Asai T, Power I
Department of Anesthesiology, Kansai Medical University, Moriguchi City, Osaka, Japan.
Anesth Analg. 1999 Jan;88(1):204-8. doi: 10.1097/00000539-199901000-00038.
Naloxone is generally considered to be a pure antagonist, but it may produce several behavioral effects, such as hyperalgesia or stimulation of respiration. We studied the effect of naloxone on gastric emptying and gastrointestinal transit in rats. Six to eight Wistar rats (200-250 g) were used for each experiment. Either saline or naloxone (0.01-10 mg/kg) was injected intraperitoneally at 0 min. At 30 min, radiolabeled saline or milk 1 mL was infused into the stomach. At 60 min, gastric emptying and gastrointestinal transit were calculated by measuring the radioactivity in the gastrointestinal tract. Naloxone significantly inhibited gastric emptying of saline (P = 0.002) and of milk (P < 0.05), but not the gastrointestinal transit of either (P > 0.05). Gastric emptying of saline showed a significant peak (P < 0.05) in the dose-response curve at 0.7 mg/kg. Therefore, naloxone significantly inhibits gastric emptying of saline and milk, but not the gastrointestinal transit of either.
Although naloxone is generally considered to be a pure opioid receptor antagonist, it delays gastric emptying of saline or milk, as does morphine in the rat. However, it is uncertain from our results whether naloxone inhibited gastric emptying by antagonizing the effects of endogenous opioids.
纳洛酮通常被认为是一种纯粹的拮抗剂，但它可能会产生多种行为效应，如痛觉过敏或刺激呼吸。我们研究了纳洛酮对大鼠胃排空和胃肠转运的影响。每次实验使用6至8只Wistar大鼠（200 - 250克）。在0分钟时腹腔注射生理盐水或纳洛酮（0.01 - 10毫克/千克）。在30分钟时，将1毫升放射性标记的生理盐水或牛奶注入胃中。在60分钟时，通过测量胃肠道中的放射性来计算胃排空和胃肠转运。纳洛酮显著抑制生理盐水（P = 0.002）和牛奶（P < 0.05）的胃排空，但对两者的胃肠转运均无影响（P > 0.05）。生理盐水的胃排空在剂量 - 反应曲线中，0.7毫克/千克时出现显著峰值（P < 0.05）。因此，纳洛酮显著抑制生理盐水和牛奶的胃排空，但对两者的胃肠转运均无影响。
尽管纳洛酮通常被认为是一种纯粹的阿片受体拮抗剂，但它会延迟生理盐水或牛奶在大鼠体内的胃排空，吗啡在大鼠体内也有类似作用。然而，从我们的结果尚不确定纳洛酮是否通过拮抗内源性阿片类物质的作用来抑制胃排空。
