Haigler H J, Mittleman R S
Department of Pharmacology, Emory University School of Medicine, Atlanta, GA 30322.
Brain Res Bull. 1978 Nov-Dec;3(6):655-62. doi: 10.1016/0361-9230(78)90013-8.
Morphine administered intracerebrally (IC) (10 micrograms as the base on each side) into the MRF produced a significant dose dependent elevation of nociceptive threshold (i.e., analgesia) on the tail flick test and hemostat pinch test. However, morphine IC at lower doses had no analgesic effect. After morphine was injected IC (10 micrograms, bilaterally) into the MRF, naloxone, a specific narcotic antagonist, administered either IC at the same site (15 micrograms, bilaterally) or subcutaneously (10 mg/kg), antagonized the antinociceptive effects of morphine. Thirty percent of the animals given bilateral microinjection of 10 micrograms of morphine displayed hyperreactivity to mild stimuli. This hyperreactivity was not attenuated by large IC or systemic doses of naloxone. It was concluded that the MRF is a site where morphine may act to produce analgesia by a specific narcotic mechanism of action.
将吗啡（以碱基计，每侧10微克）脑室内注射到中脑网状结构（MRF），在甩尾试验和止血钳夹试验中可产生显著的剂量依赖性伤害性阈值升高（即镇痛作用）。然而，较低剂量的吗啡脑室内注射没有镇痛效果。在将吗啡（双侧各10微克）脑室内注射到MRF后，特异性阿片拮抗剂纳洛酮，在同一部位脑室内注射（双侧各15微克）或皮下注射（10毫克/千克），可拮抗吗啡的抗伤害感受作用。双侧微量注射10微克吗啡的动物中，30%对轻度刺激表现出反应过度。这种反应过度不会被大剂量脑室内注射或全身给药的纳洛酮减弱。得出的结论是，中脑网状结构是吗啡可能通过特定阿片作用机制发挥镇痛作用的部位。
