Comparative rates of free fatty acid esterification in rat epididymal, perirenal and omental adipose tissue

Abstract

1. 1. Investigations were undertaken to measure comparative rates of free fatty acid esterification into triglyceride by rat epididymal, perirenal and omental adipose tissue in vitro. 2. 2. Since recent reports have shown the presence of glycerokinase activity in epididymal adipose tissue, esterification was estimated from the incorporation of [ 14C]palmitic acid from the incubation medium into tissue triglyceride rather than from glycerol release by the tissue. 3. 3. Epididymal tissue contained 6.08 ± 0.46 μequiv free fatty acid/g tissue which was significantly different from the omental tissue level of 3.97 ± 0.24 P < 0.01) and from the perirenal free fatty acid concentration of 4.97 ± 0.22 ( P < 0.05). Omental and perirenal free fatty acid concentrations were significantly different at the 2% level. 4. 4. No difference was observed between the esterification rates in epididymal and omental tissue. There was a significant difference ( P < 0.05) between the rate of esterification in epididymal tissue (2.501 ± μequiv/g per h ± 0.54) and that in perirenal tissue (1.43 μequiv/g per h ± 0.25). Esterification in omental tissue (2.14 μequiv/g per h ± 0.31) was significantly greater than that observed in perirenal tissue ( P < 0.02). 5. 5. It is suggested that tissue morphology and a possible variation in glycero-kinase activity may contribute to the observed differences in esterification rates.