Growth hormone-binding protein-related immunoreactivity in the serum of patients with acromegaly is regulated inversely by growth hormone concentration.
In this report we describe a newly developed radioimmunoassay (RIA) for the determination of the high-affinity growth hormone-binding protein (GHBP) in human blood. Using this RIA for the measurement of GHBP in serum of 29 patients with acromegaly, decreased concentrations were found compared to the normal range, depending on the activity of the disease. Growth hormone-binding protein was correlated inversely to log GH (r = -0.7, p < 0.001). A weaker relationship was shown between the GHBP activity determined in a functional assay based on charcoal separation and log GH (r = -0.51, p < 0.01). While insulin-like growth factor I (IGF-I) and IGF binding protein 3 (IGFBP-3) were correlated directly to log GH (r = 0.77 and r = 0.66, p < 0.001), an inverse and weaker relationship was evident between GHBP measured by RIA and IGF-I or IGFBP-3 (r = -0.61 and r = -0.57, p < 0.01). In contrast, no correlation could be detected between data of the functional GHBP assay and IGF-I or IGFBP-3.(ABSTRACT TRUNCATED AT 250 WORDS)
Kratzsch
J
J
Department of Clinical Chemistry, University of Leipzig, Germany.
Blum
W F
WF
Ventz
M
M
Selisko
T
T
Birkenmeyer
G
G
Keller
E
E
D000172:Acromegaly / Q000097:blood*; D000328:Adult; D000367:Age Factors; D000368:Aged; D002352:Carrier Proteins / Q000097:blood*; D005260:Female; D013006:Growth Hormone / Q000097:blood*; D006801:Humans; D018969:Insulin-Like Growth Factor Binding Proteins; D007334:Insulin-Like Growth Factor I / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D011863:Radioimmunoassay; D012016:Reference Values
D002352:Carrier Proteins; D018969:Insulin-Like Growth Factor Binding Proteins; D007334:Insulin-Like Growth Factor I; D013006:Growth Hormone; C051815:somatotropin-binding protein