Hemoglobin Maintenance and Production Upon Synthetic Diets, Including Modifications in the Ethyl Xanthate and Biazzo Methods for Copper Analysis. I

The point of view, developed mainly by Whipple and Robscheit-Robbins (l), that certain foodstuffs possess special virtuesascurative agents in experimental secondary anemia has been generally accepted.In recent years great strides have been made in nutritional research by the use of so called synthetic diets, composed in large part of purified food constituents.It seemed pertinent, therefore, to inquire whether a synthetic diet, which has been shown to maintain experimental animals in apparent health, is also a maintenance diet in respect to hemoglobin.The primary object of this investigation was put in the question: Will animals fed exclusively upon synthetic diets over long periods of time maintain hemoglobin at a normal level?During the course of this work there were published the very interesting papers of Hart and his associates (2) upon the importance of the salts of copper in the cure of severe anemia in rats due to an exclusive milk diet.While not losing sight of the original purpose of the problem, we deemed it advisable to gain, if possible, further information concerning the signi&ance of copper in hemoglobin formation.About a year ago a preliminary report (3) was made upon the early part of this work.The copper analyses, which were the basis for the interpretation of the results, were by the ethyl xanthate method (4).Simultaneously with the publication of this note, Elvehjem and Lindow (5) gave up the use of the ethyl xanthate method and introduced a slightly modified Biazzo technique for 51