STUDIES ON THE ENDOCRINE REGULATION OF THE NUMBER OF CIRCULATING EOSINOPHIL CELLS IN THE RAT

It is obvious that very little is known about the regulation and significance of the eosinophil cells in the blood. An increase in the number of these cells in allergic conditions, in certain infectious diseases and postinfectious conditions, along with an eosinopenia at the beginning of infections, has been known for a long time, but these observations could not be explained, although some connection with the autonomic nervous system has been postulated. New interest in the eosinophil cells was aroused by the demonstration in 1948, of the connection between these cells and the 11-oxycorticosteroids. These hormones, as well as corticotrophin, cause a drop in the number of circulating eosinophil cells both in human subjects and in experimental animals (Forsham et al., 1948). The decrease of the eosinophil cells produced by corticotrophin has been used, along with other tests, in diagnosing hypofunction of the adrenal cortex. A similar decrease could be