Vinagre A M, Collares E F
Núcleo de Medicina e Cirurgia Experimental, Faculdade de Ciências Médicas, Universidade Estadual de Campinas, Campinas, SP, Brasil.
Braz J Med Biol Res. 2007 Jul;40(7):903-9. doi: 10.1590/s0100-879x2006005000119.
Dipyrone (Dp) delays gastric emptying (GE) in rats. There is no information about whether 4-aminoantipyrine (AA), one of its metabolites, has the same effect. The objectives of the present study were to assess the effects of AA and Dp on GE when administered intravenously (iv) and intracerebroventricularly (icv) (240 micromol/kg and 4 micromol/animal, respectively) and on gastric compliance when administered iv (240 micromol/kg). GE was determined in male Wistar rats weighing 250-300 g (5-10 per group) after icv or iv injection of the drug by measuring percent gastric retention (GR) of a saline meal labeled with phenol red 10 min after administration by gavage. Gastric compliance was estimated in anesthetized rats (10-11 per group), with the construction of volume-pressure curves during intragastric infusion of a saline meal. Compliance was significantly greater in animals receiving Dp (mean +/- SEM = 0.26 +/- 0.009 mL/mmHg) and AA (0.24 +/- 0.012 mL/mmHg) than in controls (0.19 +/- 0.009 mL/mmHg). AA and Dp administered iv significantly increased GR (64.4 +/- 2.5 and 54.3 +/- 3.8%, respectively) compared to control (34 +/- 2.2%), a phenomenon observed only with Dp after icv administration. Subdiaphragmatic vagotomy reduced the effect of AA (GR = 31.4 +/- 1.5%) compared to sham-treated animals. Baclofen, a GABAB receptor agonist, administered icv significantly reduced the effect of AA (GR = 28.1 +/- 1.3%). We conclude that Dp and AA increased gastric compliance and AA delayed GE, with the participation of the vagus nerve, through a pathway that does not involve a direct action of the drug on the central nervous system.
安乃近（Dp）可延缓大鼠胃排空（GE）。关于其代谢产物之一4-氨基安替比林（AA）是否有相同作用尚无相关信息。本研究的目的是评估静脉注射（iv）和脑室内注射（icv）（分别为240微摩尔/千克和4微摩尔/只动物）时AA和Dp对胃排空的影响，以及静脉注射（240微摩尔/千克）时对胃顺应性的影响。通过测量灌胃给予药物10分钟后用酚红标记的生理盐水餐的胃潴留百分比（GR），在体重250 - 300克的雄性Wistar大鼠（每组5 - 10只）中，icv或iv注射药物后测定胃排空。在麻醉大鼠（每组10 - 11只）中，通过在胃内输注生理盐水餐期间构建容积 - 压力曲线来估计胃顺应性。接受Dp（均值±标准误 = 0.26±0.009毫升/毫米汞柱）和AA（0.24±0.012毫升/毫米汞柱）的动物的顺应性显著高于对照组（0.19±0.009毫升/毫米汞柱）。与对照组（34±2.2%）相比，静脉注射AA和Dp显著增加了GR（分别为64.4±2.5%和54.3±3.8%），这种现象仅在icv注射Dp后观察到。与假手术动物相比，膈下迷走神经切断术降低了AA的作用（GR = 31.4±1.5%）。脑室内注射GABAB受体激动剂巴氯芬显著降低了AA的作用（GR = 28.1±1.3%）。我们得出结论，Dp和AA增加了胃顺应性，AA通过不涉及药物对中枢神经系统直接作用的途径，在迷走神经参与下延缓了胃排空。
