Abstract
Variable quantities of immunoreactive human growth hormone (IR-HGH) in urine have been reported. The nature of this material in urine is not yet identified. In this study, IR-HGH was measured by the double antibody technique on aliquots of 24 hr urines. The mean 24 hr IR-HGH levels on unprocessed urines from acromegalic and hypopituitary subjects were not statistically different from normals. Immunoreactivity after dialysis disappeared in most normal urines; however, the slopes of inhibitory effects persisted and remained parallel to the standard (std) human growth hormone (HGH) curve in acromegalic urine, and in urines collected from intensive care unit (ICU) patients. To further clarify the nature of this detectable material after dialysis, 24 hr urines were dialyzed, shell-frozen, reconstituted, and fractionated on Sephadex-G-100 column. Eluted fractions were measured for IR-HGH. A single sharp peak with a molecular size in the area of labeled HGH, std pituitary HGH, and endogenously circulating HGH was present in the 24 hr urine concentrates of three acromegalic subjects, pooled newborn urine, and an ICU patient. The total IR-HGH/24 hrs from an isolated HGH-deficient subject was 46.2 ng and the range for acromegalics tested was 72-492 ng. ICU patients in general demonstrated much higher levels. This study demonstrates that the amount of IR-HGH present in urine of normal people is negligible, but that measurable intact IR-HGH is present in urines of active acromegalic subjects, newborns, and in acutely ill patients.
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