ROLE OF THE KIDNEY IN THE PRODUCTION OF A LOW-MOLECULAR-WEIGHT GROWTH-FACTOR (MW-LESS-THAN-1000 DA) - EXPERIMENTAL-STUDY IN THE PIG

Small peptide molecules known as low molecular weight growth factor (L MW-GF) have been identified in human serum. They enhance the effect of IGF-I (insulin-like growth factor) on proteoglycan. synthesis. In the present work we investigated the role played by the kidney in the pro duction of LMW-GF; using the pig as an experimental model. Six pigs un derwent bilateral nephrectomy followed 24 h later by orthotopic autotr ansplantation of the kidney. Renal and liver functions were evaluated by measurement of serum creatinine, urea, electrolytes, amino transfer ases (ASAT: ALAT), proteins, and bilirubin. LMW-GF was measured by bio assay using 11-day-old pelvic chick embryo cartilages. We observed tha t LMW-GF quickly disappeared from pig serum after nephrectomy and only reappeared when transplantation was successful. Reappearance of LMW-G F can precede improvement of renal function evaluated by plasma creati nine levels. These data appear to demonstrate that the kidney is invol ved in LMW-GF production.