Acta Physiologica 43. (1973)
3. szám - PHYSIOLOGIA - Kerner J.-Sándor A.-Alkonyi I.: Physiological Variations in Carnitine Acetyl-Transferase Activity in Rat Tissues: Activity in Animals Exposed to Fasting and Cold
CARNITINE ACETYL-TRANSFERASE ACTIVITY 229 ' Table I Effect on CAT activity of fasting and cold adaptation (mean ± S.E.) U: unit of enzyme = 1 /<M of substrate transformed per minute at 25° C Calculation of total unit: weight of organ in gxU/g of wet tissue * p < 0.02; ** p < 0.01; + p < 0.02; ++ p < 0.02 For further details, see chapter on Methods of the enzyme im the whole organ remained unchanged. No change took place in the kidneys or in the interscapular brown fat. As a result of four-week adaptation to cold exposure, a certain increase in activity could be observed in the three organs investigated. In the liver this change was statistically significant, and quite considerable in the interscapular brown fat. The value in the latter tissue was 210% of the controls (U/l g of wet tissue) and 167% with respect to specific activity (U/mg of Group Number of animals Organ U/g of wet tissue U/mg of protein X 10* Total of units Control5 skeletal muscle 2.86 +0.39 25.4 ± 2.9— 5 liver 0.408 ± 0.007“ 1.95 ± 0.16“ 3.27 ± 0.28 5 brown fat 13.97 ±0.79* 95.5 ± 7.62 1.22 ± 0.08 5 kidney 5.10 ± 0.72 47.7 ± 6.2 5.31 ± 0.28 Fasted5 liver 0.610 ± 0.012 2.85 ± 0.22 3.32 ± 0.31 5 brown fat 13.6 ± 0.69 102,1 + 9.2 1.20 ± 0.07 5 kidney 5.10 ± 0.78 48.9 + 7.4 4.60 ± 0.80 Cold-adapted5 skeletal muscle 3.06 ±0.51 27.0 ± 4.5— 5 liver 0.572 ± 0.038** 2.60 ± 0.15“ 5.18 ± 0.36 5 brown fat 29.3 ± 5.6* 158.7 ±21.1* 12.13 ± 1.85 Fig. 1. CAT enzyme activity in interscapular adipose tissue of rats kept at 5°C for different periods. Each value represents the average of data for five animals. The vertical lines indicate the range of values 3* Acta Physiologica Academiae Scientiarum Hungaricae 43, 1973