Quantitative estimation of amineoxidase

THE evidence linking brain function to amineoxidase activity1 has stimulated a large production of papers2. The disagreements that have ensued2 might well be a measure of the interest in these aminases. However, we attribute much of the discord to the accepted method of studying these trace enzymes, namely, respirometry. The present communication shows that respirometry is an erratic yardstick as compared with the measurements of ammonia (or primary amine) released by the amineoxidase reaction. The ease and accuracy of these latter micromethods have been shown previously3–9.