AbstractsBiology & Animal Science

Thirty years of intensive research have demonstrated the importance of the physiological role played by the steroids. The more recent investigations relating to the hormones of the adrenal cortex, which have led to the use of synthetic steroids in the treatment of diseases of mal-adaptation, represent a crowning achievement of the co-operation of the biological and chemical sciences. Yet, these remarkable discoveries should not, in any way, obscure the enormous gaps in our knowledge of the metabolism of these substances, but should instead pave the way to a thorough study of the many problems that remain to be solved. Many factors have been responsible for the great difficulties encountered during the study of the intermediary metabolism of the steroids. The complicated chemical structure of the molecules and the presence of only minute quantities of the hormones in biological materials account for some of these obstacles; the occurrence of a large number of closely related compounds in the same tissues, organs and excreta as well as their rapid synthesis and degradation account for others. In practice, these difficulties were clearly demonstrated by the fact that only a small fraction of an administered dose of a steroid could be recovered from the experimental animal and its excretory products. Thus little reliable and coherent information regarding the biochemical transformations of these substances could be gained prior to the use of isotopes. [...]