Austin C, Wray S
Physiological Laboratory, University of Liverpool, UK.
Pflugers Arch. 1995 Jan;429(3):325-31. doi: 10.1007/BF00374146.
Intrinsic buffering power (beta i) has been measured in vascular strips and single cells from rat mesenteric artery. Intracellular pH (pHi) regulation was inhibited to prevent overestimation of beta i due to acid extrusion or entry via regulatory processes. At resting values of pHi (7.0-7.2), a mean value of 41 +/- 4 mM/pH unit for beta i was found. beta i increased approximately fivefold from 30 to 150 mM/pH unit over the pHi range 7.5-6.5. The mean data relating beta i to pHi could be described by relating beta i to buffer concentrations and pKa. This gave a value of 310 mM for buffer concentration and a pKa of 6.0. As changes in pHi are known to have marked effects on vascular tone then the increase in beta i as pHi falls may be considered as a means of attenuating pHi decreases, before pH regulation restores pHi to resting levels.
已在大鼠肠系膜动脉的血管条和单细胞中测量了内在缓冲能力（βi）。细胞内pH（pHi）调节受到抑制，以防止由于酸通过调节过程挤出或进入而导致βi的高估。在pHi的静息值（7.0 - 7.2）下，发现βi的平均值为41±4 mM/pH单位。在pHi范围7.5 - 6.5内，βi从30 mM/pH单位增加到150 mM/pH单位，增加了约五倍。将βi与pHi相关的平均数据可以通过将βi与缓冲液浓度和pKa相关来描述。这得出缓冲液浓度值为310 mM，pKa为6.0。由于已知pHi的变化对血管张力有显著影响，那么随着pHi下降βi的增加可被视为在pH调节将pHi恢复到静息水平之前减弱pHi降低的一种方式
