Biochemical evaluation of mitochondrial respiratory chain enzymes in canine skeletal muscle

OBJECTIVE: To perform respiratory chain enzymatic activity assays on canine skeletal muscle biopsy specimens and establish reference range values of skeletal muscle enzyme activities for dogs. SAMPLE POPULATION: Biopsy specimens from the vastus lateralis muscle were obtained from 24 dogs (8 sexually intact males and 14 sexually intact females) ranging from 15 months to 6 years of age. PROCEDURE: Mean values of citrate synthase, cytochrome-c oxidase, succinate dehydrogenase, succinate dehydrogenase-cytochrome-c reductase, nicotinamide adenine dinucleotide (NADH) dehydrogenase, and NADH dehydrogenase-cytochrome-c reductase activities were established by use of 6 standard spectrophotometric assays for respiratory chain enzyme analysis. RESULTS: Compared with published data for skeletal muscle enzyme activities in humans, skeletal muscle enzyme activities in dogs were 2- to 4-fold higher. Additionally, citrate synthase activity, a marker for mitochondrial volume, was positively correlated with age in dogs, suggesting that mitochondrial volume increases with age, although no apparent change in respiratory chain enzymatic activity with an increase in age was found. CONCLUSIONS AND CLINICAL RELEVANCE: Reference range values for skeletal muscle enzyme activities of dogs are needed to accurately interpret results of respiratory chain enzymatic activity assays. During investigation of metabolic myopathies, if skeletal muscle biopsy specimens are evaluated for respiratory chain enzyme kinetics, they should be performed and evaluated in concert with skeletal muscle biopsy specimens from clinically normal animals of the same species.     

Feedlot performance and tissue residues of cattle consuming diets containing aflatoxins

A comparative slaughter feeding trial was conducted using crossbred Hereford-Angus steers. Cottonseed meal known to be contaminated with aflatoxins was fortified with long-grain rice cultures of Aspergillus flavus to produce complete rations that contained 0, 60, 300 and 600 ppb aflatoxin B1 (AFB1). Forty steers, weighing approximately 250 kg were randomly assigned to four equal treatment groups. Animals were housed in individual pens and fed the assigned contaminated ration ad libitum for 155 d. On d 156 all animals were placed on the control ration for 14 d. Animals were weighed and blood samples collected every month for clinical chemistry analysis. Liver, muscle and fat biopsies were collected at 6-wk intervals. These samples were stored in liquid N2 prior to analysis for aflatoxin M1 and B1 content. Separate liver samples were taken for histopathological examination. Aflatoxin was withdrawn from the diet 2 wk prior to slaughter. After 1 wk of withdrawal liver, muscle and fat samples were collected and assayed for AFB1 and aflatoxin M1 (AFM1). Liver samples also were taken for histopathological examination. Growth rates and feed intakes in the 60 and 300 ppb aflatoxin treatments were not significantly different from controls. The 600-ppb treatment group had a decrease in feed intake and rate of gain. Rations containing 60 and 300 ppb of aflatoxin had no significant influence on blood components and enzyme patterns. The 600-ppb treatment caused a slight, but consistent, increase in serum glutamic oxaloacetic transaminase and alkaline phosphatase.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effects of intramuscular meloxicam administration on prostaglandin E2 synthesis in the North American bullfrog (Rana catesbeiana)

