[Activity of blood somatomedin during childhood in normal subjects and in delayed growth].

A hundred sera from children, were used to evaluate normal levels of somatomedin activity and pathological levels. The results showed that the level of this activity in the blood, rises gradually during infancy, to reach normal adult reference level by postulate, equal to 1. Although the values are widely dispersed in each sample, the general phenomenon of their increase in infancy remains significant. The patients with somatotropin deficiency, have very low somatomedin values which become normal under the influence of injection of human growth hormone. A very unusual case is that of Laron's dwarfism with very high values of HGH in the plasma, and very low levels of somatomedin and, clinical and laboratory indifference to injections of exogenous HGH. The prospects of progress in the techniques of study of somatomedin will be of great service in the near future.