scholarly journals Metabolic studies of [75Se]selenomethionine and [75Se]selenite in the rat

1973 ◽  
Vol 30 (1) ◽  
pp. 139-147 ◽  
Author(s):  
Christine D. Thomson ◽  
R. D. H. Stewart
Keyword(s):  
Oral Administration ◽  
Urinary Excretion ◽  
Tissue Distribution ◽  
Intestinal Absorption ◽  
Initial Period ◽  
Similar Rate ◽  
Whole Body ◽  
Body Retention ◽  
Metabolic Pool

1. Information was sought concerning the long-term fate of orally and intravenously administered [75Se]selenomethionine and [75Se]selenite in rats.2. Urinary and faecal radioactivity was assayed during the 1st week and whole-body radio-activity was determined weekly for 16 weeks. Rats were killed at intervals for analysis of 75Se tissue distribution.3. Intestinal absorption after oral administration was estimated to be 91–93% for selenite and 95–97% for selenomethionine.4. Urinary excretion of absorbed [75Se]selenite was greater than that of [75Se]selenomethionine during the 1st week.5. After the 1st week, whole-body retention diminished exponentially at a similar rate in rats given either selenomethionine or selenite. Except for the erythrocytes, 75Se content of individual tissues also decreased exponentially.6. It appears that, after an initial period, 75Se from either selenomethionine or selenite is metabolized similarly, suggesting that Se from both potential dietary sources is ultimately incorporated into the same metabolic pool.

scholarly journals Metabolic studies of [75Se]selenocystine and [75Se]selenomethionine in the rat

1975 ◽  
Vol 34 (3) ◽  
pp. 501-509 ◽  
Author(s):  
Christine D. Thomson ◽  
Bridget A. Robinson ◽  
R. D. H. Stewart ◽  
Marion F. Robinson
Keyword(s):  
Oral Dose ◽  
Urinary Excretion ◽  
Tissue Distribution ◽  
Similar Rate ◽  
Whole Body ◽  
Rabbit Kidney ◽  
Body Retention ◽  
Metabolic Pool

1. The long-term fate in rats of an oral dose of [75Se]selenocystine was compared with that of an oral dose of [75Se]selenomethionine.2. Urinary and faecal radioactivities were measured during the 1st week and whole-body radioactivity was determined for 10 weeks. Rats were killed at weekly intervals for 4 weeks and at weeks 6 and 10 for analysis of tissue distribution of 75Se.3. Intestinal absorption of [75Se]selenocystine was 81% of the administered dose; that of [75Se]selenomethionine was 86%. Urinary excretion of absorbed [75Se]selenocystine was 13.9% and that of [75Se]selenomethionine was 5.8%, in the 1st week.4. Whole-body retention of 75Se was greater for [75Se]selenomethionine than for [75Se]-selenocystine but after the 1st week it decreased at a similar rate in both groups. Tissue distribution of retained 75Se was also similar in both groups.5. The initial utilization of [75Se]selenocystine was different from that of [75Se]selenomethionine. However, after the 1st week 75Se from both sources appeared to be metabolized similarly, suggesting that dietary Se of both forms is ultimately incorporated into the same metabolic pool.6. When these findings were compared with those of earlier studies with [75Se]selenite and 75Se incorporated in vivo into rabbit kidney (RK-75Se) (Thomson, Stewart & Robinson, 1975) the metabolism of [75Se]selenocystine resembled that of [75Se]selenite and RK-75Se, rather than that of [75Se]selenomethionine.

scholarly journals Metabolic studies in rats of [75Se]selenomethionine and of 75Se incorporated in vivo into rabbit kidney

1975 ◽  
Vol 33 (1) ◽  
pp. 45-54 ◽  
Author(s):  
Christine D. Thomson ◽  
R. D. H Stewart ◽  
Marion F. Robinson
Keyword(s):  
Oral Dose ◽  
Tissue Distribution ◽  
Similar Rate ◽  
Whole Body ◽  
Rabbit Kidney ◽  
Kidney Homogenate ◽  
Body Retention ◽  
Metabolic Pool