Meloxicam is a commonly used nonsteroidal anti-inflammatory drug (NSAID) in veterinary medicine, but its use in amphibians has not been reported in the literature. NSAIDs are known to act by providing anti-inflammatory and analgesic actions by inhibiting the synthesis of prostaglandin E2 (PGE2). The objective of this study was to evaluate whether the intramuscular administration of meloxicam would decrease the circulating serum PGE2 levels in the North American bullfrog (Rana catesbeiana) following tissue trauma induced by a punch biopsy. Eighteen adult North American bullfrogs were randomly assigned to two treatment groups: meloxicam (0.1 mg/kg i.m.) and control (0.9% saline i.m.). Blood was obtained via cardiocentesis immediately prior to administration of the two treatment regimes and serum was frozen. A 4-mm punch biopsy was taken from the right triceps femoris muscle to induce an inflammatory response. Twenty-four hours later, a second blood sample was collected and serum was harvested and frozen. Serum PGE2 concentrations were measured using a commercial PGE2 enzyme assay (EIA) kit. Twenty-four hours following the biopsy, the mean circulating PGE2 levels of animals treated with meloxicam was 57.79 +/- 12.35 pg/ml, which did not differ significantly from animals that were treated with saline (85.63 +/- 17.55 pg/ml, P > or = 0.05). The calculated means of the absolute change between the circulating baseline PGE2 levels and the postinjury circulating PGE2 levels were significantly lower in animals treated with meloxicam (13.11 +/- 17.31 pg/ml) than in control animals treated with saline (46.14 +/- 38.02 pg/ml) (P < or = 0.05). These results suggest that the systemic administration of meloxicam at a dosage of 0.1 mg/kg once daily suppresses circulating serum PGE2 levels postinjury in the North American bullfrog.     

Effect of nickel deficiency on biochemical variables in serum, liver, heart and kidneys of goats.

Nickel deficiency was induced in 2- to 4-year-old goats by feeding 0.1 mg Ni/kg dry matter with a semisynthetic diet. The control group consumed 5.0 mg Ni/kg d.m. Activity of several enzymes (SDH, LDH, HBDH, AST, ALT, ALD, CK, CHE) was determined in the serum, liver, heart and kidneys. Serum urea-N level was also measured and transmission electron microscopic (TEM) examinations were performed. Signs characteristic of nickel deficiency (retarded growth, increased mortality of dam and offspring, parakeratosis of the skin) appeared in the low-nickel group. The activity of SDH and ALD, as well as the level of urea-N was significantly lower in the serum of Ni-deficient animals than in the control. Ni-deficient animals also had significantly lower enzyme activities in the heart (SDH, HBDH, AST, ALT, ALD and CK), liver (SDH and CHE) and kidneys (HBDH and CK). Electron micrographs showed degeneration of cardiac and skeletal muscle in the Ni-deficient animals. Ni deficiency elicited changes primarily in the heart and these resulted in depressed activity of several enzymes.     

Serum enzyme changes in lambs with experimentally induced acute muscular dystrophy

An experiment was performed to study some serum enzyme changes taking place in artificially fed lambs made dystrophic on a skim milk ration supplemented with α-tocopherolextracted cod liver oil. In the course of two to three weeks the lambs showed highly increased serum values of aspartate- and alanine aminotransferase (AspAT = GOT and A1AT = GPT), total lactate dehydrogenase (LDH), and creatine phosphokinase (GPK). The latter enzyme proved to be the most sensitive test of myopathies, with serum values above 1000 times the normal level. A high-grade hyaline skeletal muscle degeneration was confirmed by histology. Myocardial changes were also present.Contrary to expectations, electrophoretic separation of LDH isoenzymes in the serum of the dystrophic lambs did not reflect any increase of the prevalent muscular cathodic thermolabile fraction LDH₅. The use of a so-called LDH heat stability test as an aid in clinical diagnostic work, as previously suggested, therefore does not seem to be valid in this disease. The results are discussed.     

Serum Enzymes in Pregnant Ewes and Their Newborn Lambs on a Vitamin E-Deficient Ration

A two-years experiment has been performed to investigate the effect of a vitamin E-deficient diet to pregnant adult ewes and their newborn lambs. 18 ewes and 28 lambs have been tested with serum enzyme determinations, and the conclusions drawn are based upon the serum enzyme values. Adult pregnant ewes do not develop increased serum enzyme values on a vitamin E-deficient winter diet, unless a supplement of cod liver oil is given. The lambs from ewes given a vitamin E-deficient ration, show a heavy increase of the serum enzyme values after 2 to 4 weeks of age. This seems to be more pronounced in twins than in single lambs. Even with very high serum enzyme values in lambs, clinical symptoms of muscular dystrophy may be scarce, and the enzyme levels may decline without treatment. Turning out to pasture causes a rise in serum enzyme values in lambs during the first 5 days. Within 12 days at pasture the values become almost normal. Histological examination of skeletal muscle tissue from lambs very high in serum enzymes, may show only small pathological changes.     

