Myristic acid increases ∆6-desaturase activity in cultured rat hepatocytes

In order to study the effects of saturated fatty acids on ∆6-desaturase activity, rat hepatocytes in primary culture were incubated with lauric (C12:0), myristic (C14:0) or palmitic (C16:0) acids. After optimization, the standard in vitro conditions for the measurement of ∆6desaturase activity were as follows: 60 μmol·L–1 α-linolenic acid (C18:3n-3), reaction time of 20 min and protein content of 0.4 mg. Data showed that cell treatment with 0.5 mmol·L–1 myristic acid during 43 h specifically increased ∆6-desaturase activity. This improvement, reproducible for three substrates of ∆6-desaturase, i.e. oleic acid (C18:1n-9), linoleic acid (C18:2n-6) and α-linoleic acid (C18:3n3) was dose-dependent in the range 0.1–0.5 mmol·L–1 myristic acid concentration. myristic acid / ∆6-desaturase / saturated fatty acids / cultured rat hepatocytes