Effects of low dose of recombinant human growth hormone on renal excretion of insulin-like growth factor-I (IGF-I) in humans: an inverse relation between serum and urinary IGF-I level.
To elucidate the possible physiological interaction between growth hormone (GH) and insulin-like growth factor-I (IGF-I) system in human kidney, recombinant human GH (rhGH), which reached a supranormal level of serum GH, was administered, and serum and urinary IGF-I levels were determined in 6 normal men. The first two days served as a pre-control period (preTx). At days 3 and 4 (Tx), 2 U of rhGH was subcutaneously injected twice at 8:00 AM and 8:00 PM. The following three days (days 5, 6, 7) served as a post-control period (postTx). After rhGH administration, serum level of GH increased rapidly, followed by elevation of serum IGF-I concentration. Changes in creatinine clearance during the study were not significant. The 24-hour urinary IGF-I output decreased significantly during the rhGH administration period compared with that in pre- and post-Tx. During the Tx, urine volume and urinary excretion of electrolytes decreased compared with those in preTx, and mostly returned to the preTx level during postTx. These results indicated an inverse relationship between serum and urinary IGF-I level during the supranormal elevation of serum GH, suggesting IGF-I accumulation within the kidney.
Uemasu
J
J
Second Department of Internal Medicine, Tottori University School of Medicine, Yonago, Japan.
Fujihara
M
M
Kawasaki
H
H
D000328:Adult; D001806:Blood Urea Nitrogen; D004305:Dose-Response Relationship, Drug; D005500:Follow-Up Studies; D019382:Human Growth Hormone / Q000008:administration & dosage*; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000378:metabolism / Q000652:urine*; D007668:Kidney / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D011863:Radioimmunoassay; D011994:Recombinant Proteins; D012016:Reference Values
D011994:Recombinant Proteins; D019382:Human Growth Hormone; D007334:Insulin-Like Growth Factor I