Sulfamethazine residues in swine: comparison of on-farm monitoring methods

Three sulfamethazine-residue detection methods were used to evaluate samples collected from five swine farms over a 12-month period. All cooperating farms included sulfamethazine in swine diets at various stages of production, for growth promotion or disease control, and followed recommended drug withdrawal periods. Swine finishing ration, swine urine, and swine serum from market-weight animals were tested monthly for the presence of sulfamethazine. Thin-layer chromatograph (TLC) analysis of swine urine was the gold standard by which three other test method-sample combinations were compared. Samples were analyzed for sulfamethazine using TLC (feed), competitive enzyme immunoassay (serum), and agar-diffusion swab test (urine). The relative sensitivities and specificities of sulfamethazine-residue detection for the three combinations were: (1) TLC analysis (27%, 94%); (2) competitive enzyme immunoassay analysis (58%, 59%); (3) agar-diffusion swab test (78%, 12%). None of the three methods tested was individually adequate for on-farm monitoring of sulfonamide residues. Sulfamethazine residues in swine urine were found on 43.3% of the monthly farm visits and in 19.7% of all swine tested.     

大麦替代饲粮中玉米对生长育肥猪生长性能和胴体品质的影响

大麦替代玉米作为主要能量饲料 ,对育肥猪生长性能、胴体、肉质和消化器官影响的研究结果表明 ,大麦替代玉米后 ,育肥猪日增重显著下降 ,而料重比则明显提高 ,加酶后都得到有效改善 ;大麦组猪背最长肌脂肪含量和脂肪碘值分别降低了 30 .44 %(P<0 .0 5 )和 75 .0 7%(P<0 .0 1) ,加酶后只提高了背最长肌中脂肪含量 ;大麦组猪空肠绒毛高度降低了 42 .86 %(P<0 .0 5 ) ,加酶后得到恢复。由此可见 ,大麦不能直接替代玉米作为主要能量饲料 ,需加入特定的酶制剂 ,才能获得良好的经济效益。     

Effects of percutaneous liver biopsy in alpacas and llamas

OBJECTIVE: To determine changes in results of selected serum biochemical tests after a single percutaneous liver biopsy and changes in results of hematologic and selected serum biochemical tests after multiple percutaneous liver biopsies in alpacas and llamas. ANIMALS: 5 llamas and 10 alpacas. PROCEDURE: A single percutaneous liver biopsy was performed in 5 llamas and 6 alpacas. Blood samples were collected before and 1, 2, and 3 days after liver biopsy, and submitted for serum biochemical analysis. In the other 4 alpacas, liver biopsy was performed on day 0 and then weekly for 4 weeks. Blood samples were collected at the time of each biopsy, and CBC and serum biochemical analyses were performed. Attitude and appetite of all animals were evaluated daily. RESULTS: None of the animals developed clinically apparent adverse effects. A mild decrease in sorbitol dehydrogenase activity was detected in animals that underwent a single liver biopsy, and mild decreases in plasma protein and albumin concentrations were detected in animals that underwent multiple biopsies. Other significant changes were not detected. CONCLUSIONS: Results of this study suggest that liver biopsy is safe in healthy llamas and alpacas and that, if necessary, multiple weekly liver biopsies can be performed safely in healthy alpacas.     

Clindamycin for treatment of Toxoplasma polymyositis in a dog

Toxoplasma polymyositis was diagnosed in a dog given repeated injections of glucocorticoids for a skin condition. The dog developed generalized lower motor neuron paralysis, with generalized hyperesthesia, myoglobinuria, and high serum muscle enzyme activities. Diagnosis of toxoplasmosis was confirmed by muscle biopsy and seroconversion. Despite supportive care, the dog's neurologic status deteriorated progressively until parenteral treatment with clindamycin was instituted. The dog made a gradual recovery, with complete return of locomotor function and muscle mass within 2 months.     

