Samples of left ventricle and deltoid muscle, obtained immediately upon nembutal anesthesia of 6 dogs, were heated 5 mins. in boiling water, homogenized and analyzed for cocarboxylase and coenzyme I. Second samples were analyzed 1 hr. later. During this hr. the dog and excised heart remained at room temp. Cocarboxylase was detd. manometrically and coenzyme by Gregg''s modification of the method of Axelrod and Elvehjem. The results showed a surprising lack of breakdown of the compounds tested.