Glutamic-pyruvic transaminase (GPT) in non-human primates II. Implication of the interspecific variation in enzyme activity

Glutamic-pyruvic transaminase (GPT) in plasma of 25 species of non-human primates including one hybrid species was investigated. There were not such significant differences in plasma GPT activities among species as in red cells. The fact that the enzyme activities of GPT in plasma correlate with those in liver s-GPT and the absence of organspecificity of soluble GPT suggest that the significant differences of GPT activity in red cells among species may probably be specific in red cells and reflect the quantitative differences of the enzyme. Moreover, GPT activity was detectable neither in younger red cells nor in reticulocytes obtained from Japanese monkeys (Macaca fuscata) in which red cell GPT activity could not be detected. Therefore, the significant interspecific variation of GPT activity in red cells may result from that of the enzyme quantity synthesized in red cells.