minott, John B. Concannon, Vincent P Markowski
    Abstract:

    In this study we examined the effects of exposure to the antiandrogenic fungicide vinclozolin (Vz) on the development of two sex-differentiated behaviors that are organized by the perinatal actions of androgens. Pregnant Long-Evans rats were administered a daily oral dose of 0, 1.5, 3, 6, or 12 mg/kg Vz from the 14th day of gestation through postnatal day (PND)3. The social play behavior of juvenile offspring was examined on PND22 and again on PND34 during play sessions with a same-sex littermate. After they reached adulthood, the male offspring were examined with the ex copula Penile Reflex procedure to assess erectile function. Vz did not produce any gross maternal or neonatal toxicity, nor did it reduce the anogenital distance in male pups. We observed no effects of Vz on play behavior on PND22. However, the 12-mg/kg Vz dose significantly increased play behavior in the male offspring on PND34 compared with controls. The most dramatic increases were seen with the nape contact and pounce behavior components of play. The Vz effect was more pronounced in male than in female offspring. As adults, male offspring showed a significant reduction of erections at all dose levels during the ex copula Penile Reflex tests. The 12-mg/kg dose was also associated with an increase in seminal emissions. These effects demonstrate that perinatal Vz disrupts the development of androgen-mediated behavioral functions at exposure levels that do not produce obvious structural changes or weight reductions in androgensensitive reproductive organs. Key words: antiandrogen, Penile Reflexes, prenatal exposure, rat, social play, vinclozolin. Environ Health Perspect 113:700–707 (2005). doi:10.1289/ehp.7509 available vi

  • perinatal exposure to low levels of the environmental antiandrogen vinclozolin alters sex differentiated social play and sexual behaviors in the rat
    Environmental Health Perspectives, 2005
    Co-Authors: Nathan K W Colbert, Nicole C Pelletier, Joyce M Cote, John Concannon, Nicole Jurdak, Sara B Minott, Vincent P Markowski
    Abstract:

    In this study we examined the effects of exposure to the antiandrogenic fungicide vinclozolin (Vz) on the development of two sex-differentiated behaviors that are organized by the perinatal actions of androgens. Pregnant Long-Evans rats were administered a daily oral dose of 0, 1.5, 3, 6, or 12 mg/kg Vz from the 14th day of gestation through postnatal day (PND)3. The social play behavior of juvenile offspring was examined on PND22 and again on PND34 during play sessions with a same-sex littermate. After they reached adulthood, the male offspring were examined with the ex copula Penile Reflex procedure to assess erectile function. Vz did not produce any gross maternal or neonatal toxicity, nor did it reduce the anogenital distance in male pups. We observed no effects of Vz on play behavior on PND22. However, the 12-mg/kg Vz dose significantly increased play behavior in the male offspring on PND34 compared with controls. The most dramatic increases were seen with the nape contact and pounce behavior components of play. The Vz effect was more pronounced in male than in female offspring. As adults, male offspring showed a significant reduction of erections at all dose levels during the ex copula Penile Reflex tests. The 12-mg/kg dose was also associated with an increase in seminal emissions. These effects demonstrate that perinatal Vz disrupts the development of androgen-mediated behavioral functions at exposure levels that do not produce obvious structural changes or weight reductions in androgen-sensitive reproductive organs.

Michael S. Beattie - One of the best experts on this subject based on the ideXlab platform.

  • Intrathecal methiothepin and thyrotropin-releasing hormone effects on Penile erection.
    Physiology & Behavior, 2001
    Co-Authors: Gregory M. Holmes, Jacqueline C. Bresnahan, Robert L. Stephens, Michael S. Beattie
    Abstract:

    Intrathecal thyrotropin-releasing hormone (TRH) potently inhibits Penile erection at all doses (100, 500, 1000 or 5000 pmol) tested so far. Since the serotonin receptor antagonist methiothepin (MT) inhibits TRH responses in other systems, this study tested the hypothesis that MT-sensitive receptors mediate the effect of TRH on Penile erection in rats. When compared to controls, the highest doses of IT TRH (0, 10 or 500 pmol) or MT (5 or 50 nmol) significantly altered Penile Reflex latency. When coadministered (50 nmol MT/500 pmol TRH), the effect of TRH was reversed, suggesting that the high dose of MT antagonized the inhibitory actions of TRH. The low dose of MT (5 nmol) did not block the 500 pmol TRH inhibition of Reflex latency. These data further suggest that MT sensitive receptors are important in (1) mediating normal Penile Reflexes and (2) mediating the inhibitory response to TRH.

