Bioactivity of human growth hormone in urine from acromegalic patients.
Bioactivity of hGH in urine from five acromegalic patients was determined by Nb2 bioassay and IM-9 receptor modulation assay (RMA). Urine samples were concentrated by immunoadsorbent chromatography, dialysis and lyophilization. The ratio of the bioactivity by Im-9 RMA and the immunoactivity by RIA was between 0.81 and 1.24 (1.01 +/- 0.19, mean +/- SD). The ratio of the bioactivity by Nb2 bioassay and the immunoactivity ranged from 0.45 to 0.60 (1.37 +/- 0.85). Gel chromatography of hGH in urine samples measured by sensitive sandwich enzyme immunoassay showed that more than 97% of hGH activity was the 22K form. Urinary hGH from acromegalic patients was bioactive in Nb2 bioassay and IM-9 RMA and the bioactivity showed a close correlation with the immunoactivity. The major immunoactive form of hGH (22K) seems to correspond to the bioactivity.
Tanaka
T
T
Endocrine Research Laboratory, National Children's Medical Research Center, Tokyo, Japan.
Umezawa
S
S
Yano
H
H
Hibi
I
I
Shishiba
Y
Y
Teramoto
A
A
Ishikawa
E
E
Murakami
Y
Y
D000172:Acromegaly / Q000652:urine*; D000818:Animals; D002851:Chromatography, High Pressure Liquid; D013006:Growth Hormone / Q000652:urine*; D006801:Humans; D007124:Immunoenzyme Techniques; D008223:Lymphoma / Q000473:pathology; D051381:Rats; D014407:Tumor Cells, Cultured
D013006:Growth Hormone