The effect of medium and long chain triglyceride on human adipose tissue metabolism

Studies have been performed to assess the effects, in vivo and in vitro, of lipid emulsions on human adipose tissue prostaglandin production. Subcutaneous adipose tissue obtained either during elective surgery or by needle aspiration was studied in tissue culture or by using a perifusion apparatus. Physical mixtures of emulsions of long chain triglyceride (LCT) and/or medium chain triglyceride (MCT) were added to the tissue culture medium so that the final concentration was 400 mg/dl. After a 3-day incubation period the tissue was harvested, placed in buffer and used to determine in vitro production of prostaglandin E2, prostacyclin I2 (measured as its stable end product 6-keto PGF1 alpha) and thromboxane A2 (measured as TXB2) by radioimmunoassay. The results demonstrated that samples incubated in 100% MCT had the most significant increase in prostaglandin production, while those incubated in 100% LCT had the most significant decrease in activity of the three prostaglandins assayed. The addition of LCT to MCT caused a stepwise decrease in adipose tissue prostaglandin production. The data suggest a pharmacological rather than a physiological effect of lipid emulsions containing MCT and/or LCT on adipose tissue prostaglandin production. In vivo effects of a 20% safflower oil emulsion, containing high levels of the essential fatty acid linoleate, were assessed in five pediatric patients. Adipose tissue was obtained before and after two and four weeks of treatment. Fatty acid profiles and prostaglandin production were determined. The results demonstrated that intravenous fat infusion increased the concentrations of linoleic and arachidonic acids found in adipose tissue within a short interval.(ABSTRACT TRUNCATED AT 250 WORDS)