Millar J C, Wilson W S, Carr R D, Humphries R G
Department of Pharmacology, University of Glasgow, Scotland.
J Ocul Pharmacol Ther. 1995 Spring;11(1):11-23. doi: 10.1089/jop.1995.11.11.
A novel technique is described in which the effect of the beta-adrenoceptor antagonists timolol and carteolol, and the vasodilators sodium nitroprusside (SNP) and verapamil on intraocular pressure (IOP) and the distribution of ocular flow in the bovine arterially perfused eye is investigated using radiolabelled microspheres. At maximum IOP-reducing dose timolol was found to significantly reduce perfusion in the choroid and, at higher dose, it was found to significantly reduce perfusion in the iris. By contrast, a maximal IOP-reducing dose of carteolol markedly reduced perfusion in the iris, ciliary body and choroid. Vasoconstriction induced by carteolol was not inhibited by the alpha-antagonist phentolamine. Against a background of vascular tone induced by noradrenaline, SNP and verapamil were found to significantly increase perfusion in the iris, ciliary body and choroid. The effects of these drugs upon the vasculature of the bovine perfused eye are varied and complex and may not bear a direct relationship to their ocular hypotensive effect.
本文描述了一种新技术，利用放射性微球研究β-肾上腺素能拮抗剂噻吗洛尔和卡替洛尔以及血管扩张剂硝普钠（SNP）和维拉帕米对牛动脉灌注眼的眼压（IOP）和眼内血流分布的影响。在最大眼压降低剂量下，发现噻吗洛尔可显著降低脉络膜灌注，而在更高剂量下，发现其可显著降低虹膜灌注。相比之下，卡替洛尔的最大眼压降低剂量可显著降低虹膜、睫状体和脉络膜的灌注。卡替洛尔诱导的血管收缩未被α-拮抗剂酚妥拉明抑制。在去甲肾上腺素诱导的血管张力背景下，发现SNP和维拉帕米可显著增加虹膜、睫状体和脉络膜的灌注。这些药物对牛灌注眼血管系统的影响是多样而复杂的，可能与其降眼压作用没有直接关系。
