Asai T
Department of Anesthesiology, Kansai Medical University, Osaka, Japan.
Arzneimittelforschung. 1998 Aug;48(8):802-5.
The effects of morphine (CAS 57-27-2), nalbuphine (CAS 20594-83-6) and pentazocine (CAS 359-83-1) on gastric emptying of indigestible solids were studied. In rats, which were fasted for 24 h, either morphine, nalbuphine, pentazocine or saline was injected intraperitoneally, and ten steel balls (1.0 mm in diameter) were inserted into the stomach. At 3 h, the number of balls which had passed into the small intestine was counted. If these drugs inhibited gastric emptying, naloxone was injected concurrently to study the mechanisms of the inhibitory effect. Morphine, nalbuphine and pentazocine significantly inhibited gastric emptying (ED50:0.041 [95% confidence interval: 0.0078-0.14] mg kg-1, 0.0012 [0.00037-0.0081] mg kg-1 and 0.81 [0.41-1.30] mg kg-1, respectively). Naloxone 0.3 mg kg-1 antagonized the inhibitory effect of both morphine 1.3 mg kg-1 (ED75) and nalbuphine 0.005 mg kg-1 (ED75). In contrast, naloxone 0.3 or 1.0 mg kg-1 did not antagonize the effect of pentazocine 1.9 mg kg-1 (ED75), but a higher dose of naloxone (3.0 mg kg-1) did so. Therefore, in the rat, morphine, nalbuphine and pentazocine inhibit gastric emptying of indigestible solids, and it is likely that morphine and nalbuphine inhibit the emptying through the same opioid receptor, whereas pentazocine does so through a different receptor interaction.
研究了吗啡（化学物质登记号57 - 27 - 2）、纳布啡（化学物质登记号20594 - 83 - 6）和喷他佐辛（化学物质登记号359 - 83 - 1）对难消化固体胃排空的影响。在禁食24小时的大鼠中，腹腔注射吗啡、纳布啡、喷他佐辛或生理盐水，然后将10个直径1.0毫米的钢珠插入胃内。3小时后，计算进入小肠的钢珠数量。如果这些药物抑制胃排空，则同时注射纳洛酮以研究抑制作用的机制。吗啡、纳布啡和喷他佐辛均显著抑制胃排空（半数有效量：分别为0.041 [95%置信区间：0.0078 - 0.14]毫克/千克、0.0012 [0.00037 - 0.0081]毫克/千克和0.81 [0.41 - 1.30]毫克/千克）。0.3毫克/千克的纳洛酮拮抗了1.3毫克/千克吗啡（75%有效量）和0.005毫克/千克纳布啡（75%有效量）的抑制作用。相比之下，0.3或1.0毫克/千克的纳洛酮不能拮抗1.9毫克/千克喷他佐辛（75%有效量）的作用，但更高剂量的纳洛酮（3.0毫克/千克）可以。因此，在大鼠中，吗啡、纳布啡和喷他佐辛抑制难消化固体的胃排空，吗啡和纳布啡可能通过相同的阿片受体抑制排空，而喷他佐辛则通过不同的受体相互作用发挥作用。
