Peripubertal development of noradrenergic stimulation of luteinizing hormone-releasing hormone neurosecretion in vitro.
Peripubertal development of noradrenergic stimulation of luteinizing hormone-releasing hormone neurosecretion in vitro.
复制标题
体外去甲肾上腺素能刺激黄体生成素释放激素神经分泌的青春期围发育。
DOI：
10.1016/0006-8993(88)91302-9
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发表时间：
1988
期刊：
影响因子：
2.9
通讯作者：
Sladek,CD
中科院分区：
文献类型：
--
作者：
Clough,RW;Hoffman,GE;Sladek,CD
本研究探讨了年龄对去甲肾上腺素（NE）刺激下丘脑视前区-基底内侧区（POA-MBH）外植体分泌促黄体生成激素释放激素（LH-RH）的影响。从幼年（9日龄）、青春期前（29日龄）和成年雌性大鼠中获得外植体。断头和手术分离后，POA-MBH外植体分别用培养基灌注，收集用于LH-RH放射免疫测定。将外植体暴露于含NE（5 × 10− 4 M，峰值浓度）的培养基的两个脉冲和含KCl（45 mM，峰值浓度）的培养基的终末脉冲，以评估活力。青春期前雌性大鼠POA-MBH外植体在两次NE脉冲和随后的KCl脉冲刺激下，LH-RH释放增加（P< 0.05）。NE对9日龄雌性大鼠POA-MBH神经元LH-RH分泌无明显刺激作用，但对KCl有明显刺激作用（P< 0.01）。用苯甲酸雌二醇（EB）对9日龄和青春期前大鼠进行为期两天的预处理，未改变青春期前雌性大鼠外植体对该剂量NE或KCl（无组或相互作用效应）的LH-RH反应，也未使9日龄大鼠的外植体对NE反应。此外，NE是同样有效地刺激LH-RH释放从外植体从雌二醇治疗或控制卵巢切除成年大鼠。这些观察结果表明，青春期周围激活NE对LH-RH释放的刺激作用，从POA-MBH外植体在体外。虽然这些数据也表明，雌激素是不是强制性的NE刺激从POA-MBH外植体的LH-RH释放，需要进一步的调查，以确定发展的时间进程和去甲肾上腺素刺激LH-RH神经分泌的雌激素依赖性，并评估是否雌激素改变POA-MBH外植体的敏感性，以较低浓度的NE，如先前报道的中位数隆起片段。
The effect of age on norepinephrine (NE) stimulation of luteinizing hormone-releasing hormone (LH-RH) secretion from preoptic area-mediobasal hypothalamic (POA-MBH) explants was examined in the present study. Explants were obtained from juvinile (9-day-old), prepubertal (29-day-old) and adult female rats. Following decapitation and surgical isolation, POA-MBH explants were individually perifused with culture medium which was collected for radioimmunoassay of LH-RH. Explants were exposed to two pulses of medium containing NE (5 × 10−4M, peak concentration) and a terminal pulse of medium containing KCl (45 mM, peak concentration) for assessment of viability. POA-MBH explants obtained from prepubertal female rats exhibited increased LH-RH release in response to the two pulses of NE and subsequent KCl pulse (P< 0.05). NE was without effect in stimulating LH-RH neurosecretion from POA-MBH explants obtained from 9-day-old female rats although these explants were responsive to KCl (P< 0.01). Two-day pretreatment of 9-day-old, and prepubertal rats with estradiol benzoate (EB) did not alter the LH-RH response to this dose of NE or KCl (no group or interaction effects) in prepubertal female rat explants and did not render the explants from 9-day-old rats responsive to NE. Furthermore, NE was equally effective in stimulating LH-RH release from explants obtained from estradiol-treated or control ovariectomized adult rats. These observations demonstrate a peripubertal activation of the stimulatory effect of NE on LH-RH release from POA-MBH explants in vitro. Although these data also suggest that estrogen is not obligatory for NE stimulation of LH-RH release from POA-MBH explants, further investigation is required to determine the developmental time course and estrogen dependency of the noradrenergic stimulation of LH-RH neurosecretion and to evaluate whether estrogen alters the sensitivity of POA-MBH explants to lower concentrations of NE as has been previously reported for median eminence fragments.