Metabolic studies in rats of 75Se incorporated in vivo into fish muscle

1977 ◽  
Vol 38 (1) ◽  
pp. 19-29 ◽  
Author(s):  
Margaret Richold ◽  
Marion F. Robinson ◽  
R. D. H. Stewart

1.[75Se]selenite or [75Selenomethionine was injected into the coelomic cavity of fish. After 2 d or 14 d the muscle portion of the fish was removed and homogenized. The long-term fate in rats of an oral dose of each labelled homogenate was compared with that of an oral dose of [75Se]selenite or [75Se]selenomethionine mixed with unlabelled fish homogenate.2.Urinary and faecal radioactivity 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 75Se given as labelled fish homogenate was less complete than that of 75Se mixed with unlabelled homogenate, and the absorption of 75Se from the 14d-labelled fish homogenate derived from [75Se]selenite was less complete than that of 75Se from the other labelled homogenates.4.Urinary excretion of absorbed 75Se in the first 7 d was in the range 5-8 % absorbed dose and was slightly greater in the rats given 75Se as selenite or derived from selenite than in those given 75Se as selenomethionine or derived from selenomethionine. Endogenous faecal excretion of absorbed Se was similar in all groups, as also were tissue distribution of retained 75Se and long-term whole-body turnover rate.5.The results of these studies are compared with those of earlier studies of the metabolism in rats of [75Selenomethionine, [75Se]selenite, [75Sejselenocystine and 75Se incorporated in vivo into rabbit kidney. There were differences in the initial utilization of 75Se from these various sources but after the 1st week 75Se from all sources appeared to be metabolized similarly, suggesting that for rats dietary Se of all forms is ultimately incorporated into the same metabolic pool.

1975 ◽  
Vol 34 (3) ◽  
pp. 501-509 ◽  
Author(s):  
Christine D. Thomson ◽  
Bridget A. Robinson ◽  
R. D. H. Stewart ◽  
Marion F. Robinson

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.


1975 ◽  
Vol 33 (1) ◽  
pp. 45-54 ◽  
Author(s):  
Christine D. Thomson ◽  
R. D. H Stewart ◽  
Marion F. Robinson

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.


2017 ◽  
Vol 64 (1) ◽  
pp. 7-9
Author(s):  
I. Kazimierová ◽  
L. Pappová ◽  
M. Šútovská ◽  
S. Fraňová

AbstractBackground:Fisetin, a derivate from the flavonol group may possess a variety of pharmacological effects. The aim of the presented study was to evaluate the bronchodilatory effect of fisetin after the acute or the chronic administration to guinea pigs with allergic airway inflammation.Methods:Experimental animals were sensitized and challenged by ovalbumin. Fisetin was administered in dose 5mg/kg/p.o., either once after the end of 21-days sensitization or daily during the 21-days sensitization. By using the whole-body plethysmograph, we monitored the specific airway resistance, a parameter of airway hyperreactivityin vivo. The changes of the specific airway resistance were evaluated after the short-term inhalation of the bronchoconstriction mediator-histamine (10−6mol.1−1).Results:Our results showed that the short-term as well as the long-term administration of fisetin caused decrease of the specific airway resistance values. The bronchodilatory effect of fisetin was comparable to the long-acting beta2sympathomimetic – salmeterol after the long-term administration. The measurements of the bronchodilatory activity after single administration have revealed more prolonged effect of fisetin comparing to the short-acting beta2sympathomimetic – salbutamol, as this remained even after the 5 hours, when salbutamol was already ineffective.Conclusion:In conclusion, flavonol – fisetin has shown bronchodilatory potential. In the light of this fact, fisetin may represent potential substance that can be effective in both prevention as well as control of airway inflammation symptoms.


2009 ◽  
Vol 49 (6) ◽  
pp. 468 ◽  
Author(s):  
P. L. Greenwood ◽  
L. M. Cafe ◽  
H. Hearnshaw ◽  
D. W. Hennessy ◽  
S. G. Morris

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.


1997 ◽  
Vol 31 (3) ◽  
pp. 264-270 ◽  
Author(s):  
M. Santos ◽  
K. J. H. Wienk ◽  
M. W. Schilham ◽  
H. Clevers ◽  
M. de Sousa ◽  
...  

An improved and sensitive method for studying iron absorption in mice with alterations in body iron stores is described. Mice with varying iron status were given a double isotope-labelled test dose containing 59Fe and 51Cr as a non-absorbable indicator, via an oroesophageal needle. Using a whole-body counter it was possible to measure in vivo the initial mucosal iron uptake and long-term iron retention and to calculate mucosal iron transfer. A significant difference was demonstrated between normal and both anaemic and dietary iron-loaded mice with regard to the various steps of iron absorption. When mice were tested twice for iron absorption, the results were highly reproducible. In conjunction with other parameters, the method described is useful in studying the mechanism and the regulation of iron absorption in mice.


2019 ◽  
Author(s):  
Mary T. Doan ◽  
Michael D. Neinast ◽  
Erika L Varner ◽  
Kenneth Bedi ◽  
David Bartee ◽  
...  

