Phifer C B, Sikes C R, Hall W G
Am J Physiol. 1986 May;250(5 Pt 2):R807-14. doi: 10.1152/ajpregu.1986.250.5.R807.
Six-day-old rat pups, tested away from the dam, vigorously ingested orally infused milk for up to 90 min when the ingested milk was allowed to drain through a gastric fistula. Total intake in pups with unplugged fistulas was more than double that consumed by littermates with plugged fistulas. This persistent feeding could not be due to the absence of postgastric cues because blocking movement of the milk into the intestine with a closed pyloric noose resulted in less intake than when the noose was open. Furthermore, a 5% body weight gastric preload of milk or nonnutritive saline suppressed intake in pups with either open or closed pyloric nooses by an amount equal to the preload. Regardless of noose or preload condition, ingestion stopped when stomach content reached approximately 6.5% of body weight. Thus level of gastric fill appeared critical for intake control. When gastric fistulas were unplugged after pups had ingested milk until they stopped, vigorous ingestion followed, with total intakes of up to 20% body weight. Intake termination in young rat pups thus appears to be controlled exclusively by gastric fill level; pregastric signals alone appear insufficient, and postgastric signals appear unnecessary for termination of intake.
出生6天的幼鼠在与母鼠分开的情况下接受测试，当经胃瘘管引流摄入的乳汁时，它们会积极地经口摄入乳汁长达90分钟。未堵塞瘘管的幼鼠的总摄入量比堵塞瘘管的同窝幼鼠的摄入量多一倍以上。这种持续的进食不可能是由于缺乏胃后线索，因为用封闭的幽门套索阻止乳汁进入肠道时的摄入量比套索开放时少。此外，5%体重的胃内乳汁预负荷或无营养盐水预负荷会使幽门套索开放或封闭的幼鼠的摄入量减少，减少量与预负荷量相等。无论套索或预负荷情况如何，当胃内容物达到体重的约6.5%时，摄食停止。因此，胃充盈程度似乎对摄入量控制至关重要。当幼鼠摄入乳汁直至停止后再拔掉胃瘘管时，会再次出现积极的摄食行为，总摄入量可达体重的20%。因此，幼鼠的摄食终止似乎完全由胃充盈程度控制；仅胃前信号似乎不足以控制摄食终止，胃后信号对于摄食终止似乎也不必要。
