Effects of bile salts on the radioimmunoassay of hormonal peptides

Journal Article · Sat May 01 04:00:00 EDT 1982 · J. Lab. Clin. Med.; (United States)

OSTI ID:6780917

Lake-Bakaar, G ^[1]; Tovoli, S; Straus, E; Yalow, R S

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1. Veterans Administration Medical Ceuter, Bronx, NY

The effect of bile salts on RIAs of secretin, glucagon, insulin, and gastrin have been studied. Increasing concentrations of the sodium salts of taurocholic, glycochenodeoxycholic, taurochenodeoxycholic, glycocholic, and taurodeoxycholic acids progressively inhibit the binding of /sup 125/I-secretin to specific antibody, resulting in significant lowering of the B/F ratio at concentrations as low as 0.04 mM and almost complete inhibition at concentrations above 2.4 mM. The nonspecific inhibition by taurodeoxycholate results in a B/F vs concentration curve resembling a secretin standard curve.The binding of /sup 125/I-secretin to charcoal is also inhibited by increasing concentrations of bile salts, although this effect is less marked than their effects on the immune reaction. The binding of /sup 125/I-glucagon, /sup 125/I-insulin, and /sup 125/I-gastrin to specific antisera is also inhibited by sodium taurocholate. Insulin binding is least affected. However, gastrin binding is inhibited by sodium taurocholate at a concentration as low as 0.2 mM. The binding of /sup 125/I-insulin and /sup 125/I-gastrin to charcoal is also inhibited by sodium taurocholate. Thus bile salts interfere in the RIA of hormonal peptides by inhibiting both the immune reaction and the binding of labeled antigen to charcoal. These nonspecific effects must therefore be considered in RIA of body fluids containing high concentrations of bile salts. Treatment of plasma samples with anionic-binding resins can eliminate interference caused by high bile salt concentrations. However, these resins will also remove anionic hormonal peptides such as gastrin.

• OSTI ID: 6780917
• Journal Information: J. Lab. Clin. Med.; (United States), Journal Name: J. Lab. Clin. Med.; (United States) Vol. 99:5; ISSN JLCMA
• Country of Publication: United States
• Language: English

Related Subjects

550601* -- Medicine-- Unsealed Radionuclides in Diagnostics
62 RADIOLOGY AND NUCLEAR MEDICINE
BETA DECAY RADIOISOTOPES
BILE
BIOLOGICAL EFFECTS
BIOLOGICAL MATERIALS
BODY FLUIDS
DAYS LIVING RADIOISOTOPES
ELECTRON CAPTURE RADIOISOTOPES
GASTRIN
GLUCAGON
HORMONES
INSULIN
INTERMEDIATE MASS NUCLEI
IODINE 125
IODINE ISOTOPES
ISOTOPE APPLICATIONS
ISOTOPES
LABELLED COMPOUNDS
MATERIALS
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
PEPTIDE HORMONES
PEPTIDES
POLYPEPTIDES
PROTEINS
RADIOASSAY
RADIOIMMUNOASSAY
RADIOISOTOPES
SALTS
SECRETIN
TRACER TECHNIQUES