Increased insulin receptor binding in erythrocytes from growth hormone-deficient children.
Erythrocytes from growth hormone-deficient children (GHd-children) (n = 10) showed a statistically significant increase in insulin binding at low unlabeled insulin concentrations, together with a threefold decrease in apparent receptor affinity, as compared to control children (C) (n = 11). Scatchard analysis of the binding data using the two-site model revealed that both the receptor concentration R1 [GHd-children 0.10 +/- 0.01 ng/ml and C 0.03 +/- 0.002 ng/ml] and the dissociation constant KD1 [GHd-children (0.48 +/- 0.05) x 10(-9) M and C (0.19 +/- 0.01) x 10(-9) M] for high affinity-low capacity sites were significantly increased in erythrocytes from GHd-children, while neither receptor concentrations (R2) nor the dissociation constant (KD2) for low affinity-high capacity sites proved to be altered. These events were accompanied by a normal sensitivity to insulin as well as glucose tolerance in the GHd-group. The meaning of the increased insulin binding with normal insulin sensitivity in GH-deficiency is discussed.
Dávila
N
N
Servicio de Endocrinología, Universidad Autónoma de Madrid, Spain.
Barceló
B
B
Carranza
M C
MC
Calle
C
C
D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D004912:Erythrocytes / Q000378:metabolism*; D005260:Female; D005951:Glucose Tolerance Test; D013006:Growth Hormone / Q000172:deficiency*; D006801:Humans; D007328:Insulin / Q000378:metabolism; D007333:Insulin Resistance; D008297:Male; D011972:Receptor, Insulin / Q000378:metabolism*
D007328:Insulin; D013006:Growth Hormone; D011972:Receptor, Insulin