RATE OF FLOW OF DIGESTA AND ELECTRICAL-ACTIVITY OF SMALL-INTESTINE IN DOGS AND SHEEP
RATE OF FLOW OF DIGESTA AND ELECTRICAL-ACTIVITY OF SMALL-INTESTINE IN DOGS AND SHEEP
复制标题
DOI：
10.1113/jphysiol.1975.sp011003
复制
发表时间：
1975-01-01
影响因子：
5.5
通讯作者：
RUCKEBUSCH, Y
中科院分区：
文献类型：
--
作者：
BUENO, L;FIORAMONTI, J;RUCKEBUSCH, Y
1.通过长期植入空肠上的电极连续记录有意识的狗和羊的小肠尖峰活动，并以20秒的间隔进行求和。该活性与肠内容物的通过时间和流速相关，分别通过酚红和连续标记物输注的稀释来估计。另外，在一些绵羊中，食糜流量是直接从空肠近端部分的插管测量的，也可以使用电磁流量计来测量。 2. 在禁食的狗和正常饮食的羊中，肠道活动的特征是迁移的肌电复合体，包括不规则阶段和随后的规则阶段。这些迁移的肌电复合体在一段时间不活动后定期发生，频率为 15-20/24 小时。喂食后的狗会出现持续的峰值活动并持续 7-8 小时。这与比禁食期间观察到的更高的流速和更短的传输时间有关。在绵羊中，通过静脉注射 5-羟色氨酸可以诱导连续的尖峰活动，同样，这也伴随着比对照期间记录的更快的流速和更短的传输时间。 3. 在这两个物种中，当在电不活动期间注射酚红丸时，出现最长的通过时间。当在常规加药活动之前进行推注时，观察到相对较短的传输时间。 4.当通过腹腔注射高渗盐水诱导肠松弛时，没有尖峰活动，并且输注溶液的通过时间大大延长，特别是在绵羊中。狗体内持续存在明显的消化内容物流动。 5. 绵羊肠道内容物在 10-15 分钟内间歇性流动，其频率与迁移的肌电复合体相同。三分之二的流量发生在不规则峰值活动之前的 4-6 分钟内。 6. 结论是，在禁食的狗和绵羊中，迁移的肌电复合体控制着肠内容物流动所依赖的压力梯度。这主要是通过不规则的尖峰活动的延长阶段来完成的，并且建议随后的规则的尖峰活动虽然本身不具有推进性，但可以作为防止消化物回流到肠道的静止部分的屏障。当通过给狗喂食和给羊注射 5-羟色氨酸诱导连续的尖峰活动时，肠道的任何部分都不会静止，并且持续不规则的尖峰活动会缩短通过时间。
1. Spiking activity of the small intestine in the conscious dog and sheep was recorded continuously from electrodes chronically implanted on the jejunum and summed at intervals of 20 sec. The activity was related to the transit time and flow rate of intestinal contents as estimated by phenol red and by dilution of continuous marker infusions respectively. Also in some sheep the flow of digesta was measured directly from a cannula in the proximal part of the jejunum, and also by use of an electromagnetic flow meter. 2. In the fasted dog and in sheep on a normal diet the intestinal activity was characterized by a migrating myo‐electric complex comprising an irregular phase followed by a regular phase. These migrating myo‐electric complexes occurred regularly after a period of inactivity at a frequency of 15–20/24 hr. In dogs after feeding, a continuous spiking activity appeared and persisted for periods of 7–8 hr. This was associated with much higher rates of flow and shorter transit times than were observed during fasting. In sheep, continuous spiking activity could be induced by intravenous injection of 5‐hydroxytryptophan and this, similarly, was accompanied by a more rapid flow and a shorter transit time than recorded during the control period. 3. In both species the longest transit time occurred when a phenol red bolus was injected during the period of electrical inactivity. Relatively short transit times were observed when the bolus was administered just before the period of regular spiking activity. 4. When relaxation of the bowel was induced by intraperitoneal injection of hypertonic saline there was no spiking activity and the transit time for the infused solution was greatly lengthened, especially in the sheep. A noticeable flow of digestive contents persisted in the dog. 5. In the sheep the intestinal contents flowed intermittently during periods of 10–15 min and at the same frequency as the migrating myo‐electric complex. Two thirds of this flow took place in the 4–6 min immediately preceding the periods of irregular spiking activity. 6. It is concluded that in the fasted dog and in the sheep the migrating myo‐electric complex controls the pressure gradients on which the flow of intestinal contents depends. This is accomplished in the main by the prolonged phase of irregular spiking activity, and it is suggested that the regular spiking activity which follows it, though not in itself propulsive, serves as a barrier to prevent backflow of digesta into the quiescent part of the intestine. When continuous spiking activity is induced, by feeding in the dog and by injection of 5‐hydroxytryptophan in the sheep, no part of the intestine is quiescent and the transit time is shortened by the incessant irregular spiking activity.