The metabolic profiles of selected tissues were analyzed in hatchlings of the Amazonian freshwater turtles Podocnemis expansa, P. unifilis and P. sextuberculata. Metabolic design in these species was judged based on the key enzymes of energy metabolism, with special emphasis on carbohydrate, lipid, amino acid and ketone body metabolism. All species showed a high glycolytic potential in all samp...

In mammals, extended periods of fasting leads to the accumulation of blood ketone bodies including acetoacetate. Here we show that similar to the conversion of leucine to acetoacetate in fasting mammals, starvation conditions induced ketone body-like acetic acid generation from leucine in S. cerevisiae. Whereas wild-type and ras2Δ cells accumulated acetic acid, long-lived tor1Δ and sch9Δ mutant...

The metabolism of fatty acids involves the production of acetyl coenzyme A and its condensation with oxalacetate for complete oxidation in the citric acid cycle. The availability of oxalacetate can determine the extent of metabolism via the Krebs cycle (1). In the presence of a low level of oxalacetate in the liver, fatty acid metabolism should produce an excess of ketone bodies. Previously (2)...

1. The hepatic concentrations of the ketone bodies and of metabolites and activities of enzymes involved in gluconeogenesis were measured in healthy lactating and non-lactating cows 48h after administration of Voren, an ester of dexamethasone, and compared with those found in control animals given saline. Parallel measurements were also made of the blood concentrations of several of the metabol...

1. The effects of burn injury (33 per cent of body surface area) on the activities of key enzymes in the metabolism of glucose, glutamine and ketone bodies in the epithelial cells of the small intestine and the rates of utilization of glucose, glutamine and ketone bodies by isolated enterocytes have been investigated. 2. Burn injury decreased the maximal activities of hexokinase and 6-phosphofr...

Several lines of evidence implicate excess glucagon secretion in the elevated rates of hepatic glucose production (HGP), hyperglycemia, and ketosis characteristic of uncontrolled insulin-deficient diabetes (uDM), but whether hyperglucagonemia is required for hyperglycemia in this setting is unknown. To address this question, adult male Wistar rats received either streptozotocin (STZ) to induce ...

A primary metabolic disorder may be present in the colonic mucosa of patients with ulcerative colitis. Preserving the epithelium in situ, we evaluated the metabolism of the colonic mucosa of control patients and patients with ulcerative colitis and Crohn's disease. Colonic mucosal strips (approximately 500 mg) were incubated with partially 14C-labeled acetate (C2), butyrate (C4), hexanoate (C6)...

The lactating rabbit synthesizes milk triacylglycerol, which contains a high proportion (approx. 65 mo1/100mol) of medium-chain fatty acids, the remainder being long-chain fatty acids (Smith et al., 1968). Experiments in vivo with suckling rabbits had shown that medium-chain milk fatty acids were transported to the liver via the hepatic portal vein, and were taken up by the liver. In order to c...

The objective of the study was to analyse relationships between some metabolites associated with cows energy and(or) protein status, body condition score (BCS) and fertility parameters on two Estonian commercial farms. Farm and(or) stage of gestation and(or) lactation were the factors affecting BCS and urea, cholesterol, triglycerides, glucose, ketone bodies, NEFA and total lipids concentration...

Ketone bodies are the most energy-efficient fuel and yield more ATP per mole of substrate than pyruvate and increase the free energy released from ATP hydrolysis. Elevation of circulating ketones via high-fat, low-carbohydrate diets has been used for the treatment of drug-refractory epilepsy and for neurodegenerative diseases, such as Parkinson's disease. Ketones may also be beneficial for musc...