Kwon E D, Donovan J F, Schedl H P
Department of Urology, University of Iowa, College of Medicine, VA Medical Center, Iowa City 52242, USA.
J Surg Res. 1996 Feb 15;61(1):215-20. doi: 10.1006/jsre.1996.0107.
We systematically compared the individual effects of infusion rate, solution osmolality, and temperature on plasma solute secretion during luminal perfusion of an isolated 90-cm jejunal segment in the conscious and otherwise normal dog. The control state was perfusion at a rate of 3 ml/min of a 25 degrees C temperature solution containing (mM): NaCl, 40; NaHCO3, 10; and mannitol, 220 (320 mosm/kg). Increasing infusion rate from 3 to 9 ml/min increased secretion of Na-, K+, and urea (P < 0.05); further elevation of infusion rate to 18 ml/min increased only Cl- and urea secretion (P < 0.05). Thus, increasing infusion rate of the control solution had only a limited role in promoting solute secretion. In contrast, perfusion solutions elevated in osmolality to 600 and 1200 mosm/kg by mannitol progressively augmented the secretions of water, Na-, K+, Cl-, HCO3(-), Ca2+, and urea (P < 0.05). Perfusion of the 1200 mosm/kg solution produced solute secretions either equivalent to or greater than secretions obtained during 18-ml/min perfusion with the control solution, despite the fact that 1200 mosm/kg perfusion yielded about one-third the effluent volume. Warming of the control solution to progressively increase infusion temperatures from 29 to 41.9 degrees C increased (P < 0.05) water, Na+, K+, and Cl- secretion and HCO3 absorption linearly. Urea secretion increased (P < 0.05) above a temperature threshold of 38-38.9 degrees C. In conclusion, perfusion solution infusion rate, osmolality, and temperature are unique independent determinants of plasma solute secretion by jejunum. These data are the basis for optimizing the physical determinants of jejunal clearance for applying jejunal perfusion to treatment of renal failure.
我们系统地比较了输注速率、溶液渗透压和温度对清醒且健康的犬类离体90厘米空肠段腔内灌注期间血浆溶质分泌的个体影响。对照状态为以3毫升/分钟的速率灌注温度为25℃的溶液，该溶液含有（毫摩尔）：氯化钠40、碳酸氢钠10和甘露醇220（320毫渗摩尔/千克）。将输注速率从3毫升/分钟提高到9毫升/分钟会增加钠、钾和尿素的分泌（P<0.05）；将输注速率进一步提高到18毫升/分钟仅增加氯和尿素的分泌（P<0.05）。因此，增加对照溶液的输注速率在促进溶质分泌方面作用有限。相比之下，通过甘露醇将渗透压提高到600和1200毫渗摩尔/千克的灌注溶液会逐渐增加水、钠、钾、氯、碳酸氢根、钙和尿素的分泌（P<0.05）。尽管1200毫渗摩尔/千克灌注产生的流出液体积约为对照溶液18毫升/分钟灌注时的三分之一，但灌注1200毫渗摩尔/千克溶液产生的溶质分泌量与对照溶液18毫升/分钟灌注时相当或更大。将对照溶液加热以将输注温度从29℃逐渐提高到41.9℃会使水、钠、钾和氯的分泌以及碳酸氢根的吸收呈线性增加（P<0.05）。尿素分泌在温度阈值38 - 38.9℃以上增加（P<0.05）。总之，灌注溶液的输注速率、渗透压和温度是空肠血浆溶质分泌独特的独立决定因素。这些数据是优化空肠清除的物理决定因素以将空肠灌注应用于肾衰竭治疗的基础。
