Considerable attention has been focused on environmental disruptors such as the xenoestrogen bisphenol A, which influencesreproductive, developmental, and cognitive activities through itsinteraction with specific neuromediating systems in an estrogen-like fashion. In the present study, the effects of this xenoestrogenproved to be preferentially directed toward hypothalamic and extrahypothalamic somatostatin receptor subtype 3, which displayed a higher binding affinity of its specific nonpeptide agonist L-796-778 than that of L-779–976 (subtype 2). One type of action, with respect to animals treated with vehicle alone, consisted of a very strong (p < 0.001) decrease of somatostatin receptor subtype 3 mRNA levels in layer V of the frontoparietal cortex of adult rats (Sprague-Dawley) after transplacental and lactational exposure to bisphenol A (400 microg/kg/day). Similarly, such treatment in 7-day-old rats was responsible for a very strong reduction of the subtype 3 mRNA levels in the hypothalamic periventricular nuclei and a strong (p < 0.01) increase of the subtype 3 mRNA levels in the ventromedial nuclei. Moreover, even greater upregulated and downregulated activities were reported when subtype 3 mRNA levels were determined in the presence of receptor agonists specific for distinct alpha GABAA receptor subunits (alpha1,5). The predominant effects of bisphenol A on somatostatin receptor subtype 3 mRNA levels occurring in an alpha GABAA subunit–dependent manner tend to suggest the early modulatory importance of this environmental disruptor on cross-talking mechanisms that are implicated in the plasticity of neural circuits, with consequential influence on neuroendocrine/sociosexual behaviors.
Neurobiological effects of bisphenol A may be mediated by somatostatin subtype 3 receptors in some regions of the developing rat.
FACCIOLO R. M.
;ALO' R.;CANONACO M.;
2005-01-01
Abstract
Considerable attention has been focused on environmental disruptors such as the xenoestrogen bisphenol A, which influencesreproductive, developmental, and cognitive activities through itsinteraction with specific neuromediating systems in an estrogen-like fashion. In the present study, the effects of this xenoestrogenproved to be preferentially directed toward hypothalamic and extrahypothalamic somatostatin receptor subtype 3, which displayed a higher binding affinity of its specific nonpeptide agonist L-796-778 than that of L-779–976 (subtype 2). One type of action, with respect to animals treated with vehicle alone, consisted of a very strong (p < 0.001) decrease of somatostatin receptor subtype 3 mRNA levels in layer V of the frontoparietal cortex of adult rats (Sprague-Dawley) after transplacental and lactational exposure to bisphenol A (400 microg/kg/day). Similarly, such treatment in 7-day-old rats was responsible for a very strong reduction of the subtype 3 mRNA levels in the hypothalamic periventricular nuclei and a strong (p < 0.01) increase of the subtype 3 mRNA levels in the ventromedial nuclei. Moreover, even greater upregulated and downregulated activities were reported when subtype 3 mRNA levels were determined in the presence of receptor agonists specific for distinct alpha GABAA receptor subunits (alpha1,5). The predominant effects of bisphenol A on somatostatin receptor subtype 3 mRNA levels occurring in an alpha GABAA subunit–dependent manner tend to suggest the early modulatory importance of this environmental disruptor on cross-talking mechanisms that are implicated in the plasticity of neural circuits, with consequential influence on neuroendocrine/sociosexual behaviors.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.