Absorption of protamine-insulin in diabetic patients. I. Preparation and characterization of protamine-125I-insulin.
Protamine-125I-insulin with low specific radioactivity was prepared using 125, 127I-insulin, 0.2 I/mole. The preparations were characterized by disc electrophoresis, isoelectric focusing and analytical gel chromatography in order to evaluate the suitability of 125I-insulin as marker for insulin in protamine-insulin. The stability of the preparations was followed up to 90 days at 4 degrees C. The biological and immunological activity was determined in mice, isolated rat fat cells and by radioimmunoassay. It was concluded that both from a chemical and a biological point of view, the protamine-125I-insulin is a satisfactory preparation that might be used in absorption studies.
D000042:Absorption; D002850:Chromatography, Gel; D003920:Diabetes Mellitus / Q000378:metabolism*; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D007328:Insulin / Q000032:analysis / Q000276:immunology / Q000378:metabolism*; D007457:Iodine Radioisotopes; D007526:Isoelectric Point; D011479:Protamines; D011849:Radioactive Tracers
D007328:Insulin; D007457:Iodine Radioisotopes; D011479:Protamines; D011849:Radioactive Tracers