  • Differential effects of intrathecal thyrotropin-releasing hormone (TRH) on perineal Reflexes in male rats
    Physiology & behavior, 1997
    Co-Authors: Gregory M. Holmes, Richard C. Rogers, Jacqueline C. Bresnahan, Michael S. Beattie
    Abstract:

    The effects of thyrotropin-releasing hormone (TRH) on the sexual and defecatory Reflexes regulated by pudendal motoneurons were investigated. Intrathecal TRH (10 μl volume; 0.0, 0.01, 1.0, or 100 μM concentration) at lumbosacral spinal segments (L4-S1) in acute preparations produced a dose-dependent increase in external anal sphincter (EAS), but not bulbospongiosus (BS), electromyographic (EMG) activity. Intraspinal (L6) injection of 100 μM TRH (1 μl/micropipette), significantly increased EAS EMG activity in acute preparations. Electromyographic activity of the BS muscle was unchanged. All doses of intrathecal TRH (10 μl volume; 0, 10, 50, 100, or 500 μM concentration) in awake animals significantly reduced the proportion of responders to a Penile Reflex test. Subsequently, all measures of Penile Reflexes were significantly reduced. Glans tumescence and defecation bouts before or during Penile Reflex testing were unaffected by intrathecal TRH as were indices of behavioral and motor hyper-reactivity analogous to that produced by serotonin. These data indicate that pudendal motoneurons, in the dorsomedial nucleus, are differentially regulated by neuropeptides present in the lumbosacral spinal cord.

Nathan K W Colbert - One of the best experts on this subject based on the ideXlab platform.

  • Research | Article Perinatal Exposure to Low Levels of the Environmental Antiandrogen Vinclozolin Alters Sex-Differentiated Social Play and Sexual Behaviors in the Rat
    2013
    Co-Authors: Nathan K W Colbert, Nicole C Pelletier, Joyce M Cote, Nicole Jurdak, Sara B Minott, John B. Concannon, Vincent P Markowski
    Abstract:

    In this study we examined the effects of exposure to the antiandrogenic fungicide vinclozolin (Vz) on the development of two sex-differentiated behaviors that are organized by the perinatal actions of androgens. Pregnant Long-Evans rats were administered a daily oral dose of 0, 1.5, 3, 6, or 12 mg/kg Vz from the 14th day of gestation through postnatal day (PND)3. The social play behavior of juvenile offspring was examined on PND22 and again on PND34 during play sessions with a same-sex littermate. After they reached adulthood, the male offspring were examined with the ex copula Penile Reflex procedure to assess erectile function. Vz did not produce any gross maternal or neonatal toxicity, nor did it reduce the anogenital distance in male pups. We observed no effects of Vz on play behavior on PND22. However, the 12-mg/kg Vz dose significantly increased play behavior in the male offspring on PND34 compared with controls. The most dramatic increases were seen with the nape contact and pounce behavior components of play. The Vz effect was more pronounced in male than in female offspring. As adults, male offspring showed a significant reduction of erections at all dose levels during the ex copula Penile Reflex tests. The 12-mg/kg dose was also associated with an increase in seminal emissions. These effects demonstrate that perinatal Vz disrupts the development of androgen-mediated behavioral functions at exposure levels that do not produce obvious structural changes or weight reductions in androgensensitive reproductive organs. Key words: antiandrogen, Penile Reflexes, prenatal exposure, rat, social play, vinclozolin. Environ Health Perspect 113:700–707 (2005). doi:10.1289/ehp.7509 available vi

