A specific solid-phase immunoradiometric assay (IRMA),optimized for maximal sensitivity, has been developed for measurement of human growth hormone in urine. One monoclonal antibody was iodinated using modified Ch-T method, another was linked to CNBr activated Sepharose-4B. The assay sensitivity was 125 pg/L: Intra- and inter-assay variation were 3.8%, 5.19% respectively. The dilution test and the recovery test were satisfactory. This assay is not influenced by the changes of following conditions: pH(5.0- 7.4), 0-0.25 mol/L sodium chloride and 0-0.5 mol/L urea. The GH values in the urine of 10 hours at night in healthy young males (n=9), females (n = 9), patients with acromegaly (n = 9), and patients with complete GH deficiency(n = 8) were 0.55 ?0.50 ng, 0.44 ?0.33 ng, 58.07?35.90 ng, and unde-tectable, respectively. In young males and females, the urinary GH values were not significantly different, while in patients with acromegaly, the urinary GH values were significantly different from that in normal adults(P

Using a highly sensitive IRM A which can detect the hGH in urine directly, we measured the nocturnal urinary GH values in 13 normal men, 12 normal women, and 17 patients with acromegaly. The values were 0.58?0.56 ng, 0.52?0.37 ng, and 167.21 278.2 ng respectively. The nocturnal urinary GH secretion was significantly higher in the acromegalic patients than in the normal adulls (P