93 INCREASE IN SPECIFIC BINDING (SB) OF ERYTHROCYTE (RBC) RECEPTORS FOR INSULIN-LIKE GROWTH FACTOR 2 (IGF-2) WITH GROWTH HORMONE TREATMENT OF HYPOPITUITARY CHILDREN

Abstract

Specific receptor binding for IGF's is measurable in younger (lighter) RBC's. An aliquot of such cells of similar age (fraction A), can be reproducibly obtained by dextran gradient centrifugation from 5-10 ml of blood.(JCEM 1983 57: 436). We now report IGF-2 SB to these RBC's from normal children and those with growth hormone deficiency (GH def.). Inter- and intra-assay variability of the procedure is 11%. The per cent of total RBC's in fraction A did not differ in the 2 groups of children. Normals (Group 1), were 5 male volunteers (14.7± .6 yr, Mean and SEM) and 10 children (3 female) with constitutional short stature (11.4± 1.6yrs) who had normal 6 hr GH profiles and plasma IGF-1 values. 11 GH def. children (Group 2), aged 12.7 ± 1.4yr,(6 girls),had samples taken after 2 mos without hGH therapy (2a), and again during 10 mos of hGH (2U,3/wk) (2b).