A bioassay for NSILA-S in individual serum samples and its relationship to somatotropin.
A practical bioassay for the acid-ethanol soluble non-suppressible insulin-like activity (NSILA-S) of individual serum samples has been developed utilizing the incorporation of 14C-glucose into the lipid faction of isolated adipocytes. NSILA-S activity was correlated with somatotropin status. Thus, the mean potencies (+/-SD) relative to an extract of pooled normal human serum were: normal samples 1.11 +/- 0.14, acromegalic 2.91 +/- 0.72, and somatotropin deficient 0.13 +/- 0.06. This variation in NSILA-S was not due to variability in extraction recoveries. The within assay precision was 9% (coefficient of variation) and the between assay 23%. This method allows the simultaneous extraction and processing of relatively large numbers of samples, and compares favorably with other more complex methods. Because of the evidence that NSILA-S may be related to the somatomedins, the present method should provide a simpler and more reliable alternative to the cartilage bioassays used to measure somatomedin activity.
D000172:Acromegaly / Q000097:blood; D001681:Biological Assay; D013006:Growth Hormone / Q000097:blood*; D006801:Humans; D007018:Hypopituitarism / Q000097:blood; D013002:Somatomedins / Q000032:analysis*
D013006:Growth Hormone; D013002:Somatomedins