Shrinkage-induced activation of Na(+)-H+ exchange in barnacle muscle fibers.

  title={Shrinkage-induced activation of Na(+)-H+ exchange in barnacle muscle fibers.},
  author={Bruce A. Davis and Emilia M. Hogan and Walter F. Boron},
  journal={The American journal of physiology},
  volume={266 6 Pt 1},
We examined the effect of shrinkage on Na(+)-H+ exchange in single muscle fibers at intracellular pH (pHi) values of 6.8, 7.2, and 7.6 using pH microelectrodes and internal dialysis. Under normotonic conditions (975 mosmol/kgH2O) at pHi 6.8, the amiloride-sensitive acid-extrusion rate (JAmil/s) averaged 17 microM/min. Exposure to hypertonic solutions (1,600 mosmol/kgH2O) increased JAmil/s to 304 microM/min at pHi 6.8. At pHi approximately 7.2 and 7.6, hypertonicity increased JAmil/s from… CONTINUE READING