Effects of meal size on postprandial responses in juvenile Burmese pythons (Python molurus).
Effects of meal size on postprandial responses in juvenile Burmese pythons (Python molurus).
复制标题
DOI：
10.1152/ajpregu.1997.272.3.r902
复制
发表时间：
1997-03
期刊：
影响因子：
--
通讯作者：
S. Secor;J. Diamond
中科院分区：
文献类型：
--
作者：
S. Secor;J. Diamond
此前有报道称，蟒蛇在进食相当于蛇身体质量25%的食物时，肠道质量和转运体活动会发生很大变化。这篇论文研究了这些和其他对进食的适应性反应如何随食物的大小(占体重的5%、25%或65%)而变化。大餐需要更长的时间才能通过胃和小肠。在进食一顿饭后，氧气消耗率上升到禁食水平的32倍，并在长达13天的时间里保持显著高水平。这一特定的动态行为相当于摄入能量的29%-36%。在25%和65%的大餐后，血浆氯离子显著下降，而血浆二氧化碳、葡萄糖、肌酐和尿素氮增加了2.3-4.2倍。在1天内，肠粘膜肿块增加一倍以上，肠浆膜、肝、胃、胰腺和肾脏的肿块也增加。肠道对氨基酸和D-葡萄糖的摄取率增加了43倍，而摄取能力增加了59倍。其中许多反应(耗氧率、肾脏肥大、D-葡萄糖和L赖氨酸摄取)的大小随着所研究的最大食量的进食而增加；其他反应(钠非依赖性L亮氨酸摄取、血浆氯离子摄取和器官质量)在相当于蛇体重的25%的食物中稳定；还有其他反应(第一天的营养摄取、被动葡萄糖摄取、血浆蛋白质和碱性磷酸酶)要么全有要么没有，与食物大小无关，在占体重的5%到65%之间。蟒蛇会经历一系列的餐后反应，其中许多对食物大小的敏感度不同。
Pythons were reported previously to exhibit large changes in intestinal mass and transporter activities on consuming meals equal to 25% of the snake's body mass. This paper examines how those and other adaptive responses to feeding vary with meal size (5, 25, or 65% of body mass). Larger meals took longer to pass through the stomach and small intestine. After ingestion of a meal, O2 consumption rates rose to up to 32 times fasting levels and remained significantly elevated for up to 13 days. This specific dynamic action equaled 29-36% of ingested energy. After 25 and 65% size meals, plasma Cl- significantly dropped, whereas plasma CO2, glucose, creatinine, and urea nitrogen increased as much as a factor of 2.3-4.2. Within 1 day the intestinal mucosal mass more than doubled, and masses of the intestinal serosa, liver, stomach, pancreas, and kidneys also increased. Intestinal uptake rates of amino acids and of D-glucose increased by up to 43 times fasting levels, whereas uptake capacities increased by up to 59 times fasting levels. Magnitudes of many of these responses (O2 consumption rate, kidney hypertrophy, and D-glucose and L-lysine uptake) increased with meal size up to the largest meals studied; other responses (Na+-independent L-leucine uptake, plasma Cl-, and organ masses) plateaued at meals equal to 25% of the snake's body mass; and still other responses (nutrient uptake at day 1, passive glucose uptake, and plasma protein and alkaline phosphatase) were all-or-nothing, being independent of meal size between 5 and 65% of body mass. Pythons undergo a wide array of postprandial responses, many of which differ in their sensitivity to meal size.