CHARACTERIZATION AND PARTIAL-PURIFICATION OF A FACTOR FROM UREMIC HUMAN-SERUM THAT INDUCES INSULIN RESISTANCE
CHARACTERIZATION AND PARTIAL-PURIFICATION OF A FACTOR FROM UREMIC HUMAN-SERUM THAT INDUCES INSULIN RESISTANCE
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DOI:
10.1172/jci111712
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发表时间:
1985-01-01
影响因子:
15.9
通讯作者:
LOCKWOOD, DH
中科院分区:
文献类型:
--
作者:
MCCALEB, ML;IZZO, MS;LOCKWOOD, DH
The incubation of normal rat adipose tissue with sera from nondialyzed, nondiabetic uremic patients reduces the transport and metabolism of glucose, in the absence and presence of insulin. Insulin-stimulated glucose metabolism by normal rat adipocytes was used as a bioassay to identify the resistance activity, assess the effect of chemical modification on it and the clinical states associated with its production. The resistance activity was trypsin-labile and had an apparent isoelectric point between 6 and 7, but was not retained by either protein A or concanavalin A columns. the insulin resistance activity was decreased by coincubation with the protein synthesis inhibitor, cycloheximide. Purification to greater than 200,000-fold was attained by heating (100.degree. C) uremic serum, subjecting the supernatant to Sephadex G-25 chromatography and subsequent adsorption to DEAE at pH 7.8 and elution at pH 6.5. The partially purified resistance activity was retained within dialysis tubing of 1,000-MW cutoff but not within 2000-MW cutoff. Hemodialysis of patients over 1 wk-18 mo reduced significantly the amount of resistance activity in their sera. The resistance activity, present in most uremic patients, was not found in the sera of individuals with normal renal function but who were either obese, fasted, elderly or had type II diabetes mellitus. A circulating small MW peptide, unique to uremia, induced insulin resistance by a protein synthesis-dependent mechanism.