Biochemical changes associated with the fatty liver syndrome in cows.

There were significant changes in enzyme activities and concentrations of metabolites in the blood and liver of cows with fatty livers when compared to normal cows. Blood and liver samples were taken from cows at the abattoir immediately after slaughter. The liver was checked for pathological signs and the samples were divided according to the degree of fatty changes. Three groups were studied: controls showing no gross pathological signs, mild fatty infiltration and severe infiltration. In cows with fatty liver, there were significant increases in the serum activities of isocitric dehydrogenase (ICDH), glucose-6-phosphate dehydrogenase (G6PDH), glutamic dehydrogenase (GLDH), lactic dehydrogenase (LDH), malic dehydrogenase (MDH), aspartate aminotransferase (AST), alkaline phosphatase (ALP) and acid phosphatase (ACP). In the fatty liver, the activities of the enzymes, ICDH, G6PDH, LDH, MDH, ALP and malic enzyme (ME) were significantly higher, while sorbitol dehydrogenase (SDH) was significantly lower. While serum total lipid decreased, the opposite was seen in the liver with higher lipid content, mainly due to triglycerides and cholesterol esters. The significant increases in the NADPH generating enzymes ME, ICDH, G6PDH and MDH, which are required for fatty acid synthesis, suggest that the lipids accumulated in the liver are not only of extrahepatic origin, mobilized into the liver, but also arise from increased lipid synthesis in the liver which is induced during the laying down of fat in the liver. Measurement of the serum NADPH generating enzymes may serve as a useful biochemical test specific for fatty liver in cows.

Biochemical changes in liver and blood during liver fattening in rats.

Excessive fat accumulation in the liver is a common metabolic disorder seen in humans and animals. Fatty liver was induced in the rat by feeding the animals with a sucrose rich diet containing 1% orotic acid for 2-3 weeks. In the sera from fatty liver rats there were significant changes in the level of alanine aminotransferase (+ 68.7%), malic dehydrogenase (+ 77.8%), gamma-glutamyl transpeptidase (- 53.4%) and total lipids (+ 26.6%). There were small to no changes in the levels of aspartate aminotransferase, glucose-6-phosphate dehydrogenase, lactic dehydrogenase, aldolase, malic enzyme, 6-phosphogluconic acid dehydrogenase, alkaline phosphatase and albumin. In fatty liver, significant differences were seen in the levels of glucose 6-phosphate dehydrogenase (+ 235%), malic enzyme (+ 170%), gamma-glutamyl transpeptidase (+ 113%), 6-phosphogluconate dehydrogenase (+ 63%), aspartate aminotransferase (+ 35.6%), malic dehydrogenase (+ 38%), lactic dehydrogenase (+ 37%), and alanine aminotransferase (- 23%). Comparison of the non-fatty part with the fatty part of the fatty liver showed larger changes in the non-fatty part of the liver, suggesting that during the fattening process, there is an induction of enzymes in the liver reaching a peak prior to lipid accumulation, declining thereafter during liver fattening. The increase in NADPH-generating lipogenic enzymes suggests that accumulated fat in the liver is at least partially from de-novo increased synthesis in the liver.

Biochemical changes associated with fatty liver in geese.

Studying biochemical changes in the blood and liver of geese during cramming showed significant increases in the liver enzymes: malic dehydrogenase (MDH), lactic dehydrogenase (LDH), aspartate aminotransferase (AST) and malic enzyme (ME), and a decrease in alkaline phosphatase (ALP). No significant changes were seen in the activity of isocitric dehydrogenase (ICDH), and glucose 6 phosphate dehydrogenase (G6PDH). There were significant increases in serum ME, ICDH, LDH, MDH, AST, acid phosphatase (ACP), sorbitol dehydrogenase (SDH), and total lipids and decreases in serum ALP, albumin and the haemocrit. No significant changes were seen in the activity of cholinesterase, glucose, total proteins, globulins and inorganic phosphorus. There were good correlations between liver size and the change of some of the biochemical parameters studied, which may serve as markers for the presence and degree of liver fattening. There were differences between families of gray and white geese and concentrations and activities of the blood constituents paralleled the degree of liver fattening. The possibility of using these parameters as genetic markers is discussed. No correlations were found between the liver and serum biochemical parameters. The effect of transporting the geese from the farm to the slaughter house on the levels of the blood constituents is described.