Willoughby J O, Brazeau P, Martin J B
Endocrinology. 1977 Oct;101(4):1298-303. doi: 10.1210/endo-101-4-1298.
Growth hormone (rGH) and prolactin (rPRL) secretory profiles were obtained before and after treatment with a dopamine receptor blocking agent, (+) butaclamol, in 10 male rats chronically implanted with right atrial cannulae. Mean rGH plasma concentrations, determined by planimetry, were reduced (202 +/- 20 ng/ml vs. 135 +/- 20ng/ml, P less than .01), but the basic configuration and periodicity of rGH secretory bursts were unaltered. Mean rPRL plasma concentrations were elevated (11.1 +/- 2.1 ng/ml vs 65.5 +/- 8.1 ng/ml, P less than .0005), but rPRL episodic secretion was still apparent. It is concluded that dopaminergic neurons have a minor role in facilitating episodic rGH secretion. Furthermore, persisting episodic rPRL secretion in rats administered a dopamine antagonist suggests that rPRL feedback inhibition does not inactivitate the neural mechanism generating episodic rPRL secretion.
对10只长期植入右心房插管的雄性大鼠，在用多巴胺受体阻断剂（+）布他拉莫治疗前后，获取生长激素（rGH）和催乳素（rPRL）的分泌情况。通过平面测量法测定的rGH平均血浆浓度降低（202±20 ng/ml对135±20 ng/ml，P＜0.01），但rGH分泌脉冲的基本形态和周期性未改变。rPRL平均血浆浓度升高（11.1±2.1 ng/ml对65.5±8.1 ng/ml，P＜0.0005），但rPRL的间歇性分泌仍很明显。得出的结论是，多巴胺能神经元在促进rGH间歇性分泌中作用较小。此外，给予多巴胺拮抗剂的大鼠中持续存在的rPRL间歇性分泌表明，rPRL的反馈抑制并未使产生rPRL间歇性分泌的神经机制失活。
