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Hepatocellular Na + /H + exchange is activated early, transiently and at a posttranscriptional level during rat liver regeneration
Author(s) -
Dällenbach Andreas,
Marti Ulrich,
Renner Eberhard L.
Publication year - 1994
Publication title -
hepatology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.488
H-Index - 361
eISSN - 1527-3350
pISSN - 0270-9139
DOI - 10.1002/hep.1840190530
Subject(s) - intracellular ph , intracellular , liver regeneration , hepatectomy , chemistry , in vivo , medicine , microbiology and biotechnology , biochemistry , endocrinology , biology , regeneration (biology) , surgery , resection
In hepatocytes in vitro, Na + /H + exchange, an important regulator of intracellular pH, is activated by epidermal growth factor, but its activity during liver regeneration in vivo is unknown. We therefore compared activity and regulation of Na + /H + exchange in hepatocytes isolated after two‐thirds partial hepatectomy or sham surgery, respectively, by measuring intracellular pH (fluorimetry) and steady state Na + /H + exchange mRNA levels (Northern blotting). Resting intracellular pH increased from 7.06 ± 0.02 to 7.12 ± 0.02 (p<0.05) 2 hr but not 20 hr after partial hepatectomy. Na + /H + exchange–mediated rates of intracellular pH recovery from an acid load increased from 0.075 ± 0.018 to 0.151 ± 0.018 pH units/min (p<0.05) 2 hr but not 20 hr after partial hepatectomy. Because intracellular buffering capacity was not affected, this reflects increased Na + /H + exchange activity. The inverse relationship between Na + /H + exchange activity and intracellular pH was shifted by about 0.1 pH units toward more alkaline pH values 2 hr but not 20 hr after partial hepatectomy, whereas steady‐state Na + /H + exchange mRNA levels remained unchanged. In conclusion, hepatocellular Na + /H + exchange is activated early, transiently and at a posttranscriptional level during liver regeneration induced in the rat by partial hepatectomy. (H EPATOLOGY 1994;19:1290–1301.)