Growth hormone-binding proteins of human serum: developmental patterns in normal man.

Abstract

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.

Serum levels of growth hormone binding protein in children with normal and precocious puberty: relation to age, gender, body composition and gonadal steroids

“…Our findings in healthy children are in accordance with most previous reports in which it has been suggested that the childhood‐related increase in GHBP occurs primarily in prepuberty (Silbergeld et al ., 1989; Massa et al ., 1992a; Merimee et al ., 1992; Martha et al ., 1993). In contrast, Carlsson and coworkers have reported a significant increase in GHBP serum levels in puberty in their study of 733 healthy children (Carlsson et al ., 1994).…”

Physiology and pathophysiology of growth hormone-binding protein: Methodological and clinical aspects

“…In newborns GHBP levels are very low until to 2-6 months of life, followed by a more steep increase up till age 2 years and a more gradual increase throughout childhood with maximum levels attained in early adulthood [73,[133][134][135]. Different and in part opposing correlations are described between GHBP and various measures of growth in children.…”