Na-H exchange regulates intracellular pH in isolated rat hepatocyte couplets.

摘要: Intracellular pH (pHi) was measured directly in isolated rat hepatocyte couplets using sensitive microelectrodes. The hepatocytes were maintained a minimal salt buffer without added hormones or serum. Values of pHi (6.99 +/- 0.12, mean SE) close to their Nernst equilibria. After intracellular acidification with ammonium chloride, regulation inhibited 1 mM amiloride by omission external sodium, consistent Na-H exchange mechanism. Mean buffering power, the nominal absence carbon dioxide, 34.1 11.4 mM. In presence bicarbonate, sodium slowed, but did not completely inhibit recovery from acidification, indicating that additional mechanisms may operate this preparation. These studies provide direct measurement and indicate exchange, together bicarbonate dependent system are important for