BACKGROUND: Homocysteine (Hcy) is a sulfur-containing amino acid derived from methionine. Several studies have suggested that plasma Hcy may be a useful biomarker of cardiovascular disease in human. There is limited information about serum homocysteine in heart diseases of dogs.OBJECTIVES: The present study aimed to assess the concentration of serum total Hcy and evaluate the relationship between its concentrations and serum levels of cholesterol, triglycerides, and activities of creatine phosphokinase and aspartate aminotransferase in small breed of dogs with endocardiosis.METHODS: For this purpose, a total of 15 dogs (seven males and eight females) with acquired endocardiosis were confirmed by clinical examination, auscultation, thoracic radiography, and echocardiography. In addition, 15 normal dogs of the similar age, breed, and weight were selected as the controls. All the examinations performed on the patients were carried out on the healthy dogs. Homocysteine was measured via an enzymatic method. Additionally, the activities of CPK and AST and the levels of cholesterol and triglycerides were assessed utiling commercial kits. Subsequently, the data were analyzed with t- student test and one- way ANOVA and Pearson’s linear correlation test was used to determine the relationship between serum homocysteine levels with triglycerides, cholesterol, CPK, and AST.RESULTS: The results revealed no significant differences concerning serum homocysteine level and AST activity between the two groups; meanwhile, the increase in serum triglycerides and CPK activities in dogs with heart disease was statistically significant compared to that in the control group. However, there was no significant correlation between homocysteine and the other measured parameters.CONCLUSIONS: The present study indicated that the role of homocysteine as a new risk factor associated with dog endocardiosis is questionable and it seems as if in human studies related to homocysteine and heart disease, the selection of dog as animal model requires further investigation.

Epidemiologic relations were evaluated between plasma concentrations of nutrients and cardiovascular diseases. A total of 220 cats were assessed: 144 cats with noninduced acquired heart disease and 76 clinically normal cats. Plasma was assayed for taurine, alpha-tocopherol, selenium, retinol, and total cholesterol and triglycerides concentrations. Cardiovascular disease groups included dilated cardiomyopathy (n = 53), left ventricular hypertrophy (n = 28), hyperthyroidism (n = 11), and uncertain classification (n = 52). In cats with dilated cardiomyopathy, mean plasma taurine concentration was the lowest of that in cats of any group, being only 38% of the value in healthy cats; females had less than half the mean value of males. Tocopherol concentration was 20% lower than normal, and retinol concentration was 40% higher than normal. Total cholesterol concentration was 36% lower than normal. Triglycerides concentration was higher in these cats than in any other group-twice the value recorded in healthy cats and 67% higher than that in hyperthyroid cats. In cats with hypertrophic cardiomyopathy, almost 15% had mean plasma taurine concentration < 30 micromol/L. Retinol concentration was 15% higher, and triglycerides concentration was 54% higher than normal. Approximately 27% of hyperthyroid cats had mildly decreased plasma taurine concentration. Hyperthyroid cats had the lowest tocopherol and cholesterol values; both were at least 30% lower than normal. Retinol concentration was 30% higher than Approximately 14% of cats with uncertain classification had mildly decreased plasma taurine concentration. Plasma retinol and triglycerides concentrations were higher than normal in 25 and 38% of these cats, respectively. Plasma selenium concentration, compared between healthy cats and cats with cardiac disease, was not significantly different. This observation may not be meaningful, however, in light of the limited number of cats in which selenium was assessed.

This study investigated the existence of difference of fat deposition and lipid metabolism in horses with different races and skills that were used for the same kind of sport. 20 Purebred Arabian and 20 Thoroughbred horses trained for flat race were evaluated. The analyses performed were body condition score, weight and blood collected for determination of triglycerides, total cholesterol and non-esterified fatty acids. Ultrasonography of the thickness of the subcutaneous fat layer was performed on the Longissimus dorsi muscle between the 17th and 18th rib, the thickness of the subcutaneous fat layer on the Gluteus medius muscle using the acetabulum as reference, and the cross section of the same muscle. Race-trained Arabian horses showed greater fat layer deposition in the Gluteus medius and Longissimus dorsei musclesthan Thoroughbred horses. These facts indicate that there is a metabolic difference, besides the phenotype, between the races. They also indicate the need to study specific physical conditioning programs for each kind of race.

