Klemfuss H, Tallarida R J, Adler C H, Adler M W
J Pharmacol Exp Ther. 1979 Jan;208(1):91-5.
The purpose of this investigation was to establish complete dose- and time-response relationships of morphine action on the rat pupil using serial observations. Adult male, albino rats of the Sprague-Dawley strain were used. Pupil size was measured by a series of photographs taken every 60 sec for at least 90 min under dim red illumination. The pupil began to dilate within 20 min after s.c. administration of doses of morphine sulfate as low as 1 mg/kg. The dose-related mydriasis reached a maximum with a dose of 32 mg/kg at 35 to 50 min after injection and lasted for 3 to 4 hr. The mydriasis was characterized by a rapid and marked fluctuation which was also dose-related and reached a peak with 32 mg/kg of morphine sulfate. Naloxone HCl (1 mg/kg) rapidly reversed both the mydriasis and the oscillation, thereby implicating an opiate receptor-mediated mechanism. In addition to providing a convenient measure of narcotic actions, the pupil may offer a particularly useful means for studying opiate receptor mechanisms since it is one of the few cases where, in many species, the anatomical pathways and neurochemical innervations are known.
本研究的目的是通过连续观察建立吗啡对大鼠瞳孔作用的完整剂量-反应和时间-反应关系。使用成年雄性Sprague-Dawley品系白化大鼠。在暗红色灯光下，每隔60秒拍摄一系列照片，持续至少90分钟，以此测量瞳孔大小。皮下注射低至1mg/kg的硫酸吗啡后20分钟内，瞳孔开始扩张。剂量相关的瞳孔散大在注射后35至50分钟达到最大，剂量为32mg/kg，持续3至4小时。瞳孔散大的特征是快速且明显的波动，这也与剂量相关，在32mg/kg硫酸吗啡时达到峰值。盐酸纳洛酮（1mg/kg）迅速逆转了瞳孔散大和波动，从而表明这是一种阿片受体介导的机制。除了为麻醉作用提供一种便捷的测量方法外，瞳孔可能为研究阿片受体机制提供一种特别有用的手段，因为在许多物种中，它是少数已知解剖途径和神经化学支配的情况之一。