1. [75Se]selenomethionine was administered to four rabbits and after 4 d their kidneys were removed and homogenized. The long-term fate in rats of an oral dose of this kidney homogenate (RK-75Se) was compared with that of an oral dose of [75Se]selenomethionine mixed with unlabelled rabbit kidney homogenate.2. Urinary and faecal radioactivities were measured during the 1st week and whole-body radioactivity was determined for 10 weeks. Rats were killed at weekly intervals for 4 weeks for analysis of tissue distribution of 75Se.3. Intestinal absorption of RK-75Se was 87%; that of [75Se]selenomethionine was 91%. Urinary excretion of absorbed RK-75Se was 13·3% and that of [75Se]selenomethionine was 7·6%, in the 1st week.4. Whole-body retention of 75Se was greater for [75Se]selenomethione than for RK-75Se but after the 1st week decreased at a similar rate in both groups. Tissue distribution of retained 75Se was also similar in both groups.5. The initial utilization of 75Se in rabbit kidney is different from that of [75Se]selenomethionine. However, after the 1st week 75Se from these sources appears to be metabolized similarly, suggesting that Se from both is ultimately incorporated into the same metabolic pool.

scholarly journals The metabolism of [75Se]selenomethionine in four women

1976 ◽  
Vol 35 (3) ◽  
pp. 373-382 ◽  
Author(s):  
Nora M. Griffiths ◽  
R. D. H. Stewart ◽  
Marion F. Robinson
Keyword(s):  
Gradual Increase ◽  
Initial Period ◽  
Maximum Level ◽  
Experimental Period ◽  
Whole Body ◽  
Faecal Excretion ◽  
Body Retention ◽  
Level 3 ◽  
Initial Uptake

1. The long-term fate of an oral dose of [75Se]selenomethionine was studied in four women.2. Urinary and faecal excretion, respiratory losses and whole-body retention of 75Se were measured, and also 75Se turnover in whole body, plasma and erythrocytes during a period of 33–44 weeks.3. Intestinal absorption of [75Se]selenomethionine by the four subjects was 95.5–97.3% of the administered dose.4. Urinary excretion accounted for 6–9% of absorbed 75Se in the first 2 weeks. No radioactivity was detected in expired air.5. After the initial 8 weeks during which radioactivity decreased more rapidly, whole-body retention of 75Se decreased exponentially with a half-time of 207–290 d.6. Plasma 75Se concentration reached a maximum level 3–4 h after the dose. Transient initial uptake of 75Se in erythrocytes during the first hour was followed by a gradual increase to a maximum concentration at 8–12 weeks.7. These results are compared with the results of an earlier study of the metabolism of [75Se]selenite in two of the same women. 75Se from [75Se]selenomethionine was found to be more completely absorbed, had a greater retention and smaller endogenous urinary and faecal losses than 75Se from [75Se]selenite, and these differences persisted throughout the experimental period. These findings differed from those obtained in rats in which, after an initial period, 75Se from selenite was metabolized similarly to that from selenomethionine.

Whole-body Retention and Tissue Distribution of 60Co in Rats After Oral Administration of Freshwater Fish Contaminated With 60Co

1982 ◽  
Vol 43 (2) ◽  
pp. 247-250 ◽  
Author(s):  
Jiro Inaba ◽  
Yoshikazu Nishimura ◽  
Ken-Ichi Kimura ◽  
Ryushi Ichikawa
Keyword(s):  
Oral Administration ◽  
Tissue Distribution ◽  
Freshwater Fish ◽  
Whole Body ◽  
Body Retention

scholarly journals Whole-body Retention and Tissue Distribution of Cesium-134 in New-born, Young and Adult Rats

1967 ◽  
Vol 8 (3-4) ◽  
pp. 132-140 ◽  
Author(s):  
Jiro INABA ◽  
Naonori MATSUSAKA ◽  
Ryushi ICHIKAWA
Keyword(s):  
Tissue Distribution ◽  
Whole Body ◽  
Adult Rats ◽  
New Born ◽  
Body Retention

scholarly journals Consequences of prenatal and preweaning growth for yield of beef primal cuts from 30-month-old Piedmontese- and Wagyu-sired cattle

2009 ◽  
Vol 49 (6) ◽  
pp. 468 ◽  
Author(s):  
P. L. Greenwood ◽  
L. M. Cafe ◽  
H. Hearnshaw ◽  
D. W. Hennessy ◽  
S. G. Morris
Keyword(s):  
Growth Rate ◽  
Environmental Factors ◽  
Tissue Distribution ◽  
Early Life ◽  
Low Birthweight ◽  
Carcass Weight ◽  
Whole Body ◽  
Target Market ◽  
Subsequent Growth

