Selenium supplementation of grazing sheep. III. Effects of supplementation of ewes before and/or after lambing on the selenium status, blood enzyme activities and the growth of their lambs

1980 ◽  
Vol 31 (5) ◽  
pp. 1017 ◽  
Author(s):  
DW Peter
Keyword(s):  
Glutathione Peroxidase ◽  
New England ◽  
Enzyme Activities ◽  
Selenium Supplementation ◽  
Selenium Status ◽  
Selenium Treatment ◽  
Grazing Sheep ◽  
Low Selenium ◽  
Selenium Supplements ◽  
Lamb Growth

The effects of oral selenium administration to ewes during pregnancy and/or following parturition on ewe fertility, the selenium status of the ewes until lambing and of their lambs from birth to 70 days of age, on plasma enzyme activities and on lamb growth were investigated by using four groups of ewes grazing pasture in the low selenium region of New England. Selenium treatment prior to parturition resulted in significantly higher activities of erythrocyte glutathione peroxidase, i.e. a higher selenium status, of both the ewes and their lambs at lambing, though the selenium status of untreated ewes and their lambs was considered adequate. There were significant increases in the activities of erythrocyte glutathione peroxidase of lambs following selenium supplementation of their dams at parturition, whereas activities of lambs with untreated dams declined; depending on the selenium status of the dam, lambs received varying selenium supplements via milk. There were no significant effects of selenium treatment on ewe fertility or on the patterns of growth of the groups of lambs. However, from 49 days of age onwards, lambs whose dams received selenium at parturition were significantly heavier than lambs whose dams did not receive supplementary selenium. The results are discussed in relation to recommended schedules for oral selenium supplementation and the diagnosis of selenium inadequacy in grazing sheep.

Selenium supplementation of grazing sheep. I. Effects of selenium drenching and other factors on plasma and erythrocyte glutathione peroxidase activities and blood selenium concentrations of lambs and ewes

1980 ◽  
Vol 31 (5) ◽  
pp. 991 ◽  
Author(s):  
DW Peter ◽  
PG Board ◽  
MJ Palmer
Keyword(s):  
Glutathione Peroxidase ◽  
New England ◽  
Whole Blood ◽  
Selenium Supplementation ◽  
Selenium Status ◽  
Blood Concentrations ◽  
South Wales ◽  
Grazing Area ◽  
Grazing Sheep ◽  
Low Selenium

Lambs or ewes grazing pastures in the low selenium region of New England in New South Wales were used to study the effects of selenium supplementation on blood and plasma levels of selenium and glutathione peroxidase (GSH-px), and to assess the possibility of using GSH-px activity as an indicator of selenium availability or selenium status in grazing sheep. When lambs were drenched with selenium at 14 days of age there were large and rapid increases in the initially low levels of plasma and erythrocyte GSH-px. The increase in plasma GSH-px was transitory, and a second selenium drench administered to half the treated lambs at 42 days did not evoke any further increase. Erythrocyte GSH-px activities of treated lambs remained elevated for a longer period than plasma GSH-px, and the second selenium drench extended the period of elevation. Alterations in plasma GSH-px of adult ewes drenched with selenium were similar to those observed in the lambs, but erythrocyte GSH-px activities increased much more slowly. The changes in plasma and erythrocyte GSH-px were accompanied by significant alterations in plasma and whole blood concentrations of selenium. Increases in whole blood selenium, because of the plasma component, were much more rapid than those in erythrocyte GSH-px. Transfer of ewes to a new grazing area with a different soil and pasture type led to similar changes in plasma and erythrocyte GSH-px to those produced by selenium drenching. Small increases with time were also observed in the erythrocyte GSH-px activity of untreated ewes grazing the same pasture continuously. These changes were presumably the result of changes in the selenium content and/or availability in the pasture. It was concluded that regular estimations of erythrocyte or whole blood GSH-px activities could be used as an indication of selenium availability and the selenium status of grazing sheep. Changes in pasture and/or grazing area, and the fact that erythrocyte GSH-px activity of adult animals does not immediately attain a new equilibrium value when selenium intake alters must however be taken into account.

Selenium supplementation of grazing sheep. II. Responses in plasma and erythrocyte activities of lambs and adult wethers

1980 ◽  
Vol 31 (5) ◽  
pp. 1005 ◽  
Author(s):  
DW Peter
Keyword(s):  
New England ◽  
Selenium Status ◽  
Plasma Enzymes ◽  
South Wales ◽  
Normal Ranges ◽  
Before And After ◽  
Selenium Treatment ◽  
Content Availability ◽  
Low Selenium ◽  
Made In