Experimental trichinosis in sheep.

Trichinella spiralis spiralis infections were established in sheep by administering infective larvae via gavage or feeding infected musculature. Trichinella spiralis nativa infective larvae had a low infectivity for sheep although light infections may be established in some animals with large infective doses. For the most part, sheep were averse to ingesting musculature mixed in a grain ration unless it was camouflaged with molasses. The heaviest infections usually occurred in the masseter muscle. The fact that sheep are averse to ingesting muscle tissue may reduce the likelihood of trichinosis. Anti-Trichinella antibodies to both T: spiralis spiralis and T. spiralis nativa were produced as demonstrated by the enzyme-linked immunosorbent assay. Seroconversion occurred in several sheep challenged with T. spiralis nativa even though larvae were not recovered from the musculature by pepsin-digestion.     

Reaction of muscles to a stimulating environment--effects on the loin muscle (M. longissimus) of Landrace pigs

The effects of an enriched environment on growth, meat quality, and muscle biological traits were investigated using 64 castrated pigs (age range 7 to 20 weeks). Positive emotional appraisal was induced by a system that acoustically frequently called individuals out of a group (n=32) to a feeding station, where they were rewarded with small portions of feed. The results were compared with traditional fed pigs (Control; n = 32). There was no environmental effect on live weight and lean muscle percentage. However, the stimulating keeping regime reduced the intramuscular fat content of the M. longissimus by 0.2 % and increased the protein content by 0.5 %. Moreover, the drip loss of M. longissimus was 1.1 % lower in the treatment group. The analysis of muscle fibre traits (biopsy samples of M. longissimus) showed a 7 % higher proportion of oxidative muscle fibres in the pigs reared in the enriched environment. This fibre type showed a tendency to increased fibre areas. These findings indicate a higher oxidative capacity of the muscle. However, the activity of the inarker enzyme citrate synthase (CS) was not influenced and the activity of lactate dehydrogenase (LDH) was even increased compared to the control animals.     

The effect of skeletal muscle needle biopsy on blood constituents, muscle glycogen and heart rate of cattle

Muscle samples from Friesian bulls were obtained using the Bergstr?m percutaneous biopsy needle. The samples (100 to 200 mg) were suitable for metabolite and enzymic analyses and histological examination in relation to meat quality. The physiological response to biopsy was assessed by measuring serum free fatty acid and blood glucose concentrations, plasma creatine kinase activity and heart rate. Muscle glycogen concentration was also measured. These parameters were unchanged by the experimental procedure, with the exception of blood glucose and heart rate which showed significant increases. The experimental animals showed no adverse effects after repeated biopsy and it is concluded that the technique is suitable for investigating beef muscle metabolism in vivo, and does not cause an unacceptable degree of stress.     

Toxicologic studies with sheep fed colored magazines and newsprint.

Paper containing colored inks from magazines and newspapers was fed as 23% of their ration to sheep for 175 days. A similar ration containing oat hulls in place of the paper was fed to control animals. The paper-fed animals consumed 29% more feed than the controls but the feed efficiency (kg animal weight gained/kg ration consumed) of the two rations was approximately equivalent. Lead contained in the paper accumulated in animal tissues. Hepatic microsomal mixed function oxidase activity was several fold higher in the paper-fed animals than the controls. Histopathologic examination of liver and kidney using light and electron microscopy revealed no lesions attributable to diet.     

The effect of feeds treated with ionizing irradiation on biochemical indicators of the nutritional value of energy nutrients

