Temperature Acclimation of Enzyme Activities and Protein Synthesis in Channel Catfish (Ictalurus Punctatus). In Vivo and In Vitro Studies

Hepatocytes from 15(DEGREES)C acclimated catfish isolated by collagenase perfusion were maintained for 3-4 weeks in primary culture at 7, 15, and 25(DEGREES)C on biomatrix prepared from liver structural proteins. Specific activities of enzymes of cultured hepatocytes showed acclimatory compensation for the following: cytochrome(DEGREES)C oxidase, citrate synthase, NADH-cytochrome(DEGREES)C reductase, and glucose-6-phosphate dehydrogenase. Lactate dehydrogenase showed no compensation. 6-phosphogluconate dehydrogenase showed partial inverse compensation. Hence, cultured hepatocytes show temperature acclimation of enzymes in patterns similar to those measured in vivo. Protein synthesis measured at 15(DEGREES)C by hepatocytes from catfish acclimated to different temperatures occurred in the series: 7 > 15 > 25(DEGREES)C acclimation. Protein synthesis measured at 15(DEGREES)C by cultured hepatocytes occurred in the series: 15 > 7 > 25(DEGREES)C. Protein degradation measured at temperatures of culture occurred in the series: 25 > 15 > 7(DEGREES)C. Changes in concentration of enzymes during acclimation may occur by direct temperature effects on rates of synthesis and degradation, and differences in temperature effects on protein synthesis in vitro and in vivo may result from absence of some critical substance in culture.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Physiology

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2014

Author dc:creator

• Koban, Michael

• Biology, General

Identifier

(UMI)AAI8502206

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/71432