The possibility that apparently healthy lambs in the low selenium region of New England in New South Wales may suffer from subclinical nutritional muscular dystrophy (NMD) was investigated. Further studies of the response in plasma activities of the seleno-enzyme, glutathione peroxidase (GSH-px), to selenium drenching were also included. Changes in the GSH-px and glutathione reductase (GR) activities of erythrocytes and plasma and in the activities of several other plasma enzymes were monitored before and after selenium treatment, by oral drench, of lambs and adult wethers maintained in the field. Similar enzyme measurements were made in adult wethers brought indoors and given a pelleted lucerne ration containing adequate selenium. Selenium treatment caused a large, rapid but transient increase in the initially low plasma GSH-px activities of the lambs. With the exception of one animal, similar changes did not occur in the wethers drenched with selenium. However, in the 14 days prior to treatment the GSH-px activities of all wethers increased and on the day of treatment activities were substantially higher than those of the lambs; increases continued in both grazing and pen-fed wethers irrespective of treatment. The selenium content/availability of the pasture grazed by the wethers was apparently higher than that grazed by the lambs and their dams and the main flock from which the wethers were selected. Plasma activities of glutamic oxalacetic transaminase, creatine phosphokinase and sorbitol dehydrogenase of both lambs and wethers fell within normal ranges at all times. These activities indicated that the lambs, despite a low selenium status prior to treatment, were not suffering from subclinical NMD and that the rapid increase in their plasma GSH-px activity following selenium treatment was not due to acute selenium toxicity and tissue damage. The response in plasma GSH-px activity appeared to depend upon the selenium status of animals at the time when selenium was administered.

Glutathione peroxidase and selenium in sheep. I. Effect of intraruminal selenium pellets on tissue glutathione peroxidase activities

1979 ◽  
Vol 30 (4) ◽  
pp. 695 ◽  
Author(s):  
DI Paynter
Keyword(s):  
Glutathione Peroxidase ◽  
Enzyme Activities ◽  
Maximum Activity ◽  
Elemental Selenium ◽  
Selenium Status ◽  
Biological Availability

Two groups of sheep, both on a diet deficient in selenium, were either treated with intraruminal selenium pellets (containing 5% elemental selenium, 95% iron) or remained as untreated controls. At 23 weeks after pellet administration, activities of the selenium-containing enzyme glutathione peroxidase were greatly increased in many of the tissues of treated animals compared with the untreated controls. Maximum activity of erythrocyte glutathione peroxidase was reached 20 weeks after pellet administration. The maximum activity was considerably greater than the activity at which selenium-responsive diseases, in particular selenium-responsive unthriftiness, occur. This, together with the greatly increased enzyme activities in other tissues several months after pellet administration, suggests that selenium status can be adequately maintained for long periods by treatment with these pellets. In contrast to monogastric species, it appears that in the ruminant the biological availability of elemental selenium released from pellets, as determined by tissue glutathione peroxidase activities, is similar to that reported previously for selenite.

Selenium and glutathione peroxidase activity in mountain goats

1985 ◽  
Vol 63 (7) ◽  
pp. 1544-1547 ◽  
Author(s):  
Charles T. Robbins ◽  
Steven M. Parish ◽  
Barbara L. Robbins
Keyword(s):  
Glutathione Peroxidase ◽  
Linear Function ◽  
Peroxidase Activity ◽  
Selenium Deficiency ◽  
Selenium Supplementation ◽  
Glutathione Peroxidase Activity ◽  
Oreamnos Americanus ◽  
Domestic Species ◽  
Mountain Goats ◽  
Low Selenium

Blood glutathione peroxidase (GSH-Px) activity in mountain goats (Oreamnos americanus) is a linear function of blood selenium. GSH-Px activity per unit of selenium (Se) in mountain goats is approximately double that published for the domestic cow and horse. It is hypothesized that high GSH-Px activity per unit selenium in mountain goats reduces their dietary selenium requirement relative to the above domestic species and is an essential adaptation for occupying low-selenium environments. GSH-Px activity peaked 20–30 days after injections of 0.1 and 0.3 mg Se/kg. A higher dose of 0.5 mg Se/kg delayed and decreased the development of peak GSH-Px activity relative to the two lower injection groups. When acute pathology owing to a selenium deficiency is demonstrated in wildlife capture programs, passive selenium supplementation, such as with selenium-containing salt blocks, should begin weeks to months before capture to provide adequate time for GSH-Px development.

