Growth hormone-binding proteins of human serum: developmental patterns in normal man.
The binding of GH by a low affinity binding protein (LA-BP) was measured from birth into adulthood and compared with binding of a high affinity binding protein (HA-BP) in human serum. Pooled serum samples for each year of age from birth to 16.5 yr were formed from 2500 separate samples and assayed for both binding proteins using a Sephadex chromatographic method. Individual samples in this age range and those from adults were assayed in a similar manner. Binding of [125I]GH was minimal by both binding proteins in cord blood (binding by LA-BP, 2.77 +/- 0.32%; binding by HA-BP, 2.58 +/- 0.35% mean +/- SEM). A 4-fold increase to maximal binding for LA-BP occurred by the age of 5 yr and remained relatively constant through adolescence, except for a transient decrease at puberty. From 16.5-20 yr of age, binding by LA-BP decreased to a level no greater than that seen at birth. Binding by the HA-BP, which increased 6- to 8-fold reached maximal binding between 23-25 yr of age. Binding by HA-BP did not decrease in adults between the ages of 20-30 yr. Whereas pregnancy increased LA-BP activity, GH binding by HA-BP was unaltered.
Merimee
T J
TJ
Department of Medicine and Metabolism, University of Florida, Gainesville 32610-0226.
Russell
B
B
Quinn
S
S
D000293:Adolescent / Q000502:physiology*; D000328:Adult; D000375:Aging / Q000097:blood*; D000818:Animals; D001667:Binding, Competitive; D044383:Black People; D001827:Body Height; D002352:Carrier Proteins / Q000097:blood*; D002648:Child; D002657:Child Development; D002675:Child, Preschool; D005260:Female; D013006:Growth Hormone / Q000378:metabolism; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D011247:Pregnancy / Q000097:blood; D012016:Reference Values
D002352:Carrier Proteins; D013006:Growth Hormone; C051815:somatotropin-binding protein