Stjernschantz J
Glaucoma Research Laboratories, Pharmacia Ophthalmics AB, Uppsala, Sweden.
J Ocul Pharmacol. 1990 Fall;6(3):195-202. doi: 10.1089/jop.1990.6.195.
Data is presented to support a physiologic vasoconstrictor function of the parasympathetic nervous system in the anterior uvea of the eye. Studies in rabbits, cats and monkeys demonstrate that stimulation of the parasympathetic nerve fibers running with the oculomotor nerve to the eye induces a reduction in blood flow of the iris and in rabbits in the ciliary processes in addition. Pharmacologic blocking experiments indicate that most of this phenomenon is based on a cholinergic component. Since at least in rabbits mechanical factors such as stretching of the iridial tissue, a steeling phenomenon to nearby tissues of blood as well as secondary effects caused by changes in the intraocular pressure can be excluded, the reduction in blood flow in all likelihood reflects a true vasoconstriction. Experiments in unanesthetized rabbits indicate that there is a continuous physiologic cholinergic vasoconstrictor tone in the iris and ciliary processes normally. Thus, the anterior uvea in mammals may be one of the tissues exhibiting a cholinergic vasoconstriction phenomenon, found more commonly in lower vertebrates.
现提供数据以支持副交感神经系统在眼前葡萄膜的生理性血管收缩功能。对兔、猫和猴的研究表明，刺激随动眼神经走行至眼部的副交感神经纤维会导致虹膜血流量减少，此外，兔的睫状体血流量也会减少。药理学阻断实验表明，这种现象大部分基于胆碱能成分。由于至少在兔中，可以排除诸如虹膜组织拉伸、对附近组织的血液抢夺现象以及眼内压变化引起的继发效应等机械因素，血流量减少很可能反映了真正的血管收缩。对未麻醉兔的实验表明，正常情况下虹膜和睫状体存在持续的生理性胆碱能血管收缩张力。因此，哺乳动物的前葡萄膜可能是表现出胆碱能血管收缩现象的组织之一，这种现象在低等脊椎动物中更为常见。