Ethionine, an analogue of methionine, induces fatty liver in rats by inhibiting protein synthesis, including that of apolipoproteins in liver. Ethionine was administered to cows to elucidate the participation in fatty liver development of impaired triglyceride secretion from liver attributable to decreased apolipoprotein synthesis. The administration resulted in a significant increase of liver triglyceride contents. Several apolipoproteins were found to have decreased concentrations. In particular, apolipoprotein B-100 in very low-density (0.95 to 1.006 g/ml) lipoprotein and in low-density (1.006 to 1.063 g/ml) lipoprotein fractions was greatly reduced. The decreases of apolipoprotein B-100 concentrations in the 2 lipoprotein fractions were at least partly correlated to the decreased triglyceride concentrations in the respective fractions. Decreased concentrations of apolipoprotein A-I in high-density (1.063 to 1.210 g/ml) lipoprotein were also observed, although not as distinctly as with apolipoprotein B-100. Total cholesterol and phospholipid concentrations in low- and high-density lipoprotein fractions were decreased. The decrease in cholesterol was attributed to reduced concentrations of cholesteryl esters. It was suggested that the impaired lipid secretion from liver attributable to the decreased apolipoprotein concentrations has a role in ethionine-induced fatty liver of cows.

Serum lipoprotein concentrations, routine serum biochemical values, and morphologic changes of the liver were evaluated in cats undergoing weight loss. Food was withheld from 6 obese and 6 control cats for 3 days (days 0 to 2), followed by feeding 50% of previous food intake for 26 days (days 3 to 28). Percutaneous liver biopsy specimens were obtained from all cats on days 0, 7, 14, and 28. Blood samples for serum biochemical analysis and lipoprotein profiles were obtained on days 0, 3, 7, 14, and 28. All cats lost weight throughout the study, and none developed signs of chemical illness, including those of idiopathic hepatic lipidosis syndrome. Serum total cholesterol concentrations decreased initially in all cats, but rapidly returned to normal after day 3 in obese cats, suggesting altered cholesterol metabolism during dietary restriction. Low-density lipoprotein concentrations decreased throughout the study in control cats, but were unchanged in obese cats. Examination of liver biopsy specimens from each cat revealed minimal lipid accumulation in all specimens, although some specimens contained hydropic degeneration.

The effects of coliform endotoxin (E) and recombinant ovine tumor necrosis factor a (TNF) were compared with respect to clinical signs of disease and changes in plasma metabolite and pituitary and pancreatic hormone concentrations in calves. In addition, changes in plasma TNF concentration during each challenge exposure were quantitated by use of radioimmunoassay. Healthy Holstein bull calves with mean body weight of 90 kg were each given, in order, on different days, saline solution (5.0 ml, IV, day 1, n = 4), E (type 055:B5, 1.0 microgram/kg of body weight IV, day 2, n = 4) and TNF (5.0 microgram/kg IV, day 9, n = 3). Jugular venous blood samples, rectal temperature reading, and PCV were obtained at hourly intervals before (2 hours) and after challenge exposure. The PCV increased (P < 0.05) after E and TNF administrations for the first 5 hours, then returned to normal in calves given E, but decreased and remained low in calves given TNF through 24 hours. Plasma triglyceride and nonesterified free fatty acids concentrations were increased through 10 hours (P < 0.05) after E administration, whereas triglyceride and nonesterified free fatty acids concentrations were not significantly affected by TNF administration. Increase in blood glucose concentration at 1 hour after administration of E and TNF was followed by prolonged hypoglycemia that lasted through 6 hours. Changes in plasma insulin concentration paralleled the observed changes in glucose concentration, initially increased at 2 hours after E and TNF (P < 0.05) administrations, but then tended to decrease below control values thereafter. Plasma growth hormone and luteinizing hormone concentrations decreased after E and TNF administrations to almost nondetectable values through 4 hours after dosing, returning to normal values by 8 hours. The data indicate similarities in physiologic response of calves to E and TNF and suggest a role for acute production of TNF as a mediator of E responses.

