Limits...
Methylmercury inhibits prolactin release in a cell line of pituitary origin.

Maués LA, Macchi BM, Crespo-López ME, Nasciutti LE, Picanço-Diniz DL, Antunes-Rodrigues J, Nascimento JL - Braz. J. Med. Biol. Res. (2015)

Bottom Line: Heavy metals, such as methylmercury, are key environmental pollutants that easily reach human beings by bioaccumulation through the food chain.Several reports have demonstrated that endocrine organs, and especially the pituitary gland, are potential targets for mercury accumulation; however, the effects on the regulation of hormonal release are unclear.Interestingly, inhibition of nitric oxide synthase by N-nitro-L-arginine completely prevented the decrease in prolactin release without acute neurotoxic effects of methylmercury.

View Article: PubMed Central - PubMed

Affiliation: Laboratório de Neuroquímica Molecular e Celular, Instituto de Ciências Biológicas, Universidade Federal do Pará, Belém, PA, Brasil.

ABSTRACT
Heavy metals, such as methylmercury, are key environmental pollutants that easily reach human beings by bioaccumulation through the food chain. Several reports have demonstrated that endocrine organs, and especially the pituitary gland, are potential targets for mercury accumulation; however, the effects on the regulation of hormonal release are unclear. It has been suggested that serum prolactin could represent a biomarker of heavy metal exposure. The aim of this study was to evaluate the effect of methylmercury on prolactin release and the role of the nitrergic system using prolactin secretory cells (the mammosomatotroph cell line, GH3B6). Exposure to methylmercury (0-100 μM) was cytotoxic in a time- and concentration-dependent manner, with an LC50 higher than described for cells of neuronal origin, suggesting GH3B6 cells have a relative resistance. Methylmercury (at exposures as low as 1 μM for 2 h) also decreased prolactin release. Interestingly, inhibition of nitric oxide synthase by N-nitro-L-arginine completely prevented the decrease in prolactin release without acute neurotoxic effects of methylmercury. These data indicate that the decrease in prolactin production occurs via activation of the nitrergic system and is an early effect of methylmercury in cells of pituitary origin.

No MeSH data available.


Related in: MedlinePlus

Prolactin release by the rat pituitary cell line GH3B6 exposed to differentmethylmercury (MeHg) concentrations for 2 h (top panel) or 6 h(bottom panel). Data are reported as means ± SE (n=6).*P<0.05, **P<0.01, and ***P<0.001 vs control;#P<0.05 vs the 1-μM group (ANOVA with Tukey'stest).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4541687&req=5

f01: Prolactin release by the rat pituitary cell line GH3B6 exposed to differentmethylmercury (MeHg) concentrations for 2 h (top panel) or 6 h(bottom panel). Data are reported as means ± SE (n=6).*P<0.05, **P<0.01, and ***P<0.001 vs control;#P<0.05 vs the 1-μM group (ANOVA with Tukey'stest).

Mentions: All MeHg concentrations significantly decreased prolactin release from GH3B6 cells(Figure 1). Incubation for 2 h resulted inlower levels of prolactin release than 6 h of incubation. MeHg inhibition ofprolactin release was evident even at the lowest concentration (1 μM; P<0.001).After 6 h of MeHg exposure, a significant difference (P<0.05) was detected betweenthe 1- and 10-μM MeHg-treated groups (Figure 1,bottom panel).


Methylmercury inhibits prolactin release in a cell line of pituitary origin.

Maués LA, Macchi BM, Crespo-López ME, Nasciutti LE, Picanço-Diniz DL, Antunes-Rodrigues J, Nascimento JL - Braz. J. Med. Biol. Res. (2015)

Prolactin release by the rat pituitary cell line GH3B6 exposed to differentmethylmercury (MeHg) concentrations for 2 h (top panel) or 6 h(bottom panel). Data are reported as means ± SE (n=6).*P<0.05, **P<0.01, and ***P<0.001 vs control;#P<0.05 vs the 1-μM group (ANOVA with Tukey'stest).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4541687&req=5

f01: Prolactin release by the rat pituitary cell line GH3B6 exposed to differentmethylmercury (MeHg) concentrations for 2 h (top panel) or 6 h(bottom panel). Data are reported as means ± SE (n=6).*P<0.05, **P<0.01, and ***P<0.001 vs control;#P<0.05 vs the 1-μM group (ANOVA with Tukey'stest).
Mentions: All MeHg concentrations significantly decreased prolactin release from GH3B6 cells(Figure 1). Incubation for 2 h resulted inlower levels of prolactin release than 6 h of incubation. MeHg inhibition ofprolactin release was evident even at the lowest concentration (1 μM; P<0.001).After 6 h of MeHg exposure, a significant difference (P<0.05) was detected betweenthe 1- and 10-μM MeHg-treated groups (Figure 1,bottom panel).

Bottom Line: Heavy metals, such as methylmercury, are key environmental pollutants that easily reach human beings by bioaccumulation through the food chain.Several reports have demonstrated that endocrine organs, and especially the pituitary gland, are potential targets for mercury accumulation; however, the effects on the regulation of hormonal release are unclear.Interestingly, inhibition of nitric oxide synthase by N-nitro-L-arginine completely prevented the decrease in prolactin release without acute neurotoxic effects of methylmercury.

View Article: PubMed Central - PubMed

Affiliation: Laboratório de Neuroquímica Molecular e Celular, Instituto de Ciências Biológicas, Universidade Federal do Pará, Belém, PA, Brasil.

ABSTRACT
Heavy metals, such as methylmercury, are key environmental pollutants that easily reach human beings by bioaccumulation through the food chain. Several reports have demonstrated that endocrine organs, and especially the pituitary gland, are potential targets for mercury accumulation; however, the effects on the regulation of hormonal release are unclear. It has been suggested that serum prolactin could represent a biomarker of heavy metal exposure. The aim of this study was to evaluate the effect of methylmercury on prolactin release and the role of the nitrergic system using prolactin secretory cells (the mammosomatotroph cell line, GH3B6). Exposure to methylmercury (0-100 μM) was cytotoxic in a time- and concentration-dependent manner, with an LC50 higher than described for cells of neuronal origin, suggesting GH3B6 cells have a relative resistance. Methylmercury (at exposures as low as 1 μM for 2 h) also decreased prolactin release. Interestingly, inhibition of nitric oxide synthase by N-nitro-L-arginine completely prevented the decrease in prolactin release without acute neurotoxic effects of methylmercury. These data indicate that the decrease in prolactin production occurs via activation of the nitrergic system and is an early effect of methylmercury in cells of pituitary origin.

No MeSH data available.


Related in: MedlinePlus