Serum and urine somatomedin B in pediatrics.

Somatomedin B was determined by the radioimmunological method in the serum and urine of 104 normal subjects divided into seven age groups. The serum and urine of each patient were divided into two fractions of which one was heated at 60 degrees C for 30 min. SmB serum levels were significantly higher in heated than in unheated samples in all age groups.