Fatty acid synthesis in mice during the 24hr cycle and during meal-feeding.

Fatty acid synthesis was measured in liver, adipose tissue and the rest of the carcass in vivo, by measuring the incorporation of 3H from 3H2O. The maximum rate of synthesis during the 24 hr cycle occurred at 21.00-22.00 hr. At all times, the rest of the carcass was the major synthetic site and adipose tissue only made a significant contribution at the time of maximum synthesis. The rate of fatty acid synthesis in meal-fed mice was increased during the meals by 5-8 fold in the rest of the carcass, 10-fold in liver, and 30-60-fold in adipose tissue over the rate of synthesis in the immediate pre-prandial period. It is suggested that one reason for the higher rates of fatty acid synthesis in the rest of the carcass could be the activity of the intramuscular fat pads.