Study on double reciprocal innervation of the iris dilator muscle and sphincter muscle by a whole cell patch-clump technique

近年来，应用组织化学、药理学、生理学等技术研究发现，虹膜扩张肌和括约肌均受交感神经和副交感神经双重支配。本研究应用全细胞斑片-细胞团技术研究了虹膜肌细胞、扩张肌和括约肌的双重相互神经支配。在此之前，我们培养了扩张器和括约肌细胞，以获得相当数量的同质材料。用免疫组织化学方法对肌细胞进行染色。培养细胞表面较平，细胞膜较脆。虽然它们不完全适合于实验，但我们记录了所选细胞的静息膜电位。结果表明，该电位较低，为0 ~-5mV，电刺激不能记录到动作电位。根据Watanabe等人（1），在生理条件下，神经或括约肌短脉冲直接电刺激均不会引起膜电位的任何变化。它属于低兴奋性平滑肌，如气管、主动脉和肺动脉。我们的结果似乎支持他们的结论。肌肉的低兴奋性是由于去极化引起的内向电流（Ca^<2+>电流）和外向电流（K^+电流）之间的平衡（4，5）。平滑肌细胞膜兴奋性的多样性是最近才发现的。虹膜平滑肌的性质与我们先前的假设大不相同。我们计划首先发展虹膜肌细胞膜Ca^<2+>电流的研究主题。关于扩张肌，据我们所知，还没有关于斑块技术的报道。

It is well-known that both the iris dilator muscle and the sphincter muscle are innervated doublely by the sympathetic and parasympathetic nerves by recent research applied the histochemical, pharmacological, physiological techniques. The purpose of this study is to investigate the double reciprocal innervation of the iris muscle cells, the dilator and the sphincter muscle by means of a whole cell patch-clump technique. Preceding the study we cultured the dilator and the sphincter cells to get considerable amonuts of the homogenous materials. Proof of the muscle cells was done with immunohistochemical method. The surface of the cultured cells was rather flat and the membrane was fragile. Although they were not fully suitable for the experiment, we recorded the resting membrane potential in the selected cells. It was found to be low, 0 to-5 mV.The action potential could not be record by the electrical stimulation. According to Watanabe et al (1) neither nerve nor direct electrical stimulation with short pulses of the sphincter nuscle elicited any changes in the membrane potential under physiological conditions. It belongs to a low-excitability smooth muscle such as the trachea, aorta and pulmonary artery. Our results appears to support their conclusion. The low-excitability of the muscle is due to the balance between the inward current (Ca^<2+> current) and the outward current (K^+ current) elicited by depolarization (4,5). Diversity of membrane excitability in smooth muscle has become recently known. The nature of the iris smooth muscles is quite different from what we previously assumed. We plan first to develop our theme for the investigation of Ca^<2+> current of the iris muscle cell membrane. Concerning the dilator muscle, as far as we know , there is no report on patch-clump technique.