  • perinatal exposure to low levels of the environmental antiandrogen vinclozolin alters sex differentiated social play and sexual behaviors in the rat
    Environmental Health Perspectives, 2005
    Co-Authors: Nathan K W Colbert, Nicole C Pelletier, Joyce M Cote, John Concannon, Nicole Jurdak, Sara B Minott, Vincent P Markowski
    Abstract:

    In this study we examined the effects of exposure to the antiandrogenic fungicide vinclozolin (Vz) on the development of two sex-differentiated behaviors that are organized by the perinatal actions of androgens. Pregnant Long-Evans rats were administered a daily oral dose of 0, 1.5, 3, 6, or 12 mg/kg Vz from the 14th day of gestation through postnatal day (PND)3. The social play behavior of juvenile offspring was examined on PND22 and again on PND34 during play sessions with a same-sex littermate. After they reached adulthood, the male offspring were examined with the ex copula Penile Reflex procedure to assess erectile function. Vz did not produce any gross maternal or neonatal toxicity, nor did it reduce the anogenital distance in male pups. We observed no effects of Vz on play behavior on PND22. However, the 12-mg/kg Vz dose significantly increased play behavior in the male offspring on PND34 compared with controls. The most dramatic increases were seen with the nape contact and pounce behavior components of play. The Vz effect was more pronounced in male than in female offspring. As adults, male offspring showed a significant reduction of erections at all dose levels during the ex copula Penile Reflex tests. The 12-mg/kg dose was also associated with an increase in seminal emissions. These effects demonstrate that perinatal Vz disrupts the development of androgen-mediated behavioral functions at exposure levels that do not produce obvious structural changes or weight reductions in androgen-sensitive reproductive organs.

Gregory M. Holmes - One of the best experts on this subject based on the ideXlab platform.

  • Intrathecal methiothepin and thyrotropin-releasing hormone effects on Penile erection.
    Physiology & Behavior, 2001
    Co-Authors: Gregory M. Holmes, Jacqueline C. Bresnahan, Robert L. Stephens, Michael S. Beattie
    Abstract:

    Intrathecal thyrotropin-releasing hormone (TRH) potently inhibits Penile erection at all doses (100, 500, 1000 or 5000 pmol) tested so far. Since the serotonin receptor antagonist methiothepin (MT) inhibits TRH responses in other systems, this study tested the hypothesis that MT-sensitive receptors mediate the effect of TRH on Penile erection in rats. When compared to controls, the highest doses of IT TRH (0, 10 or 500 pmol) or MT (5 or 50 nmol) significantly altered Penile Reflex latency. When coadministered (50 nmol MT/500 pmol TRH), the effect of TRH was reversed, suggesting that the high dose of MT antagonized the inhibitory actions of TRH. The low dose of MT (5 nmol) did not block the 500 pmol TRH inhibition of Reflex latency. These data further suggest that MT sensitive receptors are important in (1) mediating normal Penile Reflexes and (2) mediating the inhibitory response to TRH.

  • Differential effects of intrathecal thyrotropin-releasing hormone (TRH) on perineal Reflexes in male rats
    Physiology & behavior, 1997
    Co-Authors: Gregory M. Holmes, Richard C. Rogers, Jacqueline C. Bresnahan, Michael S. Beattie
    Abstract:

    The effects of thyrotropin-releasing hormone (TRH) on the sexual and defecatory Reflexes regulated by pudendal motoneurons were investigated. Intrathecal TRH (10 μl volume; 0.0, 0.01, 1.0, or 100 μM concentration) at lumbosacral spinal segments (L4-S1) in acute preparations produced a dose-dependent increase in external anal sphincter (EAS), but not bulbospongiosus (BS), electromyographic (EMG) activity. Intraspinal (L6) injection of 100 μM TRH (1 μl/micropipette), significantly increased EAS EMG activity in acute preparations. Electromyographic activity of the BS muscle was unchanged. All doses of intrathecal TRH (10 μl volume; 0, 10, 50, 100, or 500 μM concentration) in awake animals significantly reduced the proportion of responders to a Penile Reflex test. Subsequently, all measures of Penile Reflexes were significantly reduced. Glans tumescence and defecation bouts before or during Penile Reflex testing were unaffected by intrathecal TRH as were indices of behavioral and motor hyper-reactivity analogous to that produced by serotonin. These data indicate that pudendal motoneurons, in the dorsomedial nucleus, are differentially regulated by neuropeptides present in the lumbosacral spinal cord.

