Beach R E, Schwab S J, Brazy P C, Dennis V W
Am J Physiol. 1987 Feb;252(2 Pt 2):F215-20. doi: 10.1152/ajprenal.1987.252.2.F215.
We studied the effects of norepinephrine on solute transport and oxidative metabolism in proximal tubules. Norepinephrine (10(-6) M) in the bath stimulated fluid absorption (Jv) by proximal convoluted tubules from 0.76 +/- 0.10 to 1.01 +/- 0.11 nl X mm-1 X min-1 (P less than 0.001). Bicarbonate, chloride, and phosphate transport also increased in proportion to the increases in Jv. Norepinephrine increased ouabain-sensitive oxygen consumption (QO2) in suspensions of cortical tubules by 1.3 nmol X mg protein-1 X min-1 and had no effect on ouabain-insensitive QO2 or mitochondrial respiration. Na+-K+-ATPase activity in basolateral membranes prepared from cortical homogenates incubated with norepinephrine increased from 277.1 +/- 34.9 to 411.1 +/- 38.6 nmol Pi X mg protein-1 X min-1 (P less than 0.005). Norepinephrine also increased Na+-K+-ATPase activity of cortical homogenates by 72% but had no effect on Na+-K+-ATPase if added directly to purified basolateral membranes. These studies show that norepinephrine stimulates solute transport in the proximal tubule by increasing Na+-K+-ATPase activity indirectly through some component or components of the adrenergic receptor system.
我们研究了去甲肾上腺素对近端肾小管溶质转运和氧化代谢的影响。浴液中10⁻⁶M的去甲肾上腺素可使近曲小管的液体吸收（Jv）从0.76±0.10增加至1.01±0.11 nl·mm⁻¹·min⁻¹（P＜0.001）。碳酸氢盐、氯离子和磷酸盐的转运也与Jv的增加成比例增加。去甲肾上腺素使皮质肾小管悬液中哇巴因敏感的氧消耗（QO₂）增加1.3 nmol·mg蛋白⁻¹·min⁻¹，对哇巴因不敏感的QO₂或线粒体呼吸无影响。用去甲肾上腺素孵育的皮质匀浆制备的基底外侧膜中的Na⁺-K⁺-ATP酶活性从277.1±34.9增加至411.1±38.6 nmol Pi·mg蛋白⁻¹·min⁻¹（P＜0.005）。去甲肾上腺素还使皮质匀浆的Na⁺-K⁺-ATP酶活性增加72%，但直接添加到纯化的基底外侧膜时对Na⁺-K⁺-ATP酶无影响。这些研究表明，去甲肾上腺素通过肾上腺素能受体系统的某些成分间接增加Na⁺-K⁺-ATP酶活性，从而刺激近端肾小管中的溶质转运。
