The Growth Hormone-Binding Proteins in Human Serum: Partial Characterization and Regulation

ABSTRACT

We assessed about growth hormone binding proteins (GHBP) activity which was measured eluted biotin GH fraction with alkaline phosphatase-streptavidine in children with insulin dependent diabetes mellitus (IDDM), short stature due to growth hormone deficiency (GHD), chronic renal failure, short stature due to nutritional deficiency. hypothyroidism and normal control groups using high pressure liquid chromatography protein pak 300 sw column. The following results are observed: 1) There were 3 types of growth hormone (GH) in serum: first GH binded with type I (minor) GHBP suggesting 200K dalton of molecular weight, second GH binded with type II (major) GHBP suggesting 60~70K dalton of molecular weight, and third GH were free form GH suggesting 20~25K dalton of molecular weight. 2) Type II (major) GHBP showed considerable individual variation in all ages. Neonates had the lowest levels of GHBP activity, but by the puberty the levels had increased & remained stable from adolescent to adult periods. 3) GHBP activity of children with IDDM at diagnosis was low value as compared to the same agenormal control group (p<0.05), and difference of GHBP activity among children with IDDM was related with height velocity (r=+0.92). Follow up GHBP activity during insulin therapy was reverse correlation with HbAlc. 4) GHBP activity of children with GHD at diagnosis was a slightly low compared to aged matched control and follow-up GHBP activity after 1 dose GH therapy showed increasing tendency (r=-0.68). 5) Otherwise, children with chronic renal failure, short stature due to nutritional deficiency, and hypothyroidism were assessed lower value than normal control group. Above results, GHBP activity had the lowest levels at neonatal period and then increasing tendency until puberty period and remained steady level until adult period. Regulation of GHBP may be closely related with metabolic control state by insulin, GH, nutritional status, and thyroid hormone..