Serra J, Azpiroz F, Malagelada J R
Digestive System Research Unit, Hospital General Vall d'Hebron, Autonomous University of Barcelona, Spain.
Gastroenterology. 1995 Dec;109(6):1742-9. doi: 10.1016/0016-5085(95)90739-4.
BACKGROUND & AIMS: Intestinal reflexes induced by distention in dogs are facilitated by either simultaneous or previous distentions. The aim of this study was to determine whether these phenomena also modulate the responses to intestinal distention, particularly perception, in humans.
Perception and intestinal relaxation were measured in 11 healthy subjects in response to increasing jejunal balloon distentions tested (by stimulus-response trials) alone, as control, and with conditioning distentions applied either simultaneously, immediately (10 seconds) before at the same site, or immediately before and 5 cm distant. In 8 additional subjects, the effect of prolonged (90-minute) conditioning distention was tested.
Conditioning had more pronounced effects on perception than on intestinal reflexes. Perception of intestinal distention increased (by 84 +/- 47%; P < 0.05) when a simultaneous distention was applied nearby. By contrast, perception decreased (by 38 +/- 12%; P < 0.05) when a previous distention was applied at the same but not at an adjacent site. Prolonged intestinal distention elicited remarkably stable perception during a 90-minute period. The effects of conditioning were unrelated to intestinal compliance because it remained unchanged.
In humans, temporospatial interactions of gut stimuli activate modulatory phenomena that determine the perception intensity of the stimuli.
在狗身上，由扩张引起的肠道反射会因同时或先前的扩张而得到促进。本研究的目的是确定这些现象是否也会调节人类对肠道扩张的反应，特别是感觉。
对11名健康受试者进行检测，测量其对逐渐增加的空肠气囊扩张的感觉和肠道舒张情况，检测方式包括单独进行（作为对照）以及同时施加、在同一部位提前10秒或提前并在距离5厘米处施加条件性扩张。另外对8名受试者测试了持续90分钟的条件性扩张的效果。
条件作用对感觉的影响比对肠道反射的影响更显著。当在附近同时施加扩张时，对肠道扩张的感觉增强（增加84±47%；P<0.05）。相比之下，当在同一部位而非相邻部位提前施加扩张时，感觉下降（下降38±12%；P<0.05）。在90分钟内，持续的肠道扩张引发了非常稳定的感觉。条件作用的效果与肠道顺应性无关，因为肠道顺应性保持不变。
在人类中，肠道刺激的时空相互作用激活了调节现象，这些现象决定了刺激的感觉强度。