Serum biochemical indicators of liver function were determined in healthy, age-matched foals during the first 270 days of life. Values were compared with those of healthy adult horses and with those determined on the day of birth (< 12 hours old). Serum alkaline phosphatase, gamma-glutamyl transferase, and L-iditol dehydrogenase activities were increased during the first 2 weeks of life. Serum cholesterol, triglyceride, and total and unconjugated bilirubin concentrations peaked during this same period. During the early neonatal period (<12 hours old), globulin concentrations (mainly beta 2 and gamma fractions) were low and albumin/globulin ratios were high. However, individual values for all analytes were varied.

Betamethasone, a fluorinated and synthetic steroid, is a commonly used glucocorticoid. To our knowledge, no available studies exist concerning the hyperlipidemic effect of betamethasone dipropionate (BDP) in rabbits. Therefore, the current study was conducted to highlight the effects of intramuscular injection of BDP on lipid profile in rabbits, investigate the possible mechanism underlying the produced effects and evaluate the possible antihyperlipidemic effect of atorvastatin (ATR) and fenofibrate (FFB). For this purpose, twenty male New Zealand rabbits were classified into control, BDP (0.5 ml/kg B.wt/ IM/day/single dose), BDP+ATR; rabbits were IM injected with BDP, then they were orally given ATR (1.9 mg./kg. B.wt./ once/ day/ month) and group IV (BDP+FFB); rabbits were IM injected with BDP then they were orally given FFB (7.5 mg/kg B.wt/ once/ day/ month). The obtained result revealed that single IM injection of BDP produced a significant elevation in triglycerides, total cholesterol, LDL level with a significant decline in HDL in comparison to control group on the 3rd,7th,14th, 21st, 30th day of the experiment. On the 30th day of the experiment there was an increase in the ALT, AST, MDA, VCAM-1 as well as a significant decrease in TAC. Furthermore, BDP induced a significant increase in HMG-COA reductase gene expression and a significant decrease in lipoprotein lipase gene expression. Oral administration of ATR or FFB concurrently with BDP for a month succeeded in reducing the hyperlipidemia induced by BDP in rabbits.

Haptoglobin (HP), an acute-phase protein, is detected in serum of cows with hepatic lipidosis (fatty liver). To assess the relevance of Hp in fatty liver, induction of Hp was examined, using conditions similar to those involving development of fatty liver in cows. Induction of Hp was achieved by a combination of dexamethasone administration (0.1 mg/kg of body weight) and 2 days' starvation. Haptoglobin appearance in serum was not associated with the increase of alpha 1-acid glycoprotein (a marker for inflammation). This treatment increased serum nonesterified fatty acids concentration and decreased serum triglycerides concentration. Protein kinase C activity was decreased in the cytosolic fractions of liver and mononuclear cells. Reduction of protein kinase C-catalyzed endogenous protein phosphorylation also was observed, particularly in the cytosolic fractions of the tissue and cells. Detection of Hp in serum of cows with fatty liver appears to be explained by the fact that Hp is induced by dexamethasone administration and starvation, which are similar to the condition responsible for fatty liver development. The change of protein kinase C-catalyzed phosphorylation was suggested to be involved in the induction of Hp in cows.

Alterations in serum lipid and lipoprotein concentrations in ponies with experimentally induced liver disease were investigated. Hepatocellular damage was induced, using a nonlethal dose of carbon tetrachloride. In a separate group of ponies, obstructive jaundice was induced by surgical ligation of the common bile duct. Over a 6-day period, blood samples were obtained from ponies after treatment with carbon tetrachloride and for 12 days in ponies subjected to surgery. Serum cholesterol and triglyceride concentrations were unaffected in both groups of ponies, except for significantly (P < 0.01) high triglyceride concentration in ponies of the ligated group during the second postsurgical week. This increase was most likely attributable to anorexia observed during that period. Hyperbilirubinemia was observed early in ponies of the ligated group; most of the bilirubin was of the conjugated type. Using electrophoretic and ultracentrifugal methods, serum lipoprotein alterations were detected only in ponies of the ligated group. Increases of very low-density and low-density hpoprotein cholesterol concentrations and decrease in high-density lipoprotein cholesterol concentration were found. Although no changes were seen in total serum cholesterol concentration, a redistribution of lipoprotein cholesterol was observed in ponies of the ligated group. Similar alterations in lipoprotein distribution have been found in dogs, rats, and human beings with obstructive jaundice and cholestasis. The association between serum lecithin:cholesterol acyl transferase activities and these lipoprotein alterations remains to be elucidated.