Glutathione peroxidase and selenium in sheep. II.* The relationship between glutathione peroxidase and selenium-responsive unthriftiness in Merino lambs

1979 ◽  
Vol 30 (4) ◽  
pp. 703 ◽  
Author(s):  
DI Paynter ◽  
JW Anderson ◽  
JW McDonald
Keyword(s):  
Body Weight ◽  
Weight Gain ◽  
Glutathione Peroxidase ◽  
Peroxidase Activity ◽  
Body Weight Gain ◽  
Selenium Status ◽  
Glutathione Peroxidase Activity ◽  
Central Victoria ◽  
Selenium Treatment ◽  
The Relationship

Low erythrocyte activities of the selenium-containing enzyme glutathione peroxidase were found in Merino lambs in an area of the Strathbogie Ranges in central Victoria where selenium-responsive conditions have previously been reported. Body weight gain trials conducted over 10 properties in the above area demonstrated that the severity of selenium-responsive unthriftiness was significantly correlated with the erythrocyte glutathione peroxidase activity (r = – 0.95, P <: 0.001). Positive body weight responses to selenium treatment were only observed in lambs with erythrocyte glutathione peroxidase activities less than 30 U/g Hb prior to selenium treatment. These findings indicate that measurement of erythrocyte glutathione peroxidase activity provides a convenient index of the selenium status in sheep. ________________ *Part I, Aust. J. Agric. Res., 30: 695 (1979).

Low Selenium Status in the Elderly Influences Thyroid Hormones

1995 ◽  
Vol 89 (6) ◽  
pp. 637-642 ◽  
Author(s):  
Oliviero Olivieri ◽  
Domenico Girelli ◽  
Margherita Azzini ◽  
Anna Maria Stanzial ◽  
Carla Russo ◽  
...  
Keyword(s):  
Glutathione Peroxidase ◽  
Thyroid Hormones ◽  
Peroxidase Activity ◽  
Controlled Trial ◽  
The Elderly ◽  
Serum Selenium ◽  
Selenium Status ◽  
Glutathione Peroxidase Activity ◽  
Double Blind ◽  
Double Blind Placebo

1. Iodothyronine 5′-deiodinase, which is mainly responsible for peripheral triiodothyronine (T3) production, has recently been demonstrated to be a selenium-containing enzyme. In the elderly, reduced peripheral conversion of thyroxine (T4) to T3 and overt hypothyroidism are frequently observed. 2. We measured serum selenium and erythrocyte glutathione peroxidase (as indices of selenium status), thyroid hormones and thyroid-stimulating hormone in 109 healthy euthyroid subjects (52 women, 57 men), carefully selected to exclude abnormally low thyroid hormone levels induced by acute or chronic diseases or calorie restriction. The subjects were subdivided into three age groups. To avoid conditions of undernutrition or malnutrition, dietary records were obtained for a sample of 24 subjects, randomly selected and representative of the whole population for age and sex. 3. In order to properly assess the influence of selenium status on iodothyronine 5′-deiodinase type I activity, a double-blind placebo-controlled trial was also carried out on 36 elderly subjects, resident at a privately owned nursing home. 4. In the free-living population, a progressive reduction of the T3/T4 ratio (due to increased T4 levels) and of selenium and erythrocyte glutathione peroxidase activity was observed with advancing age. A highly significant linear correlation between T4, T3/T4 and selenium was observed in the population as a whole (for T4, R = −0.312, P < 0.002; for T3/T4 ratio, R = 0.32, P < 0.01) and in older subjects (for T4, R = −0.40, P < 0.05; for T3/T4 ratio, R = 0.54, P < 0.002). 5. The main result of the double-blind placebo-controlled trial was a significant improvement of selenium indices and a decrease in the T4 level in selenium-treated subjects; serum selenium, erythrocyte glutathione peroxidase activity and thyroid hormones did not change in placebo-treated subjects. 6. We concluded that selenium status influences thyroid hormones in the elderly, mainly modulating T4 levels.

scholarly journals Selenium deficiency and HIV infection

2010 ◽  
Vol 2 (2) ◽  
pp. 18 ◽  
Author(s):  
Stefano Di Bella ◽  
Elisabetta Grilli ◽  
Maria Adriana Cataldo ◽  
Nicola Petrosillo
Keyword(s):  
Hiv Infection ◽  
Disease Progression ◽  
Selenium Deficiency ◽  
Selenium Supplementation ◽  
Economic Resources ◽  
Common Finding ◽  
Hiv Viral Load ◽  
Conflicting Evidence ◽  
Low Selenium

Selenium is a non-metallic chemical element of great important to human health. Low selenium levels in humans are associated with several pathological conditions and are a common finding in HIV infected individuals. We conducted a review of the literature to assess if selenium deficiency or selenium supplementation could play a role in modifying the clinical course of HIV disease. Several studies investigated the role of selenium in disease progression, morbidity and mortality in HIV infected individuals. Larger studies were conducted in countries with poor economic resources and limited access to HAART. According to the majority of published studies low selenium levels appear to have an association with mortality, and selenium supplementation appears to play a beneficial role on survival or on slowing disease progression among HIV infected individuals. The role of selenium supplementation on preventing hospital admission among HIV outpatients was also noticed. The literature suggests an association between selenium deficiency and development of HIV associated cardiomyopathy and furthermore, selenium supplementation appears to improve the cardiac function in HIV infected individuals with cardiomyopathy. However, there is conflicting evidence regarding the role selenium in modifying HIV viral load and immune status in HIV infection.

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