Effect of dietarypolyunsaturated fatty acidson Stearoyl CoA-Desaturasegene expression inintramuscular lipids of lamb

摘要

The effect of replacement of dietary sunfloweroil (SO) with linseed oil (LO) onStearoyl CoA desaturase (SCD) gene expressionwas investigated. Thirty-six lambs wererandomly assigned to four groups and fed withone of the experimental diets, consisting oflucerne pellets with oil (60 g/Kg). The dietsvaried in the percentage of the oil supplementedand were: 100% SO; 66.6% SO plus 33.3% LO;33.3% SO plus 66.6% LO and 100% LO. The trialperiod was of 7 weeks. Longissimus dorsi wasremoved from each carcass and stored at -80°Cuntil the analysis. Total fatty acids compositionwas determined by gas-chromatograph, whileSCD gene expression was assessed by Real-Time Reverse-Transcription PCR. Replacementof SO with LO decreases significantly the SCDmRNA content with a concomitant incrementof polyunsatured fatty acids (PUFA) n-3. Theseresults are related to the higher level of PUFAn-3 present in linseed than sunflower.Although, there were differences on mRNAlevel, there was not a simultaneously changeson SCD activity. In conclusion, PUFA n-3 act onthe regulation of mRNA SCD level withoutaffecting the activity of the relative enzyme.