Division of Basic Medical Sciences, St. George's University of London, Cranmer Terrace, SW17 0RE, London, United Kingdom.
World J Gastroenterol. 2009 Dec 28;15(48):6034-43. doi: 10.3748/wjg.15.6034.
To characterize the gastric myoelectric activity (GMA) and intra-abdominal pressure changes induced by emetic stimuli (apomorphine and cisplatin) in the ferret.
GMA and intra-abdominal pressure were recorded in conscious, unrestrained ferrets surgically implanted with radiotelemetry transmitters. Animals were challenged with apomorphine (0.25 mg/kg sc) and cisplatin (10 mg/kg ip), and the emetic response was quantified via direct observation and intra-abdominal pressure recording for 1 h and 4 h, respectively. The GMA was analyzed by spectral analysis; the parameters used to characterize the GMA were the dominant frequency (DF) and the repartition of spectral power in the bradygastric, normogastric and tachygastric frequency ranges.
Retches were identified on the intra-abdominal pressure trace as peaks 0.30 +/- 1.01 s in duration and 59.57 +/- 2.74 mmHg in amplitude, vomit peaks were longer (0.82 +/- 0.06 s, P < 0.01) and reached a higher pressure (87.73 +/- 8.12 mmHg, P < 0.001). The number of retches and vomits quantified via direct observation [apomorphine: 65.5 +/- 11.8 retches + vomits (R+V), cisplatin: 202.6 +/- 64.1 R+V] and intra-abdominal pressure (apomorphine: 68.3 +/- 13.7 R+V, n = 8; cisplatin: 219.0 +/- 69.2 R+V, n = 8) were correlated (r = 0.97, P < 0.0001) and the timing of emesis was consistent between the 2 methods. Apomorphine induced a decrease in normogastria from 45.48% +/- 4.35% to 36.70 +/- 4.34% (n = 8, P < 0.05) but the DF of the slow waves was not changed [8.95 +/- 0.25 counts/min (cpm) vs 8.68 +/- 0.35 cpm, n = 8, P > 0.05]. Cisplatin induced a decrease in normogastria from 55.83% +/- 4.30% to 29.22% +/- 5.16% and an increase in bradygastria from 14.28% +/- 2.32% to 31.19% +/- 8.33% (n = 8, P < 0.001) but the DF (9.14 +/- 0.13 cpm) remained unchanged (P > 0.05). The GMA changes induced by cisplatin preceded the emetic response as normogastria was reduced for 1 h before the onset of emesis (57.61% +/- 5.66% to 39.91% +/- 5.74%, n = 6, P < 0.05). Peri-emesis analysis revealed that the GMA was significantly disturbed during and immediately after, but not immediately before, the emetic episodes.
The induction of emesis is reliably associated with a disrupted GMA, but changes may also occur prior to and following the emetic response.
描述呕吐刺激（阿朴吗啡和顺铂）引起的胃电活动（GMA）和腹内压变化在雪貂中的特征。
在接受过放射性遥测发射器手术植入的清醒、不受约束的雪貂中记录 GMA 和腹内压。用阿朴吗啡（0.25 mg/kg sc）和顺铂（10 mg/kg ip）对动物进行挑战，并通过直接观察和腹内压记录分别在 1 小时和 4 小时内量化呕吐反应。通过频谱分析分析 GMA；用于描述 GMA 的参数是主导频率（DF）和在胃缓、胃正常和胃快频率范围内的频谱功率分布。
在腹内压迹线上，呕逆被识别为持续 0.30 +/- 1.01 秒、幅度为 59.57 +/- 2.74 mmHg 的峰值，呕吐峰值持续时间更长（0.82 +/- 0.06 s，P < 0.01），达到更高的压力（87.73 +/- 8.12 mmHg，P < 0.001）。通过直接观察（阿朴吗啡：65.5 +/- 11.8 呕逆+呕吐（R+V），顺铂：202.6 +/- 64.1 R+V）和腹内压（阿朴吗啡：68.3 +/- 13.7 R+V，n = 8；顺铂：219.0 +/- 69.2 R+V，n = 8）量化的呕逆和呕吐数量相关（r = 0.97，P < 0.0001），并且两种方法的呕吐时间一致。阿朴吗啡诱导胃正常频率从 45.48% +/- 4.35%下降到 36.70 +/- 4.34%（n = 8，P < 0.05），但慢波的 DF 没有改变[8.95 +/- 0.25 计数/分钟（cpm）与 8.68 +/- 0.35 cpm，n = 8，P > 0.05]。顺铂诱导胃正常频率从 55.83% +/- 4.30%下降到 29.22% +/- 5.16%，胃缓频率从 14.28% +/- 2.32%增加到 31.19% +/- 8.33%（n = 8，P < 0.001），但 DF（9.14 +/- 0.13 cpm）保持不变（P > 0.05）。顺铂引起的 GMA 变化先于呕吐反应，因为在呕吐发作前 1 小时胃正常已经减少（57.61% +/- 5.66%至 39.91% +/- 5.74%，n = 6，P < 0.05）。呕吐发作期间和之后的分析显示，GMA 在呕吐发作期间和之后受到显著干扰，但在呕吐发作之前没有受到干扰。
呕吐的诱导与 GMA 的破坏可靠相关，但变化也可能发生在呕吐反应之前和之后。
