GLUTAMINE STIMULATES PROSTAGLANDIN-SENSITIVE NA+-H+ EXCHANGE IN EXPERIMENTAL PORCINE CRYPTOSPORIDIOSIS
GLUTAMINE STIMULATES PROSTAGLANDIN-SENSITIVE NA+-H+ EXCHANGE IN EXPERIMENTAL PORCINE CRYPTOSPORIDIOSIS
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DOI：
10.1016/0016-5085(94)90393-x
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发表时间：
1994-06-01
期刊：
影响因子：
29.4
通讯作者：
GOMEZ, G
中科院分区：
文献类型：
--
作者：
ARGENZIO, RA;RHOADS, JM;GOMEZ, G
背景/目的：最近对仔猪隐孢子虫病的研究表明，损伤导致钠-葡萄糖共转运受损，前列腺素介导中性盐吸收抑制。由于谷氨酰胺能刺激中性和电生Na+吸收，本研究探讨了前列腺素抑制Na+吸收的机制以及谷氨酰胺对这一过程的影响。方法：将对照和感染猪的回肠粘膜置于Ussing小室中进行流量研究，或与[14C]谷氨酰胺或[14C]-葡萄糖孵育以进行代谢研究。结果：葡萄糖和谷氨酰胺诱导的Na+吸收和对照回肠短路电流的当量增加，2~2.5μEq·cm−2·h−1。尽管绒毛表面积减少到对照组的1/3，但谷氨酰胺使感染回肠中性和生电的Na+吸收增加了3.5±0.5μEq·cm−2·h−1，而葡萄糖的作用仅为对照组的一半(P<；0.0 5)。此外，谷氨酰胺被氧化为二氧化碳的速率是葡萄糖的三倍。吲哚美辛促进中性Na+转运，而阿米洛利、前列腺素E2和无氯溶液则抑制谷氨酰胺诱导的中性Na+转运。结论：谷氨酰胺刺激的中性Na+吸收是由前列腺素敏感的心尖部Na+-H+交换机制介导的。谷氨酰胺的Na+-H+交换和组织氧化的增强表明，谷氨酰胺在口服补液液中的应用优于葡萄糖。
Background/Aims:Recent studies of piglet cryptosporidiosis showed an injury-induced impairment of sodium-glucose cotransport and a prostaglandin-mediated inhibition of neutral NaCl absorption. Because glutamine has been shown to stimulate both neutral and electrogenic Na+absorption, this study examined the mechanism of prostaglandin-mediated inhibition of NaCl absorption and the effect of glutamine on these processes.Methods:Ileal mucosa from control and infected pigs was mounted in Ussing chambers for flux studies or incubated with [14C]glutamine or [14C]-glucose for metabolism studies.Results:Glucose and glutamine induced equivalent increases, 2–2.5 μEq·cm−2·h−1, in Na+absorption and short-circuit current in control ileum. Despite a reduction in villous surface area to one third of the control, glutamine enhanced both neutral and electrogenic Na+absorption in the infected ileum by 3.5 ± 0.5 μEq·cm−2·h−1, whereas glucose was only half as effective (P< 0.05). In addition, glutamine was oxidized to CO2at rates three times those of glucose. Indomethacin enhanced, whereas amiloride, prostaglandin E2, and Cl-free solutions inhibited the glutamine-induced neutral Na+transport.Conclusions:Glutamine-stimulated neutral Na+absorption is mediated by a prostaglandin-sensitive apical Na+-H+exchange mechanism. The heightened Na+-H+exchange and tissue oxidation of glutamine suggest that glutamine is superior to glucose for use in oral rehydration solutions.