Joyce M Cote - One of the best experts on this subject based on the ideXlab platform.

  • Research | Article Perinatal Exposure to Low Levels of the Environmental Antiandrogen Vinclozolin Alters Sex-Differentiated Social Play and Sexual Behaviors in the Rat
    2013
    Co-Authors: Nathan K W Colbert, Nicole C Pelletier, Joyce M Cote, Nicole Jurdak, Sara B Minott, John B. Concannon, Vincent P Markowski
    Abstract:

    In this study we examined the effects of exposure to the antiandrogenic fungicide vinclozolin (Vz) on the development of two sex-differentiated behaviors that are organized by the perinatal actions of androgens. Pregnant Long-Evans rats were administered a daily oral dose of 0, 1.5, 3, 6, or 12 mg/kg Vz from the 14th day of gestation through postnatal day (PND)3. The social play behavior of juvenile offspring was examined on PND22 and again on PND34 during play sessions with a same-sex littermate. After they reached adulthood, the male offspring were examined with the ex copula Penile Reflex procedure to assess erectile function. Vz did not produce any gross maternal or neonatal toxicity, nor did it reduce the anogenital distance in male pups. We observed no effects of Vz on play behavior on PND22. However, the 12-mg/kg Vz dose significantly increased play behavior in the male offspring on PND34 compared with controls. The most dramatic increases were seen with the nape contact and pounce behavior components of play. The Vz effect was more pronounced in male than in female offspring. As adults, male offspring showed a significant reduction of erections at all dose levels during the ex copula Penile Reflex tests. The 12-mg/kg dose was also associated with an increase in seminal emissions. These effects demonstrate that perinatal Vz disrupts the development of androgen-mediated behavioral functions at exposure levels that do not produce obvious structural changes or weight reductions in androgensensitive reproductive organs. Key words: antiandrogen, Penile Reflexes, prenatal exposure, rat, social play, vinclozolin. Environ Health Perspect 113:700–707 (2005). doi:10.1289/ehp.7509 available vi

  • perinatal exposure to low levels of the environmental antiandrogen vinclozolin alters sex differentiated social play and sexual behaviors in the rat
    Environmental Health Perspectives, 2005
    Co-Authors: Nathan K W Colbert, Nicole C Pelletier, Joyce M Cote, John Concannon, Nicole Jurdak, Sara B Minott, Vincent P Markowski
    Abstract:

    In this study we examined the effects of exposure to the antiandrogenic fungicide vinclozolin (Vz) on the development of two sex-differentiated behaviors that are organized by the perinatal actions of androgens. Pregnant Long-Evans rats were administered a daily oral dose of 0, 1.5, 3, 6, or 12 mg/kg Vz from the 14th day of gestation through postnatal day (PND)3. The social play behavior of juvenile offspring was examined on PND22 and again on PND34 during play sessions with a same-sex littermate. After they reached adulthood, the male offspring were examined with the ex copula Penile Reflex procedure to assess erectile function. Vz did not produce any gross maternal or neonatal toxicity, nor did it reduce the anogenital distance in male pups. We observed no effects of Vz on play behavior on PND22. However, the 12-mg/kg Vz dose significantly increased play behavior in the male offspring on PND34 compared with controls. The most dramatic increases were seen with the nape contact and pounce behavior components of play. The Vz effect was more pronounced in male than in female offspring. As adults, male offspring showed a significant reduction of erections at all dose levels during the ex copula Penile Reflex tests. The 12-mg/kg dose was also associated with an increase in seminal emissions. These effects demonstrate that perinatal Vz disrupts the development of androgen-mediated behavioral functions at exposure levels that do not produce obvious structural changes or weight reductions in androgen-sensitive reproductive organs.