The effect of neurointermediate lobe denervation on hypothalamic neuroendocrine dopaminergic neurons
The effect of neurointermediate lobe denervation on hypothalamic neuroendocrine dopaminergic neurons
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DOI：
10.1016/s0006-8993(98)00740-9
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发表时间：
1998-09-21
期刊：
影响因子：
2.9
通讯作者：
Freeman, ME
中科院分区：
文献类型：
--
作者：
DeMaria, JE;Zelena, D;Freeman, ME
结节垂体区和脑室周围-垂体区多巴胺能神经元对催乳素(PRL)分泌的调节作用尚不清楚。在这项研究中，我们使用脑垂体柄压迫来干扰下丘脑对神经中间叶(NIL)的神经输入。神经中间叶去神经术(NIL-D)选择性地破坏结节-垂体区和脑室周围-垂体区多巴胺能神经元的轴突，而保留漏斗状区多巴胺能神经元和垂体腺的血管供应。对去卵巢(OVX)大鼠进行NIL-D治疗。用高效液相色谱-电化学法测定OVX和OVX+NIL-D大鼠正中隆起(ME)和脑垂体区3，4-二羟基苯乙酸(DOPAC)的浓度，放射免疫法测定血清催乳素(PRL)、α-黑素细胞刺激素(α-MSH)和黄体生成素(LH)的浓度。通过增加水摄入量证实了NIL-D的成功。NIL-D治疗后1周，血清PRL、α-MSH水平升高，而血清LH水平无明显变化。DA在正中隆起(ME)升高，在前叶外区(AL-OZ)、中间叶(IL)和神经叶(NL)降低，在前叶内区(AL-IZ)无明显变化。在去卵巢大鼠中，去甲肾上腺素和去甲氧胆碱使去甲肾上腺素和去甲肾上腺素的DOPAC浓度升高，而在去甲肾上腺素和去甲氧西林的去甲肾上腺去神经作用不变，提示去卵巢大鼠去卵巢后，去甲肾上腺素对去卵巢大鼠PRL和α-MSH的分泌有明显的抑制作用。(C)1998 Elsevier Science B.V.保留所有权利。
The contribution of tuberohypophyseal and periventricular-hypophyseal dopaminergic neurons to the regulation of the secretion of prolactin (PRL) has yet to be clarified. In this study, we used pituitary stalk compression to disrupt hypothalamic neural input to the neurointermediate lobe (NIL). Neurointermediate lobe denervation (NIL-D) selectively disrupts the axons of tuberohypophyseal and periventricular-hypophyseal dopaminergic neurons, while leaving tuberoinfundibular dopaminergic neurons and the vascular supply of the pituitary gland intact. NIL-D was performed in ovariectomized (OVX) rats. The concentration of DA and 3,4-dihydroxyphenylacetic acid (DOPAC) in the median eminence (ME) and various regions of the pituitary gland of OVX and OVX + NIL-D rats were measured by HPLC-EC, The concentration of PRL, alpha-melanocyte stimulating hormone (alpha-MSH), and luteinizing hormone (LH) in serum were determined by radioimmunoassay. Successful NIL-D was confirmed by increased water intake. One week after NIL-D, serum PRL and alpha-MSH were elevated, but there was no change in the concentration of LH in serum. The concentration of DA was increased in the median eminence (ME), decreased in the outer zone of the anterior lobe (AL-OZ), as well as the intermediate (IL) and neural lobes (NL), and remained unchanged in the inner zone of the anterior lobe (AL-IZ). The concentration of DOPAC was increased in the ME and NL, decreased in the IL, and remained unchanged in both the AL-IZ and AL-OZ, These data confirm that pituitary stalk compression denervates the NIL, Moreover, decreases in the concentration of DA in the IL and AL-OZ, coupled with elevation of serum PRL and alpha-MSH indicate that DA from the NIL contributes to the increased inhibition of the secretion of PRL and alpha-MSH in OVX rats. (C) 1998 Elsevier Science B.V. All rights reserved.