Kohn R A, Schwab C G, Bozak C K, Hylton W E
Department of Animal and Nutritional Sciences, University of New Hampshire, Durham 03824.
J Anim Sci. 1993 Jun;71(6):1641-7. doi: 10.2527/1993.7161641x.
Total blood flow from an intestinal segment (TBF) was altered to determine effects on blood flow at the absorptive site (ASBF) and lysine absorption. Venous blood flow was restricted using a peristaltic pump to 20, 35, 50, 65, and 80% of the initial unrestricted rate. Lysine absorption and ASBF were determined from recovery of 14C and 3H in blood from intestinally perfused [14C]L-lysine and 3H2O, respectively. Fluid flux in the intestinal lumen was estimated from the difference in polyethylene glycol concentrations in luminal infusate and effluent. Restriction of TBF proportionally reduced ASBF, which composed 3 to 6% of TBF. Lysine absorption was reduced linearly during reduction of TBF. Fluid absorption varied among calves but was independent of TBF. Differences between loss of radioactive marker from perfusate and recovery in blood suggested a loss of 3H2O from the intestinal segment that was independent of TBF. Changes in blood flow to the small intestine may affect nutrient absorption in ruminants.
改变肠段的总血流量（TBF），以确定其对吸收部位血流量（ASBF）和赖氨酸吸收的影响。使用蠕动泵将静脉血流量限制在初始非限制速率的20%、35%、50%、65%和80%。分别通过肠道灌注的[¹⁴C]L-赖氨酸和³H₂O在血液中¹⁴C和³H的回收率来测定赖氨酸吸收和ASBF。根据肠腔灌注液和流出液中聚乙二醇浓度的差异来估计肠腔内的液体通量。TBF的限制成比例地降低了ASBF，ASBF占TBF的3%至6%。在TBF降低期间，赖氨酸吸收呈线性降低。不同犊牛之间的液体吸收情况有所不同，但与TBF无关。灌注液中放射性标记物的损失与血液中回收率之间的差异表明，肠段存在³H₂O的损失，且该损失与TBF无关。小肠血流量的变化可能会影响反刍动物的营养吸收。
