Growth Hormone Effects on Cartilage Amino Acid Composition

Abstract
Introduction It has been established that administration of growth hormone promotes longitudinal growth of bones associated with increased formation of new cartilage.1-3 This effect of growth hormone is so characteristic that measurement of the dimensions of the epiphyseal cartilage following injection of growth hormone has served as a means of assay of growth hormone.4-6 Growth of cartilage is accomplished, presumably, by increase in either protein content, polysaccharide content, or both. Growth hormone administration results in increased incorporation of administered inorganic S35 into chondroitin sulfate.7-9 Twenty-four hours after the administration of S35 sulfate to intact rats the decline of radioactivity in cartilage as determined by quantitative autoradiography has been found to occur at a rate similar to the decline in radioactivity of the ester sulfate of isolated chondroitin sulfate.10 It appears, therefore, that injection of growth hormone leads to increased synthesis of the polysaccharide moiety