A semi-automated enzymatic assay for free glycerol and triglycerides in serum or plasma

Thermogenic and metabolic consequences of thyroid hormone treatment in brown and white adipose tissue

Male rats were treated with triiodothyronine in the drinking water for 12 days. In vitro rates of isoprenaline stimulated lipolysis were significantly greater in brown but not white adipose tissue. Rates of [14C]glucose incorporation into triacylglycerols were significantly reduced in BAT (brown adipose tissue) and WAT (white adipose tissue) under basal and isoprenaline stimulated conditions. In a second experiment, hyperthyroid animals showed impaired weight gain, despite increased food intake during 19 days' treatment. Energy expenditure on days 5 and 12, and BAT core temperature differences (TBAT - TCORE) on day 19, were significantly greater than in control animals. Epididymal white fat pad weight was reduced and interscapular brown fat pad weight increased by triiodothyronine treatment.

Improved spectrophotometric determination of glycerol and its comparison with an enzymatic method

A chemical method for the determination of glycerol was developed and compared to an enzymatic assay for sensitivity and reproducibility. The chemical assay is based on glycerol oxidation to formaldehyde and subsequent reaction with chromotropic acid to yield a colored product. With this method, as little as 5 micrograms of glycerol/ml can be detected. The enzymatic assay is based on enzymatic glycerol phosphorylation followed by glycerol phosphate dehydrogenation by nadide (nicotinamide adenine dinucleotide). The reduced nadide is used to reduce iodonitrotetrazolium violet to its colored formazan product. The enzymatic method can be used to deterine 50 micrograms of glycerol/ml in aqueous samples.