Pickworth W B, Sharpe L G
J Pharmacol Exp Ther. 1985 Sep;234(3):603-6.
Morphine has species-characteristic effects on pupillary size The effects of morphine on pupillary size, fluctuations and the light reflex were tested with an infrared video pupillometer in the gallamine-paralyzed cat. Compared with saline or base-line responses, i.v. morphine (0.06-1.5 mg/kg) caused a dose-related decrease in the light reflex and fluctuations but increased pupil size. Naloxone (1-100 micrograms/kg i.v.), injected 1 h after morphine, reversed all pupillary effects. Levorphanol (0.5 mg/kg i.v.) had pupillary actions like those of morphine, but dextrophan (0.5 mg/kg i.v.) was inactive. Sympathectomy did not alter the morphine response. It was concluded that morphine disrupts parasympathetic innervation of the iris through interactions with opiate receptors, some of which are in the brain. The morphine-induced changes on the light reflex and fluctuations in the cat are opposite those reported in the rat and rabbit. These results enlarge on the familiar species-dependent effects of opiates on pupillary size.
吗啡对瞳孔大小有物种特异性效应
在加拉明麻痹的猫身上，用红外视频瞳孔计测试了吗啡对瞳孔大小、波动及光反射的影响。与生理盐水或基线反应相比，静脉注射吗啡（0.06 - 1.5毫克/千克）导致光反射和波动呈剂量相关的降低，但瞳孔大小增加。吗啡注射1小时后静脉注射纳洛酮（1 - 100微克/千克）可逆转所有瞳孔效应。左啡诺（0.5毫克/千克静脉注射）具有与吗啡相似的瞳孔作用，但右啡烷（0.5毫克/千克静脉注射）无活性。交感神经切除术未改变吗啡反应。得出的结论是，吗啡通过与阿片受体相互作用破坏虹膜的副交感神经支配，其中一些受体在大脑中。吗啡对猫的光反射和波动的诱导变化与在大鼠和兔子中报道的相反。这些结果进一步说明了阿片类药物对瞳孔大小的常见物种依赖性效应。
