The ability of rainbow trout liver cells to regulate their intracellular pH (pHi) was studied using two methods on hepatocytes isolated by collagenase digestion: (i) by monitoring pHi with the fluorescent dye BCECF-AM, and (ii) by measuring the amiloride-sensitive uptake of 22Na, which represents Na+/H+ exchange. In low-Na+ medium (¾16mmoll-1), Na+ uptake was reduced by approximately 70% in the presence of amiloride derivatives (DMA or MPA, 10(-4)moll-1). Changing separately either the extracellular pH (pHe) or the intracellular pH (pHi, clamped by treating the cells with nigericin in the presence of 140mmoll-1 K+) between 6 and 8 induced an increase in the rate of Na+ uptake when pHe was raised or when pHi was reduced. When transferred to hypertonic medium, hepatocytes shrank to nearly 72% of their initial volume, and thereafter a slow and partial regulatory volume increase phase was observed, with an increase in the amiloride-sensitive rate of Na+ uptake and an increase in intracellular pH. As DIDS-sensitive Cl- uptake was concomitantly enhanced, it is suggested that hypertonic stress activates Na+/H+ and Cl-/HCO3- exchange.
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JOURNAL ARTICLE| 01 September 1997
Na+/H+ exchange and osmotic shrinkage in isolated trout hepatocytes
Online Issn: 1477-9145
Print Issn: 0022-0949
J Exp Biol (1997) 200 (17): 2369–2376.
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B Fossat, J Porthé-Nibelle, S Pedersen, B Lahlou; Na+/H+ exchange and osmotic shrinkage in isolated trout hepatocytes. J Exp Biol 1 September 1997; 200 (17): 2369–2376. doi: https://doi.org/10.1242/jeb.200.17.2369
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