Tissue Hypertrophy: A Quantitative Adaptational Strategy During Cold Acclimation in Channel Catfish and Green Sunfish (Immunoelectrophoresis, Heart, Liver, Protein Synthesis, Degradation)

278 p.Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1986.1. Livers of 15 C acclimated channel catfish (CCF) exhibit cellular hypertrophy compared to livers of 25 C acclimated catfish as shown by doubling of hepatosomatic index (HSI) and total liver protein. No change occurs in protein concentration or total liver DNA. The same pattern was observed for heart although the absolute magnitude of hypertrophy was no more than 20-30%.2. Enzyme specific activities of liver show considerable variability between acclimation groups; Cytochrome oxidase (Cytox) and lactic dehydrogenase (LDH) show inverse acclimatory patterns; citrate synthase (CS), glucose-6-phosphate dehydrogenase (G6PDH) and 6-phosphogluconic dehydrogenase (6-PGDH) show positive compensatory patterns. Activities expressed on either total liver or DNA were approximately double those based on protein and paralleled alterations in HSI and total protein. This effectively doubled enzyme catalytic capacities at the low acclimation temperature, exceeding alterations in specific activities.3. Seasonal acclimatization of CCF to spring, summer, fall, and winter conditions mimics differences observed in acclimated CCF. The seasonal response may be more complex in that hyperplasia may additionally occur owing to more complex environmental interactions other than temperature.4. Time-course changes in HSI and total liver protein content for fish transfered at intervals from either 15 to 25 C or 25 to 15 C were reciprocal for both parameters. Calculations of protein degradation and synthesis suggest that protein synthesis is more temperature sensitive and may be more important in altering protein levels than degradation.5. In green sunfish, time-course changes in HSI, total protein, and glycogen following transfer of fish from 15 to 25 C showed a transient decline, but no persistent change in HSI, and a 50% reduction in total protein; glycogen was increased and compensated for the reduction in total protein. In contrast, CCF showed parallel changes in HSI and total protein content and a reduction in glycogen content at 25 C.6. Relative concentrations of cytox, G6PDH and LDH-A4 were assessed between 15 and 25 C acclimation groups using rocket immunoelectrophoresis and antibodies (Abs) generated against the above proteins and against cytoplasmic and mitochondrial fractions from fish liver. All three enzymes showed consistent alterations in cellular concentration and activity, although each enzyme demonstrated a characteristic response to low temperature acclimation.U of I OnlyRestricted to the U of I community idenfinitely during batch ingest of legacy ETD