Effects of Two Different Medium-Chain Triglycerides (Tri C₈:0 and Tri C₁₂:0) on Liver Lipids in the Growing Rat

Abstract

Results presented in this study emphasize the long-term effects of dietary fatty acid chain length on some biochemical parameters of the liver in the growing rat. High levels of medium-chain fatty acids feeding (C8:O and C12:O) from 40 to 340 g of body weight induced liver growth and lipid contents intermediary between values recorded with a lipid-free diet and with a diet containing long-chain fatty acids. No steatosis was recorded but neutral lipid contents appeared to be correlated with the dietary fatty acid chain length while phospholipid contents remained much more stable. In the four tested nutritional conditions, only dodecanoïc or lauric acid (C12:O) feeding induced important alterations in the fatty acid pattern of liver neutral lipids. Medium-chain fatty acids, and even lauric acid which was intensely esterified in adipose tissue triglycerides, did not appreciably modify the fatty acid composition of liver phospholipids and were not esterified in it.

Effects of Maternal Dodecanoic or Laurie Acid (C12:0) Feeding on Milk Fatty Acid Secretion and Lipogenesis in the Suckling Rat

“…This confirms previous data reported for long-term feeding of lauric acid in the adult rat (4,8). The differ ences in fatty acid composition concerned over all LCPFA and must be related more to the different levels of linoleic acid (C l8:2 n-6) in the two milks than to the occurrence of high MCFA levels in group B milk.…”

“…Maternal feeding indirectly influenced these compositions. As previously observed in adults (8), liver neutral lipids (NL) were charac terized by a strong similitude with the body triglycerides in long-chain fatty acid (LCFA) feeding (group A) and showed large differences with MCFA feeding (group B). In this nutri tional condition, lauric acid (C l2:0) concentra tion was 3 times lower than in body triglycer ides.…”

“…This higher rate of lauric acid oxidation could partly explain the differences recorded between the two groups of pups. Long-chain polyunsaturated fatty acid (LCPFA) concentrations in hepatic neutral lipids were high for these types of fatty acids in the two groups; the levels of n-6 (group A) and n-3 (group B) LCPFA in 21-day-old rats were much higher than in adult rats (8). This con firms previous observations reported by Sinclair (19) and Sinclair and Crawford (20), inter preted as a large concentration and incorpora tion of milk LCPFA into liver triglycerides; they may be related to a limit in the amount of LCPFA which can be esterified during phospho lipid biosynthesis in the suckling pup.…”