PubMed Health⌕ Search

Biomedical subjects

S Sankari

Publications and source records attributed to S Sankari.

At least 37 records · Page 2Linked to original sources
PubMed1994

Exercise-induced changes in blood composition of racing reindeer (Rangifer tarandus tarandus L.).

The responses to near-maximal exercise before and after the training and racing season were examined in reindeer. The reindeer were tested when pulling a driver at a speed of 11-12 m/s for 600 m. The lactate responses were higher before than after training. Similarly, the accumulation of uric acid, a breakdown product of ATP, became attenuated after training. The serum concentrations of nonesterified fatty acids decreased or did not change after exercise, although an increase in the glycerol concentration indicates activation of lipolysis. The concentration of alanine increased after both tests, and at rest the concentrations of several amino acids, e.g., glutamine, isoleucine, and tyrosine, were higher and the concentrations of serum protein and urea were lower during spring than at the beginning of the training period. It can be concluded that the carbohydrate metabolism of the reindeer responds to exercise and training similarly to that in other athletic species, but further studies are needed to explain the observed changes in lipid and protein metabolites.

Acclimatization↗
PubMed1992

Blood chemistry of reindeer calves (Rangifer tarandus) during the winter season.

1. Blood characteristics of reindeer calves fed on lichens were studied during the winter. 2. The serum total protein, albumin and globulin concentrations decreased during the winter, obviously partly due to protein deficiency in the diet. 3. High urea levels in autumn and midwinter were possibly reflections of increased stress and/or protein catabolism. 4. Marked lipolysis occurred in late winter, and thus increases were observed in fatty acids, glycerol, triglycerides and acetoacetate concentrations. 5. Serum sorbitol dehydrogenase (SDH) activity increased towards the spring, most probably reflecting changes in the liver. 6. A decrease in serum alkaline phosphatase (AP) activity occurred in midwinter due to cessation of growth. 7. It can be concluded that all the animals were at least in moderate condition throughout the winter and the physiological responses to a negative energy balanced reflected good adaptation.

Adaptation, Physiological↗
PubMed1992

Blood chemistry and endoparasites of the mountain hare (Lepus timidus L.) in high and low density populations.

In order to study the effect of high population density on the condition, blood characteristics and helminth parasitism of mountain hares (Lepus timidus), 12 specimens were shot in December 1982 and 12 more in February 1983 on the west coast of central Finland (group 1, dense population). In addition 14 hares were shot in December 1982 about 100 km from group 1 (group 2, dense population). Group 3 consists of 15 hares from stable, rather low density populations shot in southern Finland during three previous winters. The hares in group 1 were the lightest, had the least fat and were the most seriously infected with Protostrongylus pulmonalis and Trichostrongylus retortaeformis, while those in group 2 were the heaviest and had the highest Ca, Mg, alkaline phosphatase and creatinine values. The group 3 hares had the most fat. The group 1 animals shot in February 1983 had higher Ca, Mg, triglyceride and cholesterol values than those shot in December 1982. It seems that high population density combined with a lack of suitable food leads to poor condition and high endoparasite abundances. The differences in Ca and Mg are probably due to diet. The higher creatinine values in group 2 and in the hares with little or no T. retortaeformis infection may be due to the greater muscle mass.

Adipose Tissue↗
PubMed1990

Utilization of dietary sodium selenite, barley, oats and meat meal selenium by the chick.

The biological availability of selenium (Se) in barley, oats and meat meal as compared to that in sodium selenite was determined by whole blood glutathione peroxidase (GSH-Px) activity and Se concentration depletion-repletion bioassays. One day old White Leghorn chicks, initially of low-Se status, were further depleted for Se by feeding a low-Se casein basal diet (0.03 mg Se/kg diet) adequate in vitamin E for the first two weeks of life. Repletion treatments of Se at graded levels supplemented by the natural sources or sodium selenite were then provided for 4 weeks. A multiple regression equation was calculated to relate the final whole blood GSH-Px activity and Se concentration to the dietary intake of Se. The percent biological availability of Se present in the natural sources was evaluated by slope ratio analyses in comparison to the standard, sodium selenite (100%). The activity of whole blood GSH-Px established a relative bioavailability for barley, oats and meat meal Se of 85, 41 and 25%, respectively (as mu kat/l), and 81, 51 and 17%, respectively (as mu kat/g Hb). The estimated bioavailability of Se in the different natural sources, as measured by blood Se concentration was: barley, 104%; oats, 99% and meat meal, 69% in comparison to that of sodium selenite. Thus, selenite Se was superior to the natural Se sources for the induction of GSH-Px activity. Barley Se appeared to be of higher biological value to chicks than did oats and meat meal Se. Even though meal Se was retained in appreciable amounts in chick blood, it showed the poorest utilization for the synthesis of blood GSH-Px.

