A study of the tissue distribution of adenosine deaminase in six mammal species

1. 1. Comparative studies of the activity of adenosine deaminase in the organs of rat, guinea-pig, mouse, cat, rabbit, dog, and some bovine tissues with substrates adenosine and deoxyadenosine, together with pH optima and isoelectric point studies and in some cases electrophoretic data are consistent with the view that the different organs of a species have a common enzyme but that different enzymes are present in each species. 2. 2. Deaminase activity is high in the spleen and duodenum of all species. In some species lung, ovary and placenta are also highly active. 3. 3. Deaminase activity is low in the blood, brain, muscle, pancreas and testis of all species.