Triglyceride accumulation and very low density lipoprotein secretion by rat and goat hepatocytes in vitro

Utilization of [1-14C] oleate by freshly isolated rat and goat hepatocytes was compared. Intracellular [14C] triglyceride accumulation by hepatocytes did not differ between species. At 2 h of incubation, rat hepatocytes secreted approximately 25 times more [14C] triglyceride than goat hepatocytes. Very low density lipoprotein secretion was greatest by hepatocytes incubated in media containing 4:1 oleate:bovine serum albumin. Rat hepatocytes converted three to four times more [1-14C] oleate to 14CO2 and acid-soluble products than goat hepatocytes. Rate of 14CO2 formation by both rat and goat hepatocytes increased as incubation time increased and as rate of cellular triglyceride accumulation decreased. The ratio of 14CO2:[14C] acid-soluble products formed was greater for rat than goat hepatocytes, which indicated rat hepatocytes may oxidize fatty acid more completely. Differences in metabolic rate, based on oxygen consumption, between isolated goat and rat hepatocytes were minor and could not account for marked differences in very low density lipoprotein secretion. Goat hepatocytes did not incorporate detectable quantities of labeled fatty acid into low or high density lipoproteins. Ruminants may be susceptible to fatty liver when the liver takes up large amount of nonesterified fatty acid due to an inability to efficiently export fatty acid as very low density lipoprotein triglyceride.