Bill A, Andersson S E, Almegård B
Department of Physiology and Medical Biophysics, University of Uppsala, Sweden.
Acta Physiol Scand. 1990 Apr;138(4):479-85. doi: 10.1111/j.1748-1716.1990.tb08875.x.
The effects of intracameral injections of cholecystokinin (CCK) on the pupil size were determined in monkeys, cats, rabbits, rats and guinea-pigs. In animals under muscarinic cholinergic blockade, CCK caused miosis in monkeys but not in the other species investigated. In monkeys CCK-8 was more potent than CCK-33, which was, however, much more potent than non-sulphated CCK-8. These observations indicate that peripheral type A receptors mediated the miotic response. The effect of CCK-8 was not appreciably influenced by pretreatment with indomethacin, 3 mg kg-1 body wt, indicating that prostaglandins were not involved in the response. Nerve blockade with 0.9 micrograms tetrodotoxin intracamerally had no clear effect on the dose-response relationship for CCK-8. The effect of the peptide thus seems to be directly on receptors on the pupillary sphincter muscle. Pretreatment with lorglumide caused a dose-dependent rightward shift of the dose-response curve, indicating competitive antagonism. The results indicate that in monkeys, but not in rabbit, cats, rats and guinea-pigs, CCK is a potent miotic with a direct effect on the pupillary sphincter mediated by type A CCK receptors on the muscle.
在猴子、猫、兔、大鼠和豚鼠中测定了前房内注射胆囊收缩素（CCK）对瞳孔大小的影响。在毒蕈碱型胆碱能阻断的动物中，CCK在猴子中引起瞳孔缩小，但在所研究的其他物种中未引起瞳孔缩小。在猴子中，CCK-8比CCK-33更有效，然而，CCK-33比非硫酸化的CCK-8有效得多。这些观察结果表明，外周A型受体介导了瞳孔缩小反应。用3mg/kg体重的吲哚美辛预处理对CCK-8的作用没有明显影响，表明前列腺素不参与该反应。前房内注射0.9μg河豚毒素进行神经阻断对CCK-8的剂量反应关系没有明显影响。因此，该肽的作用似乎直接作用于瞳孔括约肌上的受体。用洛谷胺预处理导致剂量反应曲线呈剂量依赖性右移，表明存在竞争性拮抗作用。结果表明，在猴子中，而不是在兔、猫、大鼠和豚鼠中，CCK是一种有效的缩瞳剂，对由肌肉上的A型CCK受体介导的瞳孔括约肌有直接作用。
