Slater P, Starkie D A
Naunyn Schmiedebergs Arch Pharmacol. 1987 Jan;335(1):54-8. doi: 10.1007/BF00165036.
A mechanical apparatus was used to measure the resistance of the hindlegs to flexion in conscious rats. Systemically-administered morphine (7.5-12.5 mg/kg) caused increased muscle tone in the limbs. In rats with intracerebral cannulae, intrastriatal morphine (5-15 micrograms) had no effect on limb tone, whereas in increase in limb tone was induced by morphine (1-30 micrograms) in the globus pallidus. A strong and sustained increase in limb tone developed when morphine (0.2-2.5 micrograms) and the mu opiate receptor agonist DAGO (1.5-2.5 micrograms) were administered into the periaqueductal gray region of the midbrain, whereas the delta opiate receptor agonist DADLE (2.5-8 micrograms) was ineffective. The increased limb tone induced by opiates may be generated by mu-type receptors in at least two areas of brain.
使用一种机械装置来测量清醒大鼠后肢的屈曲阻力。全身给予吗啡（7.5 - 12.5毫克/千克）会导致肢体肌肉张力增加。在脑内插管的大鼠中，纹状体内注射吗啡（5 - 15微克）对肢体张力没有影响，而苍白球内注射吗啡（1 - 30微克）会引起肢体张力增加。当中脑导水管周围灰质区域注射吗啡（0.2 - 2.5微克）和μ阿片受体激动剂DAGO（1.5 - 2.5微克）时，会出现强烈且持续的肢体张力增加，而δ阿片受体激动剂DADLE（2.5 - 8微克）则无效。阿片类药物诱导的肢体张力增加可能至少由脑内两个区域的μ型受体产生。
