Abstract
The relation between expiratory 14CO2 pattern and dispositional partition of a 14C-carbonacious substrate following intravenous injection of tracer amount to rats was elucidated by radiorespirometic techniques. Two kinds of 14C-methionines and 4 kinds of 14C-glucoses labelled at different positions of their chemical structure were used for this purpose. In case of 2 kinds of 14C-methionines, [carboxyl-14C] and [methyl-14C]methionines, 2 different wave heights of the radiorespirometric patterns were recorded. However, no difference was observed in the wave heights and recovery rates of radioactivity among 4 kinds of 14C-glucoses, which stands completely against the conclusion reported by Dr. Wang. Results indicated that the wave height and recovery rates were responsible for the partition rate of 14C-atoms positioned on the substrate into carbon dioxide during their catabolism in vivo.
