Kahle G, Kaulen P, Wollensak J
Universitätsklinikum Rudolf Virchow, Standort Charlottenburg, Berlin.
Fortschr Ophthalmol. 1990;87(1):105-9.
In the present study beta-adrenergic receptors were identified and localized by autoradiographic methods using [125I]cyanopindolol in human eyes, as well as in the eyes of marmosets and albino rabbits. Quantification revealed that the highest binding-site densities are in the ciliary body and the corneal epithelium and endothelium. Moreover, the iris and conjunctiva showed significant amounts of specific [125I]cyanopindolol binding. In pigmented human and marmoset eyes, binding to the ciliary epithelium and iris was not inhibited by 10 microM propranolol, thus representing nonspecific binding sites. In nonpigmented rabbit eyes, binding to all parts of the eye was reduced to the level of background by 10 microM propranolol and 100 nM ICI 118-551, which is a highly selective beta 2-adrenergic ligand. Being selective for serotonin1B receptors, 100 nM ICI 89-406 which blocks more than 95% of the beta 1-adrenergic receptors, and RU 24,969 have no effect on [125I]cyanopindolol binding, which suggests that there is binding to beta 2-adrenergic receptors. The anatomical location and quantification of beta 2-receptors in the mammalian eye may contribute to better understanding of beta 2-adrenoceptor function and the action of beta-adrenoceptor blocking agents in glaucoma therapy.
在本研究中，使用[125I]氰基吲哚洛尔通过放射自显影方法在人眼以及狨猴和白化兔的眼中鉴定并定位了β-肾上腺素能受体。定量分析显示，最高的结合位点密度存在于睫状体、角膜上皮和内皮中。此外，虹膜和结膜显示出大量特异性的[125I]氰基吲哚洛尔结合。在有色人种和狨猴的眼睛中，10微摩尔普萘洛尔不会抑制与睫状上皮和虹膜的结合，因此代表非特异性结合位点。在无色素的兔眼中，10微摩尔普萘洛尔和100纳摩尔ICI 118 - 551（一种高度选择性的β2 - 肾上腺素能配体）可将与眼睛所有部位的结合降低至背景水平。作为5-羟色胺1B受体的选择性抑制剂，可阻断超过95%的β1 - 肾上腺素能受体的100纳摩尔ICI 89 - 406和RU 24,969对[125I]氰基吲哚洛尔结合没有影响，这表明存在与β2 - 肾上腺素能受体的结合。哺乳动物眼中β2受体的解剖位置和定量分析可能有助于更好地理解β2 - 肾上腺素能受体功能以及β - 肾上腺素能受体阻断剂在青光眼治疗中的作用。
