Effects of metoclopramide-induced hyperprolactinemia on the prolactin and prolactin receptor expression of murine adrenal

Abstract

The aim of this study was to evaluate the effects of metoclopramide-induced hyperprolactinemia on the prolactin (PRL) and prolactin receptor’s (PRLR) expression in the adrenal. For this purpose, a total of 12 animals with intact ovaries were allocated to two groups: G1 (saline solution) and G2 (metoclopramide). A total of 30 oophorectomized animals was randomized to five subgroups: G3 (saline solution), G4 (metoclopramide), G5 (metoclopramide + 17β-estradiol), G6 (metoclopramide + progesterone), and G7 (metoclopramide + 17β-estradiol + progesterone). Immunohistochemical analyses were evaluated semi-quantitatively. For PRLR, the area fraction of labeled cells (ALC) varied from 1 (0–10%) to 3 (> 50%). Based on the mean of the immunostaining intensity, G2 and G4 showed strong expression; G6 and G7 presented a mild reaction; and G1, G3, and G5 exhibited a weak reaction. Concerning PRL, the ALC varied from 1 (0–10%) to 3 (> 50%), and groups G6 and G7 showed a strong reaction; G2, G4, and G5 showed a mild reaction; and G1 and G3 exhibited a weak reaction. These findings suggest that metoclopramide-induced hyperprolactinemia increases PRL expression in the adrenal glands of mice. Furthermore, progesterone alone or in association with estrogen also increases PRL expression, but to a lesser extent.

Chinese abstract

本研究的目的是评估胃复安诱导的高泌乳素对肾上腺泌乳素和泌乳素受体表达的影响。为了达到这个目的，共有12个具有完整卵巢的动物被分为2组：G1(盐溶液)和G2（胃复安）。共有30个卵巢被切除的动物被随机分为5组：G3(盐溶液)，G4(胃复安)，G5(胃复安+ 17β雌二醇)，G6（胃复安+黄体酮），和G7（胃复安+17β雌二醇+黄体酮）。免疫组化分析用于半定量分析。对于泌乳素受体来说，标记细胞面积率（ALC）的变化是从1（0-10%）到3（>50%）。基于免疫染色强度的均值，G2和G4显示出强表达；G6和G7呈现出中等强度表达，G1,G3和G5反应微弱。就泌乳素而言，ALC的变化是从1（0-10%）到3（>50%），G6和G7组显示出强反应；G2,G4和G5显示出中等强度反应；G1和G3显示弱反应。这些结果表明甲氧氯普胺引起的高催乳素血症增加小鼠肾上腺的泌乳素表达。此外，单独孕激素或与孕激素与雌激素联合也增加泌乳素表达，但程度较轻。

Keywords:

• Adrenal gland
• estrogens
• hormone replacement therapy

Acknowledgements

The authors thank the Coordenacao de Apoio ao Pessoal de Nivel Superior for their financial support.

Declaration of interest

This study was supported by Coordenacao de Apoio ao Pessoal de Nivel Superior. The authors report no conflicts of interest.