AJP - Regulatory, Integrative and Comparative Physiology, Vol 250, Issue 2 211-R220, Copyright © 1986 by American Physiological Society
Can cultured teleost hepatocytes show temperature acclimation?
M. Koban
Hepatocytes were prepared from 15 degrees C acclimated catfish (Ictalurus
punctatus) and maintained in primary culture for 20 days on biomatrix at 7,
15, and 25 degrees C without hormones or serum to determine if cells can
directly adapt to temperature. Specific activities of cytochrome-c oxidase,
NADH-cytochrome c reductase, citrate synthase, and glucose-6-phosphate
dehydrogenase showed acclimatory rate compensation (7 greater than 15
greater than 25 degrees C cultured); 6-phosphogluconate dehydrogenase had
activity changes of 15 greater than 7 greater than 25 degrees C cultured;
activity of lactate dehydrogenase occurred in the series 7 greater than 15
= 25 degrees C. Protein synthesis of freshly isolated hepatocytes from
catfish acclimated to the three temperatures exhibited acclimatory rate
compensation. In contrast, protein synthesis of cultured hepatocytes
occurred in the series 15 greater than 25 greater than 7 degrees C
cultured. Protein degradation was highest at 25 degrees C followed by cells
at 15 and 7 degrees C. Cultured hepatocytes showed incomplete temperature
acclimation in vitro by way of enzyme activity changes and of protein
synthesis. This suggests that some factor(s), such as hormones, is probably
necessary to mediate the full temperature-acclimation process.
