Liver metabolites in resting and exercising rats at 1 and 4 bar

Groups of six rats were put into a compression chamber and exposed to an air pressure of 4 bar or remained at 1 bar. Half of each group was forced to swim in a tank of warm water; the other half remained at rest. A total of 28 rats was used. After 30 min the rats were killed, and part of the liver was rapidly (less than 10 s) removed and pressed between metal plates that had been cooled in liquid nitrogen. Analyses of the metabolites indicated a significant reduction gluconeogenesis in the animals exercising under pressure, probably due to a diminished return of substrates from the muscles. There also appeared to be the possibility of enzymatic control between fructose 6-phosphate and the triose phosphates.