AbstractAnabolic metabolism of carbon in mammals is mediated via the one and two carbon carriers S-adenosyl methionine and acetyl-coenzyme A (acetyl-CoA). In contrast, anabolic metabolism using three carbon units via propionate is not thought to occur. Mammals are primarily thought to oxidize the 3-carbon short chain fatty acid propionate by shunting propionyl-CoA to succinyl-CoA for entry into the TCA cycle. We found that this may not be absolute and that in mammals one non-oxidative fate of two units of propionyl-CoA is to condense to a six-carbon trans-2-methyl-2-pentenoyl-CoA (2M2PE-CoA). We confirmed this pathway using purified protein extracts provided limited substrates and confirmed the product with a synthetic standard. In whole-body in vivo stable isotope tracing with infusion of 13C-labeled valine achieving steady state, 2M2PE-CoA formed via propionyl-CoA in multiple murine tissues including heart, kidney, and to a lesser degree in brown adipose tissue, liver, and tibialis anterior muscle. Using ex vivo isotope tracing, we found that 2M2PE-CoA formed in human myocardial tissue incubated with propionate to a limited extent. While the complete enzymology of this pathway remains to be elucidated, these results confirm the in vivo existence of at least one anabolic three to six carbon reaction conserved in humans and mice that utilizes three carbons via propionate.Highlights- Synthesis and confirmation of structure 2-methyl-2-pentenoyl-CoA- In vivo fate of valine across organs includes formation of a 6-carbon metabolite from propionyl-CoA- Ex vivo metabolism of propionate in the human heart includes direct anabolism to a 6-carbon product- In both cases, this reaction occurred at physiologically relevant concentrations of propionate and valine- In vitro this pathway requires propionyl-CoA and NADH/NADPH as substrates


2016 ◽  
Vol 2 ◽  
pp. 14
Author(s):  
M. Di Mascio ◽  
S. Srinivasula ◽  
I. Kim ◽  
P. DeGrange ◽  
A.S.t. Claire ◽  
...  

1974 ◽  
Vol 142 (3) ◽  
pp. 673-683 ◽  
Author(s):  
Eric H. Karunanayake ◽  
David J. Hearse ◽  
Graham Mellows

[14C]Streptozotocin was synthesized specifically labelled at three positions in the molecule. The biological activity of synthetic streptozotocin was characterised by studies in vivo of its diabetogenic activity and its dose–response curves. After this characterization the excretion pattern of all three labelled forms of streptozotocin was studied. With [1-14C]streptozotocin and [2′-14C]streptozotocin the injected radioactivity was excreted (approx. 70% and 80% respectively) mainly in the urine, the greater part of the excretion occurring in the first 6h period; small amounts (approx. 9% and 8% respectively) were found in the faeces. In contrast, with [3′-methyl-14C]streptozotocin a much smaller proportion (approx. 42%) of the injected radioactivity was excreted in the urine, the major proportion appearing in the first 6h, whereas approx. 53% of the injected radioactivity was retained in the carcasses. In whole-body radioautographic studies very rapid renal clearance and hepatic accumulation of the injected radioactivity was observed with all three labelled forms of the drug. There was some evidence for biliary and intestinal excretion. Major differences were apparent in the tissue-distribution studies, with each of the three labelled forms, particularly with [3′-methyl-14C]streptozotocin. There was no accumulation of [1-14C]streptozotocin in the pancreas for the 6h period after administration. However, with [3′-methyl-14C]streptozotocin (and also [2′-14C]streptozotocin) there was evidence of some pancreatic accumulation after 2h. The results indicate that streptozotocin is subjected to considerable metabolic transformation and to rapid renal clearance. The implication of these suggestions is evaluated with particular reference to the diabetogenic action of streptozotocin.


1976 ◽  
Vol 51 (4) ◽  
pp. 421-425 ◽  
Author(s):  
A. W. Segal ◽  
G. Gregoriadis ◽  
J. P. Lavender ◽  
D. Tarin ◽  
T. J. Peters

1. Liposomes containing 111In-labelled bleomycin were injected intravenously into two patients. One patient had a hepatoma and the other had secondary adenocarcinomatous deposits in the liver. 2. The tissue distribution of 111In was determined by whole-body scanning and by measurement of the radioactivity in organs at autopsy. 3. Scans in vivo and post-mortem measurement of radioactivity indicated that liposomes accumulate predominantly in the liver, but that there is no selective uptake of liposomes by the malignant tissue. 4. The subcellular distribution of radioactivity in the liver was measured 90 min after injection by fractionation of percutaneous liver biopsies on sucrose density gradients. 5. Radioactivity within the liver was concentrated in lysosomes. 6. Electron microscopy of tissue obtained before the administration of liposomes revealed particles morphologically indistinguishable from liposomes in hepatoma cells and hepatocytes.


1973 ◽  
Vol 30 (1) ◽  
pp. 139-147 ◽  
Author(s):  
Christine D. Thomson ◽  
R. D. H. Stewart

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.


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