Animal Feed↗
PubMed1990

Studies on the role of lipid peroxidation in the acute toxicity of TCDD in rats.

Lipid peroxidation has been shown to be enhanced following exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), but its role in TCDD toxicity is unclear. The present study was undertaken to further elucidate the relations between lipid peroxidation and TCDD lethality. A time course and dose-response experiment in Long-Evans (L-E; LD50 ca. 10 micrograms/kg) and Han/Wistar (H/W; LD50 greater than 3000 micrograms/kg) rats showed that hepatic lipid peroxidation, measured as the amount of thiobarbituric acid-reactive substances (TBA-RS), was induced by TCDD dose-dependently in L-E, but not in H/W rats. Hepatic glutathione peroxidase activity was suppressed in much the same manner in both strains. Lipid peroxidation correlated with body weight loss in L-E rats alone. When 500 micrograms/kg of TCDD was given to L-E rats, lipid peroxidation increased about 3-fold on Day 11 in the liver, while no change was seen in cardiac or renal TBA-RS. The pair-fed controls did not survive the 11-day test period and exhibited gastrointestinal hemorrhages. At 6 days, liver atrophy and elevated (over 2-fold) TBA-RS values were recorded in pair-fed controls but not in their TCDD-treated counterparts. TCDD decreased hepatic glutathione peroxidase activity by almost 50% at 6 days, while pair-feeding was without effect. Liver morphology was different between TCDD-treated and pair-fed rats. Moreover, the livers of TCDD-treated L-E rats contained much higher concentrations of probably peripheral fat-derived fatty acids than did the livers of pair-fed or ad libitum control rats. Restricted feeding over 6 days induced hepatic lipid peroxidation more in H/W than in L-E rats. Endotoxin increased liver TBA levels similarly in both strains having an additive effect with high doses of TCDD in H/W rats. Added as a 0.5% concentration in chow, butylated hydroxyanisole (BHA), but not ethoxyquin, tended to increase survival rate and time in L-E rats exposed to 20 micrograms/kg of TCDD; at 50 micrograms/kg the only survivor was again in the BHA group. However, neither antioxidant had any effect on initial body weight loss. It is concluded that lipid peroxidation mainly arises as a secondary phenomenon in TCDD toxicity, is not the cause of the typical histopathological liver lesion, but may contribute to lethality.

Animals↗
PubMed1989

Inflammation-related changes in cyclic AMP and cyclic GMP in bovine mastitis.

Cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP) concentrations in milk and plasma samples from healthy and mastitic cows were determined by radioimmunoassay and compared with prostaglandins (PGE2, PGF2 alpha and thromboxane B2 [TXB2]), phospholipids and other relevant parameters in milk and blood. The concentrations of cAMP were about five times higher in plasma (p less than 0.01) than in milk, whereas the cGMP concentration in milk was three times higher (p less than 0.01) than that in plasma in both healthy and diseased animals. In mastitic milk, the cAMP and cGMP concentrations were 19% and 65% and in blood plasma 13% and 84% higher respectively than in healthy animals. In milk, cyclic nucleotide concentrations correlated with the markedly elevated cell count and also with the prostaglandin concentration and pH. In blood, cAMP correlated positively with phospholipids and cGMP with reduced glutathione (GSH). These changes are considered to be important in the disease process and, in particular, the increase in cGMP deserves further study.

Animals↗
PubMed1989

Role of plasma fatty acids, prostaglandins and antioxidant balance in bovine mastitis.

Plasma levels of free fatty acids (FFA) were measured in cows with mastitis. FFA levels are known to be elevated in milk of affected cows, and similar increases were now observed in blood plasma. Of the long-chain polyunsaturated fatty acids which serve as precursors for prostaglandins (PGs), leukotrienes (LT) and related eicosanoids, arachidonic acid (C20: 4 omega-6) was elevated by 156 per cent and C20: 3 (consisting of both omega-3 and omega-6) 153 per cent; eicosapentaenoic acid (20: 5 omega-3), not present in the plasma of healthy animals, was detected in blood of mastitic animals. Arachidonic acid correlated positively with the plasma levels of PGs. Total plasma phospholipids were increased as well, and they were positively correlated with the levels of linoleic and arachidonic acids. Changes in FFA levels correlated positively with parameters of inflammation, like bovine serum albumin and serum N-acetyl-beta-D-glucosaminidase, but negatively with the antioxidant status of the animals (vitamin E, glutathione peroxidase). As PGs and LTs are mediators of inflammation, and products of lipid peroxidation, the increase of plasma FFA could be related to tissue damage caused by oxygen free radicals. Similar processes are, however, involved also in host defence, e.g. in oxidative killing of pathogens.

