Chan Y L
Pflugers Arch. 1980 Nov;388(2):159-64. doi: 10.1007/BF00584122.
The effects of norepinephrine and phenoxybenzamine on bicarbonate absorption in the rat proximal convoluted tubules were studied by simultaneous microperfusion of tubule and peritubular capillaries. Bicarbonate was determined by using a pH-sensitive membrane electrode system. The rates of bicarbonate absorption (JHCO3) were examined in the same proximal tubule before and after the addition of norepinephrine or phenoxybenzamine. When the proximal tubule was perfused with Ringer solution and peritubular capillaries were perfused with albumin Ringer solution, JHCO3 was 145 +/- 3.3 pEq/min X mm. Addition of 2 X 10(-6) mol/l norepinephrine to the capillary perfusate caused a 21% increase in JHCO3. Addition of 2 X 10(-6) mol/l phenoxybenzamine to the capillary perfusate caused a 12% decrease in JHCO3. Addition of both norepinephrine and phenoxybenzamine to the capillary perfusate caused a 19% decrease in JHCO3. However, there was no significant effect on JHCO3 observed when either norepinephrine or phenoxybenzamine was added to the luminal perfusate. These results suggest that adrenergic nerves participate in the regulation of renal tubular bicarbonate absorption through the direct action of norepinephrine on adrenergic receptors located at the basolateral side of the proximal tubule.
通过同时对肾小管和肾小管周围毛细血管进行微量灌注，研究了去甲肾上腺素和酚苄明对大鼠近端曲管中碳酸氢盐吸收的影响。使用pH敏感膜电极系统测定碳酸氢盐。在添加去甲肾上腺素或酚苄明之前和之后，在同一近端小管中检测碳酸氢盐吸收速率（JHCO3）。当近端小管用林格溶液灌注且肾小管周围毛细血管用白蛋白林格溶液灌注时，JHCO3为145±3.3 pEq/分钟×毫米。向毛细血管灌流液中添加2×10（-6）mol/L去甲肾上腺素导致JHCO3增加21%。向毛细血管灌流液中添加2×10（-6）mol/L酚苄明导致JHCO3降低12%。向毛细血管灌流液中同时添加去甲肾上腺素和酚苄明导致JHCO3降低19%。然而，当向管腔灌流液中添加去甲肾上腺素或酚苄明时，未观察到对JHCO3有显著影响。这些结果表明，肾上腺素能神经通过去甲肾上腺素对位于近端小管基底外侧的肾上腺素能受体的直接作用参与肾小管碳酸氢盐吸收的调节。