The influence of feedstuffs treated with ionizing radiation on the nutrition of dogs was tested in four groups of animals. Two groups were administered for 90 days a ration, the main part of which (VETACAN meat feed mixture and VETAVIT loose feed mixture) was irradiated with radioisotope Co 60 of the intensity of 25 kGy/kg, in other two groups of dogs the nonirradiated ration was used for the same time period. The control groups of dogs were put together for these two diets. The laboratory examination of irradiated feedstuffs confirmed their complete microbiological and mycological intactness. However, the irradiation brought about a significant 35% degradation of essential amino acids with an increase of ammonia nitrogen, destructive changes in the lipid component of feedstuffs and a partial decomposition of the saccharide part of the VETAVIT feed mixture, expressed by the acidity of water extract. The sensory evaluation of irradiated feedstuffs did not show any perceptible alterations. The haematological examination of the blood of animals, which had been administered irradiated feed rations, demonstrated a significant negative influence on the blood picture. The biochemical examination of the blood serum and plasma revealed that total proteins of experimental dogs dropped and the creatinine level was also significantly decreased. Neither was the level of carbohydrate nutrition nor the energy saturation affected by irradiation. The glucose levels in the blood serum of dogs fluctuated within the range of physiological reference values. The growth of free ammoniacal bases of feedstuffs, evoked by ionizing radiation, conditioned obviously the level of actual pH of blood in dogs as determined in this study. The destruction of lipoid fraction in the feedstuffs induced a decrease in the activity of lipophile retinol and thus the biological value of feeds was impaired. The biochemical examination of ALT, AST and ALP enzyme activity did not show any increased activity of parenchyma, in particular of liver cell. A decisive role of the biological quality of feed ration for utilization of some minerals was demonstrated by a significant decrease of the magnesium level in animals administered irradiated feed rations without any biological supplementation. On the contrary, the potassium, calcium and phosphorus levels did not reflect this dietary difference between the groups.     

Porcine malignant hyperthermia: false negatives in the halothane test

Purebred Pietrain pigs presumed (on the basis of pedigree) to be homozygous for malignant hyperthermia (MH) susceptibility were subjected to a 3% halothane challenge test. A few (6%) pigs that should have been MH susceptible on the basis of parental genotype did not develop muscle rigidity in response to repeated halothane tests. Three of these animals were brought into the laboratory, and muscle biopsy specimens were obtained for in vitro analysis. Bundles of intact muscle cells dissected from biopsy specimens were electrically stimulated, and mechanical responses were monitored during exposure to halothane. In all instances, the muscle bundles from the halothane-negative (ie, not sensitive to halothane), but genetically susceptible, pigs gave in vitro responses that were similar of those of halothane-positive MH-susceptible pigs in that tetanic tension was depressed, tetanus relaxation was slowed, and small contractures were produced upon halothane exposure. Thus, the presence of a halothane-sensitive abnormality in the skeletal muscles, in and of itself, is not always sufficient for development of in vivo muscle rigidity during a brief halothane test. Furthermore, when the halothane testing of pigs is conducted by recommended techniques, false negatives still occur in a small percentage of the genetically MH-susceptible animals.     

Polymyositis in two German wirehaired pointer littermates

Two cases of polymyositis in German wirehaired pointer littermates are described. The seven-month-old dogs were presented with a history of acute vomiting, weakness and drooling from the mouth. Examination of the dogs disclosed muscle weakness, dysphagia, megaoesophagus, elevated serum muscle enzyme levels and abnormal electromyographic and muscle biopsy findings. Both dogs were treated with prednisolone and made a complete recovery. The dam, and two littermates, were also examined, but no signs of polymyositis were seen in these.     

Sarcocystis myositis and vitamin E deficiency in a Gypsy Vanner stallion suspected of having equine motor neuron disease

A 3-year-old Gypsy Vanner stallion was presented for evaluation of intermittent recumbency, muscle fasciculations, weakness, low head carriage, shifting of weight between the hindlimbs and an elevated tail head. History, physical examination and serum alpha tocopherol concentrations were suggestive of vitamin E deficiency and equine motor neuron disease (EMND). Sacrocaudalis dorsalis medialis muscle biopsy identified myositis secondary to sarcocystosis. Treatment with alpha tocopherol, ponazuril and sulfadiazine/pyrimethamine resulted in significant improvement in muscle weakness and body condition with resolution of sarcocystosis and inflammation on repeat muscle biopsy. This case illustrates the importance of muscle biopsy in horses with neuromuscular disease as concurrent diseases may be present that require specific treatment for a positive outcome.