大鼠小肠中的钠泵与己糖转运及代谢的关系

Sodium pumps in the rat small intestine in relation to hexose transfer and metabolism.

Barry R J, Eggenton J, Smyth D H

J Physiol. 1969 Oct;204(2):299-310. doi: 10.1113/jphysiol.1969.sp008914.

Abstract

The nature of Na transfer across rat jejunum was studied by measuring the Na and fluid transfers and the electrical potential in the presence of galactose, mannose and glucose.2. Galactose, actively transferred but not metabolized, caused an increase in the potential but no change in Na transfer or tissue resistance.3. Mannose, not actively transferred but metabolized, caused a large increase in Na and fluid transfer without affecting the potential or tissue resistance. Similar results were obtained with glucose in the presence of phlorrhizin.4. Galactose in the presence of mannose increased fluid and Na transfer to the level found with glucose, which is both actively transferred and metabolized.5. These results are consistent with the view that there are two Na pumps associated with hexoses in rat jejunum, both moving Na towards the serosal side. One is an electrogenic pump, stimulated by hexose transfer, and which results in a rise in potential, and the other is a neutral pump which is stimulated by hexose metabolism and which does not affect the potential.

摘要

通过在半乳糖、甘露糖和葡萄糖存在的情况下测量钠和液体转运以及电势，研究了钠在大鼠空肠中的转运性质。
半乳糖被主动转运但不被代谢，导致电势升高，但钠转运或组织电阻没有变化。
甘露糖不被主动转运但被代谢，导致钠和液体转运大幅增加，而不影响电势或组织电阻。在根皮苷存在的情况下，葡萄糖也得到了类似的结果。
半乳糖在甘露糖存在的情况下，使液体和钠转运增加到与葡萄糖相同的水平，葡萄糖既被主动转运又被代谢。
这些结果与以下观点一致：在大鼠空肠中，有两个与己糖相关的钠泵，都将钠向浆膜侧转运。一个是电生泵，受己糖转运刺激，导致电势升高；另一个是中性泵，受己糖代谢刺激，不影响电势。