Immunochemiluminometric assays (ICMA) specific for growth hormone releasing hormone 1-44 NH2 and 1-40 OH.
We describe specific two-site immunochemiluminometric assays able to directly measure human growth hormone-releasing hormone 1-44 NH2 and 1-40 OH concentrations in unextracted plasma. A common N-terminal antibody was purified from polyclonal rabbit antisera to growth hormone-releasing hormone 1-44 NH2 on a growth hormone-releasing hormone 1-29 NH2 linked affinity column and labelled with chemiluminescent acridinium ester. C-terminal specific monoclonal antibodies to growth hormone-releasing hormone 1-44 NH2 and 1-40 OH were raised in Balb/C mice and used as solid phase antibodies. Assay of fasting specimens from normal individuals gave medians (and ranges) of 23 pg/ml (2-200) and 30 pg/ml (3-134) for growth hormone-releasing hormone 1-44 NH2 and 1-40 OH, respectively. Samples from a series of acromegalics showed that most have values in the normal range though median values were higher, 56 pg/ml for growth hormone-releasing hormone 1-44 NH2 (P < 0.001) and 52 pg/ml for 1-40 OH (P < 0.001). Using these assays it will be possible for the first time to directly study the physiology and pathophysiology of these two peptides.
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M D
MD
Department of Medicine, University of Wales College of Medicine, Cardiff, UK.
Edwards
C A
CA
Brown
R
R
Weeks
I
I
Woodhead
J S
JS
Scanlon
M F
MF
D000172:Acromegaly / Q000097:blood; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000911:Antibodies, Monoclonal; D002851:Chromatography, High Pressure Liquid; D003429:Cross Reactions; D005260:Female; D013007:Growth Hormone-Releasing Hormone / Q000031:analogs & derivatives* / Q000097:blood*; D006801:Humans; D007031:Hypothalamus / Q000737:chemistry; D007118:Immunoassay / Q000379:methods*; D008163:Luminescent Measurements; D008297:Male; D008875:Middle Aged; D010187:Pancreatic Hormones / Q000097:blood*; D010446:Peptide Fragments / Q000097:blood*
D000911:Antibodies, Monoclonal; D010187:Pancreatic Hormones; D010446:Peptide Fragments; C036893:somatotropin releasing factor 40; C040786:somatotropin releasing hormone (1-44)amide; D013007:Growth Hormone-Releasing Hormone