Tissue activities of enzymes of diagnostic interest in the marmoset and rat.

The activities of enzymes of diagnostic interest were investigated in the liver, heart, kidney and muscle of the marmoset (Callithrix jacchus) and the rat. Methods of tissue extraction which gave maximal enzyme activity were used and comparison between the species showed some major differences. AST, LDH and GDH showed a similar distribution in both species but ICDH activity was much higher in the rat heart than in any other rat or marmoset organ. ALP, LAP and GGT were present in much higher activities in the rat kidney than in the marmoset kidney, a finding which was reversed in the liver of these animals. The major ALT-containing organ in the rat was the liver but, in the marmoset, this enzyme was found in relatively large quantities in the heart and muscle also. These differences can be of importance when plasma enzyme activities are measured following tissue damage.