Watkins R W, Cummins D P, Vander Vliet G, Glennon J, Baum T
Department of Pharmacology, Schering-Plough Research Division, Bloomfield, New Jersey.
J Ocul Pharmacol. 1985 Summer;1(2):161-8. doi: 10.1089/jop.1985.1.161.
SCH 19927, the RR isomer of labetalol, has been shown to possess beta-blocking and vasodilator properties. It was compared to timolol for ability to lower intraocular pressure (IOP) in conscious rabbits. Its potential for systemic beta-blockade after topical administration was also assessed. Dose-related reductions in IOP followed topically applied SCH 19927 (0.1-1.0%). Timolol in concentrations less than 0.5% was not effective in lowering IOP. Timolol (0.1 and 0.5%) strongly inhibited tachycardia induced by iv isoproterenol. A 1.0% concentration of SCH 19927 was less effective than 0.5% timolol in inhibiting the isoproterenol-induced tachycardia; 0.1% SCH 19927 caused only minor inhibitory actions. Thus, not only is SCH 19927 at least as potent in lowering IOP in conscious rabbits, its topical administration results in less systemic beta-blockade than does timolol.
拉贝洛尔的RR异构体SCH 19927已被证明具有β受体阻断和血管舒张特性。在清醒兔中，将其与噻吗洛尔降低眼压（IOP）的能力进行了比较。还评估了局部给药后其产生全身β受体阻断作用的可能性。局部应用SCH 19927（0.1 - 1.0%）后，IOP呈剂量相关下降。浓度低于0.5%的噻吗洛尔在降低IOP方面无效。噻吗洛尔（0.1%和0.5%）强烈抑制静脉注射异丙肾上腺素引起的心动过速。1.0%浓度的SCH 19927在抑制异丙肾上腺素引起的心动过速方面比0.5%噻吗洛尔效果差；0.1%的SCH 19927仅产生轻微的抑制作用。因此，SCH 19927不仅在降低清醒兔眼压方面至少与噻吗洛尔一样有效，而且其局部给药产生的全身β受体阻断作用比噻吗洛尔小。
