AJP - Regulatory, Integrative and Comparative Physiology, Vol 245, Issue 1 32-R37, Copyright © 1983 by American Physiological Society
Intracellular pH-temperature interactions of hepatocytes from American eels
P. J. Walsh and T. W. Moon
The effects of acclimation temperature and acute temperature changes on the
intracellular pH (pHi) of hepatocytes isolated from the American eel,
Anguilla rostrata, were studied by the measurement of the distribution
ratio of dimethyloxizolidinedione (DMO). Varying the concentration of DMO
(10(-7) to 10(-4) M) did not affect estimates of pHi, indicating that DMO
acts as an ideal pHi probe in eel hepatocytes. In vitro studies yielded
values of liver cell pHi identical to those previously measured in vivo (in
vitro pHi = 7.556 +/- 0.010; in vivo pHi = 7.570 +/- 0.049 at 20 degrees
C); hepatocyte pHi varied inversely with acclimation temperature (5-20
degrees C) in a manner consistent with alphastat regulation (delta pH/delta
T = -0.0182 +/- 0.021). During acute temperature increases (5-20 degrees C)
and decreases (20-5 degrees C) hepatocytes regulated pHi to the appropriate
(acclimated) value within 30-45 min posttransfer under conditions of
constant medium pH (pHe). The effects of medium pH were also studied, and
although patterns of pHi regulation differed between 5 and 20 degrees C
cells, a pHi difference consistent with alphastat regulation was maintained
between 5 and 20 degrees C cells over the pHe range 7.8-8.3.
