Gisolfi C V, Summers R W, Schedl H P, Bleiler T L
Department of Exercise Science, University of Iowa College of Liberal Arts, Iowa City.
J Appl Physiol (1985). 1992 Nov;73(5):2142-50. doi: 10.1152/jappl.1992.73.5.2142.
Eight men positioned a triple-lumen tube in the duodenojejunum. By use of segmental perfusion, 2, 4, 6, or 8% solutions of glucose (111-444 mM), sucrose (55-233 mM), a maltodextrin [17-67 mM, avg. chain length = 7 glucose units (7G)], or a corn syrup solid [40-160 mM, avg. chain length = 3 glucose units (3G)] were perfused at 15 ml/min for 70 min after a 30-min equilibration period. All solutions were made isotonic with NaCl, except 6 and 8% glucose solutions, which were hypertonic. An isotonic NaCl solution was perfused as control. Water absorption (range: 9-15 ml.h-1.cm-1) did not differ for the 2, 4, and 6% CHO solutions but was greater (P < 0.05) than absorption from control (3.0 +/- 2.2 ml.h-1.cm-1). The 8% glucose and 3G solutions reduced (P < 0.05) net water flux compared with their 2, 4, and 6% solutions, but 8% sucrose and 8% 7G solutions promoted water absorption equivalent to lower CHO concentrations. Water absorption was independent of [Na+] in the original solution. In the test segment, 1) Na+ flux correlated with net water flux (r = 0.72, P < 0.01), K+ (r = 0.78, P < 0.01), and [Na+] (r = 0.68, P < 0.001); 2) Na+ absorption occurred at luminal [Na+] as low as 50 mM; 3) glucose transport increased linearly over the luminal concentration range of 40-180 mM; and 4) net water flux was similar over a range of glucose-to-Na+ concentration ratios of 0.4:1 to 3.5:1.(ABSTRACT TRUNCATED AT 250 WORDS)
八名男性将一根三腔管放置在十二指肠空肠处。通过分段灌注，在30分钟的平衡期后，以15毫升/分钟的速度灌注2%、4%、6%或8%的葡萄糖（111 - 444毫摩尔）、蔗糖（55 - 233毫摩尔）、一种麦芽糊精[17 - 67毫摩尔，平均链长 = 7个葡萄糖单位（7G）]或一种玉米糖浆固体[40 - 160毫摩尔，平均链长 = 3个葡萄糖单位（3G）]溶液70分钟。除了6%和8%的葡萄糖溶液为高渗溶液外，所有溶液均用氯化钠制成等渗溶液。灌注等渗氯化钠溶液作为对照。2%、4%和6%的碳水化合物溶液的水吸收量（范围：9 - 15毫升·小时⁻¹·厘米⁻¹）没有差异，但高于对照（3.0 ± 2.2毫升·小时⁻¹·厘米⁻¹）的吸收量（P < 0.05）。与2%、4%和6%的溶液相比，8%的葡萄糖和3G溶液降低了（P < 0.05）净水通量，但8%的蔗糖和8%的7G溶液促进的水吸收量与较低碳水化合物浓度时相当。水吸收与原始溶液中的[Na⁺]无关。在测试段，1）Na⁺通量与净水通量相关（r = 0.72，P < 0.01）、与K⁺相关（r = 0.78，P < 0.01）以及与[Na⁺]相关（r = 0.68，P < 0.001）；2）在管腔内[Na⁺]低至50毫摩尔时发生Na⁺吸收；3）葡萄糖转运在40 - 180毫摩尔的管腔浓度范围内呈线性增加；4）在0.4:1至3.5:1的一系列葡萄糖与Na⁺浓度比范围内，净水通量相似。（摘要截断于250字）
