Recently much interest has been shown in the inhibition of respiration induced by glucose addition to cells. This inhibition is often called the reversed or inverted Pasteur effect or the Crabtree effect. In this paper the term Crabtree effect has been utilized to describe the inhibition observed after the addition of any hexose or hexose analog capable of inhibiting respiration in any tissue. Unfortunately, the studies on the Crabtree effect are scattered throughout a large variety of journals and often appear incidental to other work. This review is an attempt to bring many of the publications which deal with the Crabtree effect together so that it might be easier to visualize the scope, mechanism, and possibly the meaning of this competition between catabolic pathways. Apparently, no previous attempt has been made to review this field of interest.

THE CHARACTERISTICS OF THE EFFECT IN EHRLICH ASCITES TUMOR CELLS Although work had been done since 1929, when Crabtree (~ 4) first reported the effect, modern workers were stimulated by the publications of El'tsina and Seitz (31) and Kun et al.(56). Both of these groups of investigators employed the Ehrlich ascites tumor cell, and since then the majority of recent studies on the Crabtree effect have been made with this cell. Therefore, it is convenient to refer to results obtained with the Ehrlich cells as a standard of comparison. Respiratory inhibition can be induced by glucose, fructose, mannose (1~, 21, 56, 80, 88) and'2-deoxyglucose (48, 76). The course of inhibition Received for publication March 0, 1961.