Cattle sired by Piedmontese or Wagyu bulls were bred and grown within pasture-based nutritional systems followed by feedlot finishing. Effects of low (mean 28.6 kg, n = 120) and high (38.8 kg, n = 120) birthweight followed by slow (mean 554 g/day, n = 119) or rapid (875 g/day, n = 121) growth to weaning on beef primal cut weights at ~30 months of age were examined. Cattle of low birthweight or grown slowly to weaning had smaller primal cuts at 30 months as a result of reduced liveweight and smaller carcasses compared with their high birthweight or rapidly grown counterparts. Hence they require additional nutritional and economic inputs to reach target market weights. At equivalent carcass weights (380 kg), cattle restricted in growth from birth to weaning yielded slightly more beef and were somewhat leaner than their rapidly grown counterparts, resulting in primal cuts being up to 4% heavier in the slowly grown compared with the rapidly grown cattle. Compositional differences due to birthweight were less apparent at the same carcass weight, although low birthweight cattle had a slightly (~2%) heavier forequarter and slightly lower (~1%) hindquarter retail yield, and less shin-shank meat (~2%) than high birthweight cattle, suggesting only minor effects on carcass tissue distribution. There were few interactions between sire genotype and birthweight or preweaning growth, and interactions between birthweight and preweaning growth were not evident for any variables. However, variability between cohorts in their long-term responses to growth early in life suggests other environmental factors during early-life and/or subsequent growth influenced carcass yield characteristics. Overall, this study shows that effects of birthweight and preweaning growth rate on carcass compositional and yield characteristics were mostly explained by variation in carcass weight and, hence, in whole body growth to 30 months of age.

DIFFERENTIAL ACTION OF PARATHYROID AND THYROID HORMONES ON EFFECTIVE INTESTINAL ABSORPTION OF CALCIUM

1973 ◽  
Vol 73 (3) ◽  
pp. 489-498 ◽  
Author(s):  
R. Hehrmann ◽  
J. Hagemann ◽  
R. Montz ◽  
E. Jentsch
Keyword(s):  
Thyroid Hormones ◽  
Intestinal Absorption ◽  
Calcium Absorption ◽  
Cyclic Adenosine Monophosphate ◽  
Adenosine Monophosphate ◽  
Whole Body ◽  
Effective Absorption ◽  
Body Retention ◽  
Parathyroid Extract

ABSTRACT The effects of parathyroidectomy (PTX) and radio-thyroidectomy (131I-TX) as well as the actions of parathyroid extract (PTE), dibutyryl cyclic adenosine monophosphate (DBcAMP), calcitonin (CT) and thyroid extract (thyreoidea sicca) on effective intestinal calcium absorption in intact, PTX and 131I-TX rats were evaluated by a new, physiological in vivo method. Ten hours after the administration of 47calcium labelled food the animals were killed and the entire intestine was removed. Whole body retention of 47calcium was measured allowing the calculation of the effective intestinal absorption of calcium (true absorption minus excretion within ten hours). The known actions of PTE and DBcAMP were confirmed by this method. CT did not exert a direct effect in any of the experimental groups. The absence of thyroid hormones (TX rats) remarkably reduced effective calcium absorption. In the presence of endogenous parathyroid hormone (PTH) (TX rats) the administration of minimal amounts of thyroid hormones was sufficient to increase effective calcium absorption, whereas PTE and DBcAMP did not have any effect. In the absence of PTH (TX-PTX rats) thyroid hormones did not enhance effective absorption, indicating, that thyroid hormones alone do not stimulate the effective absorption of calcium. It is concluded, that the thyroid hormones act indirectly, as a permissive agent, enabling PTH to exert its active stimulating effect on the effective intestinal absorption of calcium.

The whole body retention and tissue distribution of [203Hg]methylmercury in adult cats

1975 ◽  
Vol 33 (3) ◽  
pp. 438-449 ◽  
Author(s):  
J.G. Hollins ◽  
R.F. Willes ◽  
F.R. Bryce ◽  
S.M. Charbonneau ◽  
I.C. Munro
Keyword(s):  
Tissue Distribution ◽  
Whole Body ◽  
Body Retention ◽  
Adult Cats
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