The effect of fetal pig size and stage of gestation on tissue fatty acid metabolism and profile.
The fetus requires an adequate supply of fatty acids for optimum growth and development. It has been hypothesized that reduced activity of enzymes of fatty acid metabolism could contribute to inadequate fetal growth. In a porcine model of differential fetal growth we examined heart and liver fatty acid synthase, delta5-desaturase and delta6-desaturase gene expression and measured hepatic fatty acid profile to assess long-chain polyunsaturated fatty acid status. On gestation days 45, 65 and 100 sows were killed and tissues extracted from an average-sized fetus and the smallest fetus from each litter. As early as day 45, considerable hepatic delta5- and delta6-desaturase was detected, and this expression significantly increased as gestation progressed. In contrast, cardiac desaturase expression remained stable with time. Fatty acid synthase expression was greatest at day 65 in the liver, but was not expressed in the heart. Overall, the smallest fetus did not exhibit reduced tissue delta5- or delta6-desaturase expression or compromised polyunsaturated fatty acid status at any stage. In fact, small fetuses expressed more cardiac delta5-desaturase than their average-sized siblings, possibly in response to a stress to the heart. It is clear from this study that fatty acid metabolism changes markedly as gestation progresses, and reduced fatty acid supply does not cause inadequate growth in this porcine model of fetal development.
McNeil
Christopher J
CJ
Rowett Research Institute, Greenburn Road, Bucksburn, Aberdeen AB21 9SB, UK.
Finch
Angela M
AM
Page
Kenneth R
KR
Clarke
Steve D
SD
Ashworth
Cheryl J
CJ
McArdle
Harry J
HJ
D000818:Animals; D000090943:Delta-5 Fatty Acid Desaturase; D004622:Embryo, Mammalian / Q000033:anatomy & histology* / Q000378:metabolism; D047108:Embryonic Development; D044943:Fatty Acid Desaturases / Q000032:analysis; D064429:Fatty Acid Synthases / Q000032:analysis; D005227:Fatty Acids / Q000032:analysis / Q000378:metabolism*; D005260:Female; D005865:Gestational Age; D050602:Linoleoyl-CoA Desaturase; D008099:Liver / Q000201:enzymology; D023421:Models, Animal; D009206:Myocardium / Q000201:enzymology; D011247:Pregnancy; D013552:Swine
D000090943:Delta-5 Fatty Acid Desaturase; D005227:Fatty Acids; D044943:Fatty Acid Desaturases; D050602:Linoleoyl-CoA Desaturase; D064429:Fatty Acid Synthases