INVOLVEMENT OF DOPAMINE D1 RECEPTORS IN THE CONTROL OF GROWTH-HORMONE SECRETION IN THE RAT
INVOLVEMENT OF DOPAMINE D1 RECEPTORS IN THE CONTROL OF GROWTH-HORMONE SECRETION IN THE RAT
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DOI：
10.1677/joe.0.1270191
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发表时间：
1990-11-01
影响因子：
4
通讯作者：
KORDON, C
中科院分区：
文献类型：
--
作者：
BLUETPAJOT, MT;MOUNIER, F;KORDON, C
多巴胺对GH释放的影响进行了研究，在体内自由活动的完整大鼠和大鼠下丘脑病变，并在体外的灌注系统中使用分散的雄性大鼠垂体细胞保持在原代培养。在体内，多巴胺（5毫克/公斤体重）引起的快速和非常短暂的增加，血浆GH水平在病变，但不是在完整的大鼠。预先注射D1拮抗剂SCH 23390（0.5 mg/kg）可显著抑制该增加，但未注射D2拮抗剂多潘立酮（0.5 mg/kg）。D1激动剂SKF 38393诱导损伤大鼠GH释放的剂量依赖性刺激，SCH 23390（0.5 mg/kg）预处理可消除5 mg/kg剂量下获得的效应。在体外，多巴胺（0.1 μ mol/l）和SKF 38393（0.1 μ mol/l）引起灌流大鼠垂体细胞快速、可逆地释放GH;同时灌流SCH 23390（1 μ mol/l）可显著抑制该效应。这些结果表明，多巴胺可以刺激垂体水平的基础GH的释放，这种刺激是由D1，而不是由D2受体介导的。他们还支持了未鉴定的下丘脑神经激素可能调节这种作用的假设。
The effects of dopamine on GH release were investigated both in vivo in freely moving intact rats and in rats with a mediobasal hypothalamic lesion, and in vitro in a perifusion system using dispersed male rat pituitary cells kept in primary culture. In vivo, dopamine (5 mg/kg body weight) induced a rapid and very transient increase in plasma GH levels in lesioned but not in intact rats. This increase was markedly inhibited by a prior injection of the D1 antagonist SCH 23390 (0.5 mg/kg) but not of the D2 antagonist domperidone (0.5 mg/kg). The D1 agonist SKF 38393 induced a dose-dependent stimulation of GH release in lesioned rats, and the effect obtained with a dose of 5 mg/kg was abolished by pretreatment with SCH 23390 (0.5 mg/kg). In vitro, dopamine (0.1 .mu.mol/l) and SKF 38393 (0.1 .mu.mol/l) provoked a rapid and reversible release of GH from superfused rat pituitary cells; this effect was markedly inhibited by simultaneous superfusion of SCH 23390 (1 .mu.mol/l). These findings indicate that dopamine can stimulate basal GH release at the pituitary level and that this stimulation is mediated by D1 but not by D2 receptors. They also support the hypothesis that unidentified hypothalamic neurohormones may modulate this effect.