Growth Inhibition in Bone and Bone Marrow Following Treatment With Adrenocorticotropin (Acth)

The action of ACTH on the tibia of immature rats has been studied by Becks, Simpson, Li and Evans (1944) and by Becks, Simpson, Marx, Li and Evans (1944). These workers observed retardation of chondrogenesis and osteogenesis to follow treatment of immature rats with ACTH. Likewise, ACTH antagonized the action of growth hormone when both were injected inbo hypophysectomized rats. The experiments now being reported supplement these observations by adding information regarding the action of ACTH on the bones of (1) adult rats, (2) under varied dietary conditions controlled by tube feeding and (3) at higher dose levels. In addition, the effect of ACTH on the bone marrow and vertebrae will be discussed. materials and methods The general plan of attack for these experiments has been outlined in detail elsewhere (Baker, Ingle, Li and Evans, 1948). Adult male rats (Sprague-Dawley strain) were force-fed diets high in carbohydrate, fat or protein.