To the Editor:—
In the editorial comment in The Journal on "Hormone Metabolism in the `Target' Organs," November 8, page 646, I was surprised to see no reference to the fate of pancreatic secretion and cholecystokinin following intravenous injection of these hormones. In these two instances, the hormones seem not to be "consumed in a reaction in the receptor organ" (target organs) but on the results of the investigation of Greengard, Stein and Ivy (Am. J. Physiol.132:305 [Feb.] 1941; 133:121 [May] 1941, and 134:733 [Nov.] 1941) to be destroyed in plasma of the blood by two substances of enzymatic nature, dubbed "secretinase" and "cholecystokinase" respectively. Perhaps this work failed to fit the thesis of the editorial.