Sjöblom-Widfeldt N, Nilsson H
Department of Physiology, University of Göteborg, Sweden.
Acta Physiol Scand. 1989 Apr;135(4):505-11. doi: 10.1111/j.1748-1716.1989.tb08609.x.
In the present study we examine the calcium requirements of the neurogenic response in vitro of small arteries (150-200 microns diameter) from the mesentery of Wistar rats. Intramural nerves were activated with electrical field stimulation. Responses to single impulses and to low-frequency repeated stimulation were reduced or abolished by reducing the Ca2+ concentration in the bathing solution from 2.5 to 1.0 mM. Responses to higher frequencies (16 Hz) were only slightly affected. Since calcium reduction had markedly less effect on responses to direct activation of the smooth muscle and on responses to any dose of exogenous noradrenaline, the calcium reduction had mainly pre-junctional effects. The data show that part of the neurogenic response is highly calcium-sensitive, perhaps more so than would be expected of a purely noradrenergic transmission.
在本研究中，我们检测了来自Wistar大鼠肠系膜的小动脉（直径150 - 200微米）体外神经源性反应的钙需求。通过电场刺激激活壁内神经。将浴液中的Ca2+浓度从2.5 mM降至1.0 mM可使对单个冲动和低频重复刺激的反应减弱或消失。对较高频率（16 Hz）的反应仅受到轻微影响。由于钙减少对平滑肌直接激活的反应以及对外源去甲肾上腺素任何剂量的反应影响明显较小，所以钙减少主要具有节前效应。数据表明，部分神经源性反应对钙高度敏感，可能比单纯的去甲肾上腺素能传递所预期的更为敏感。
