Analytical validation and biological evaluation of a high molecular-weight adiponectin ELISA.

Background: Of the 3 circulating multimeric forms of adiponectin, the high-molecular-weight (HMW) form, as measured by size-exclusion and/or immunoblotting techniques, is a better index of insulin sensitivity for monitoring health and disease than is total adiponectin. We aimed to develop a simple ELISA to measure HMW adiponectin.

Methods: We pretreated serum or plasma samples with digestion solution containing proteinase K (Millipore, ESDS).

Development of a novel ELISA for human insulin using monoclonal antibodies produced in serum-free cell culture medium.

Objectives: Development of an ELISA for human insulin that utilizes monoclonal antibodies (mAbs) produced in serum-free medium.

Design And Methods: Insulin mAbs were produced in vitro by hybridomas in serum-free medium. A two-step ELISA was developed to replace bovine insulin (standard) and bovine serum albumin (assay buffer) with non-animal reagents.

Regulation of resistin expression and circulating levels in obesity, diabetes, and fasting.

Resistin was originally reported as an adipose tissue-specific hormone that provided a link between obesity and diabetes. Resistin protein level was elevated in obese mice and decreased by insulin-sensitizing thiazolidinediones. Immunoneutralization of resistin improved insulin sensitivity in diet-induced obese mice, while the administration of exogenous resistin induced insulin resistance.

Differential regulation of adiponectin secretion from cultured human omental and subcutaneous adipocytes: effects of insulin and rosiglitazone.

Adiponectin is an adipocyte-derived plasma protein with insulin-sensitizing and antiatherosclerotic properties. Because adipose tissue depots differ in the strength of their association with the adverse metabolic consequences of obesity, we studied the secretion of adiponectin in vitro from paired samples of isolated human omental and sc adipocytes and its regulation by insulin and rosiglitazone. Cells were incubated for 12 or 24 h with and without treatment with 100 nM insulin, 8 micro M rosiglitazone, or both combined; adiponectin secreted into the culture medium was measured by a RIA with a human adiponectin standard and normalized for cellular DNA content.

Adiponectin is not altered with exercise training despite enhanced insulin action.

Adiponectin is an adipocytokine that is hypothesized to be involved in the regulation of insulin action. The purpose of the present investigation was to determine whether plasma adiponectin is altered in conjunction with enhanced insulin action with exercise training. An insulin sensitivity index (S(I)) and fasting levels of glucose, insulin, and adiponectin were assessed before and after 6 mo of exercise training (4 days/wk for approximately 45 min at 65-80% peak O(2) consumption) with no loss of body mass (PRE, 91.