Polychlorinated biphenyls (PCBs) affect the hypothalamic-pituitary-gonadal axis in many vertebrates, changing the hormonal regulation of reproduction. To identify one of the possible sites of action of PCBs on gonadotropin release in common carp, the direct effects of Aroclor 1254 on luteinizing hormone (LH) secretion from dispersed pituitary cells were investigated. Pituitary cells were obtained from sexually mature male and female common carp (Cyprinus carpio L.) at the time of natural spawning. The cells were incubated with different concentrations of Aroclor 1254 (5, 10, 50 and 100 ng mL⁻¹ medium) and/or salmon gonadotropin-releasing hormone analogue (sGnRHa) at a concentration of 10⁻⁸ M. LH levels were measured in the cultured medium by the ELISA method after 10 hours of cell incubation. Incubation of male pituitary cells in the presence of tested concentrations of Aroclor did not change the basal LH secretion to the media. In the female pituitary cell incubations Aroclor (5, 10 and 100 ng mL⁻¹ medium) caused a significant increase in LH concentrations in comparison to control incubations. In the case of sGnRHa-stimulated LH secretion in incubations of cells of both sexes, all the concentrations of Aroclor significantly stimulated LH release and potentiated stimulatory effects of sGnRH analogue. These results indicate that endocrine disrupters, such as Aroclor 1254, may affect reproduction in fish, acting also directly on gonadotrophs at the level of the pituitary gland, changing LH secretion.

中文翻译：

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Aroclor 1254对基础和sGnRHa刺激的鲤鱼垂体细胞LH分泌的性别依赖性作用。

多氯联苯（PCBs）影响许多脊椎动物的下丘脑-垂体-性腺轴，从而改变了激素对生殖的调节。为了确定多氯联苯对鲤鱼促性腺激素释放的可能作用部位之一，研究了Aroclor 1254对分散的垂体细胞促黄体生成激素（LH）分泌的直接作用。在自然产卵时从具有性成熟的雄性和雌性鲤鱼（Cyprinus carpio L.）中获得垂体细胞。将细胞与浓度为10 ^-8的不同浓度的Aroclor 1254 （5、10、50和100 ng mL ^-1培养基）和/或鲑鱼促性腺激素释放激素类似物（sGnRHa）孵育细胞温育10小时后，通过ELISA法测量培养基中的M.LH水平。在测试浓度的Aroclor存在下孵育男性垂体细胞不会改变基础LH向培养基的分泌。在女性垂体细胞培养中，Aroclor（5、10和100 ng mL ^-1培养基）导致LH浓度与对照培养相比显着增加。在男女性别细胞培养中受sGnRHa刺激的LH分泌的情况下，所有浓度的Aroclor均可显着刺激LH释放并增强sGnRH类似物的刺激作用。这些结果表明，内分泌干扰物，例如Aroclor 1254，可能会影响鱼类的繁殖，并直接作用于垂体水平的促性腺激素，从而改变LH的分泌。