Acetylglucosaminidase↗
PubMed1987

Milk and blood levels of silicon and selenium status in bovine mastitis.

Milk and blood levels of silicon, selenium and the selenoenzyme glutathione peroxidase (GSH-Px) were measured in 20 healthy and 21 mastitic cows. In milk samples from healthy quarters the mean silicon concentration was 0.81 and in affected ones 0.39 ppm. In serum the mean silicon values were 1.63 and 1.02 ppm respectively. The selenium status was not altered but the level of erythrocyte GSH-Px was lowered in mastitic animals. Silicon is known to have marked effects on free radical formation, lipid peroxidation and macrophage activity. Its possible role in infection and inflammation is evaluated. Some of the functions of silicon may resemble those of selenium. The possibility of lowered levels of silicon and of the selenoenzyme in mastitis calls for experimentation with dietary or pharmaceutical supplementation of these trace elements.

Animals↗
PubMed1987

Effect of Se status on some haematological parameters in neonatal piglets.

Blood samples were taken from 74 1-3 day old piglets, the offspring of sows maintained during pregnancy on a commercial ration with 0.1 ppm of added Se as sodium selenite. At the time of blood sampling, all piglets were treated subcutaneously with 200 mg Fe+3 from iron dextran. Additional blood samples were taken 14 days after the iron treatment. Piglets with 14 day whole blood Se concentrations greater than 74.0 micrograms/l (n = 43) had significantly higher mean numbers of red blood cells than those with whole blood Se less than or equal to 74.0 micrograms/l (p = 0.016). The mean increase in erythrocyte numbers during the 14 day period was significantly higher in the higher than in the lower Se group (p = 0.007) as also in the piglets with plasma GSH-Px activity greater than 799 U/l at 1-3 days of age when compared to the piglets with the GSH-Px activity less than or equal to 799 U/l (p = 0.017).

Animals↗
PubMed1987

Possible roles of vitamin E and glutathione metabolism in bovine mastitis.

Plasma and milk levels of vitamin E were determined in mastitic and healthy cows and compared with erythrocyte GSH and GSH-peroxidase, selenium, silicon, prostaglandins and parameters commonly used for diagnosing mastitis. In mastitis both the plasma and milk levels of vitamin E were significantly lowered. In the milk vitamin E correlated negatively with electrical conductivity and PGE2. In the blood vitamin E was in a positive correlation with erythrocyte GSH. The role of lipid peroxidation in relation to the inflammatory and immunological reactions of mastitis is discussed.

Animals↗
PubMed1986

Somatic cell count and milk yield in relation to haemoglobin concentration in Finnish dairy goats.

Using 400 Finnish goats, the relationship between haemoglobin concentration and somatic cell counts and milk yield was studied. On the basis of haemoglobin concentration the goats were divided into two groups (greater than or less than 5.6 mmol .l-1). Goats with high haemoglobin concentrations had a markedly higher milk yield and the milk had a lower somatic cell count. In contrast, goats with low haemoglobin concentration (less than 5.6 mmol . l-1) had lower milk yields but higher cell counts. The results showed a negative correlation between the cell counts and the haemoglobin concentration.

Animal Husbandry↗
PubMed1986

Prostaglandins and glutathione peroxidase in bovine mastitis.

Prostaglandin (PG) levels in milk and plasma samples from mastitic cows were determined by radioimmunoassay and compared with erythrocyte glutathione peroxidase (GSH-Px) and other relevant parameters in milk and blood. The overall levels of PGE2, PGF2 alpha and thromboxane B2 (TXB2) in milk were two to four times higher than in blood plasma both in healthy and diseased animals (P less than 0.01). In mastitic milk the PG levels were 24 to 55 per cent and in blood plasma 41 to 95 per cent higher than in healthy animals. The changes were significant and largest for the PGF2 alpha values. In milk, the PG concentrations correlated with the markedly elevated cell count (r = 0.49 to 0.57), and TXB2 values also correlated with milk yield. In blood, PGE2 and PGF2 alpha correlated positively with serum albumin, and PGE2 also correlated with glutathione (GSH). PGE2 and PGF2 alpha correlated negatively with GSH-Px and gamma-glutamyl transferase. The substantial decline in GSH-Px in mastitic animals (P less than 0.01) may be related to changes in lipid peroxidation and PG formation. The possible implications of these findings in the treatment of mastitis are discussed.

Animals↗