A kinetic model of copper metabolism in sheep

1980 ◽  
Vol 31 (4) ◽  
pp. 773 ◽  
Author(s):  
KM Weber ◽  
RC Boston ◽  
DD Leaver
Keyword(s):  
Rate Constants ◽  
Copper Content ◽  
Copper Metabolism ◽  
Normal Liver ◽  
Dry Weight ◽  
Compartment Model ◽  
Flow Rates ◽  
Liver Copper ◽  
Copper Status ◽  
Three Compartment Model

A three-compartment model was developed to provide a simple kinetic description of the metabolism of copper in six sheep with liver copper concentrations of 433�51 ppm ( mean � SD dry weight). This was achieved by measuring the radioactivity in samples of blood, liver, urine and bile as a function of time after the intravenous administration of c. 1.4 mCi of 64Cu. Sizes of compartments, flow rates and rate constants were evaluated and validated experimentally by measuring the excretion of copper in urine and bile and its accumulation in the liver. The model postulates two separate mechanisms for the handling of copper by the liver, and biliary copper excretion was not related to total liver copper content. The model was tested in sheep with a wider range of liver copper concentrations, and the copper in the two compartments (C2 and C3), attributed to liver, corresponded to the actual liver copper content when this was between 30 and 70 mg. The rate constants also responded consistently to increased liver copper status. Within the 'normal' liver copper range of 50-70 mg, the three-compartment model was closed but outside this range, the undefined parameter K03 was no longer zero. This response suggests that copper is moving from C2 and C3 to either supply tissue requirements or be redistributed in an additional storage compartment.

Studies on copper and cobalt therapy of cattle in central coastal Queensland

1967 ◽  
Vol 18 (1) ◽  
pp. 169 ◽  
Author(s):  
GI Alexander ◽  
JM Harvey ◽  
JH Lee ◽  
WC Stubbs
Keyword(s):  
Growth Response ◽  
Copper Deficiency ◽  
Copper Metabolism ◽  
Subcutaneous Injections ◽  
Liver Copper ◽  
Copper Status ◽  
Period 2 ◽  
Copper Supplementation ◽  
Copper Therapy ◽  
Effect Of Copper

Four experiments described determined the effect of copper and cobalt therapy on the growth and productivity of cattle on the marine plains of central coastal Queensland. Copper was administered by subcutaneous injections of copper glycinate, and cobalt by dosing per os with heavy cobalt pellets. The growth of weaned cattle was significantly improved by copper, particularly from June to October when limited palatable feed on the high ground forced the animals to forage on the para grass swamps. During the same period, 2-year-old heifers also showed a growth response to copper. Their conception rate increased after 19 months of copper therapy but not after 10.5 months. The growth rate of their calves bas significantly increased by copper supplementation. Liver copper concentrations were always low in untreated cattle. Copper therapy maintained these reserves at higher levels, which varied according to the season and the rate of growth of the animals. Calves born to treated cows had higher initial liver copper reserves than those from untreated cows, but in the absence of copper therapy these reserves declined to low and comparable levels in all calves at weaning. Pasture analyses suggest that the copper deficiency revealed was due to interference with copper metabolism rather than to a low copper status in the diet; this interference did not appear to be due to molybdenum. Weaned cattle appeared to respond to cobalt during 1960 but not subsequently, while the cows and calves showed no response. The vitamin B12 status in liver and serum appeared adequate in both treated and untreated cattle.

Some effects of aldosterone on sodium kinetics and distribution in porcine arterial wall

1983 ◽  
Vol 244 (4) ◽  
pp. R553-R557
Author(s):  
J. G. Llaurado ◽  
J. A. Madden ◽  
G. A. Smith
Keyword(s):  
Rate Constants ◽  
Compartment Model ◽  
Transport Rate ◽  
Tissue Water ◽  
Intracellular Space ◽  
Three Compartment Model ◽  
Carotid Wall ◽  
Kinetics Of ◽  
Total Tissue

Transport rate constants for Na+ exchanges and relative Na+ compartment distribution in isolated pig carotid wall were determined with the aid of 22Na+ as tracer that was continuously washed out. A three-compartment model consisting of 1) extracellular, 2) intracellular, and 3) subcellular spaces was found to represent adequately the kinetics of 22Na+. It was found that d-aldosterone (0.85 X 10(-6) M) added to the incubating medium for 3 h causes significant changes in two transport rate constants and in the distribution of sodium within different compartments. Total tissue water, nonradioactive sodium (tracee), and potassium are not altered by aldosterone; however, when amounts of Na+ tracee are calculated for each compartment, aldosterone significantly reduces the amount of Na+ in compartment 2. Overall, the results indicate that aldosterone induces a translocation of Na+ into the extracellular space at the expense of the intracellular space. The findings are interpreted in the light of recent reports on the role of altered function of the Na+-K+ pump under aldosterone influence or arterial hypertension.

The copper status of some helminth parasites, with particular reference to host-helminth relationships in the gastro-intestinal tract of cattle

1961 ◽  
Vol 12 (6) ◽  
pp. 1188 ◽  
Author(s):  
KC Bremner
Keyword(s):  
Copper Content ◽  
Fasciola Hepatica ◽  
Total Content ◽  
Dry Weight ◽  
Clinical State ◽  
Trematode Species ◽  
Helminth Parasites ◽  
Copper Status ◽  
Copper Supplementation ◽  
Gastro Intestinal Tract

The copper content was determined in samples of 12 nematode, four cestode, and two trematode species collected from a variety of hosts infected either naturally or experimentally. Copper concentrations varied considerably from species to species, the lowest value recorded being 2 p.p.m. copper (dry weight basis) in the cestode Moniezia benedeni and the highest 604 p.p.m. in the nematode Haemonchus placei, both from cattle. Both the total content and the concentration of copper varied among mature individuals of the same population of the liver fluke, Fasciola hepatica, collected from cattle. Copper levels varied greatly in samples of H. placei and Oesophagostomum radiatum from cattle drawn from different host individuals, whereas values for Bunostomum phlebotomum and M. benedeni also from cattle varied little from host to host. Copper concentrations in samples of H. placei and O. radiatum, recovered from the abomasum and large intestine respectively of experimentally infected calves supplemented daily with copper sulphate, were considerably higher than those in samples from unsupplemented calves. With both species, the increases in worm copper levels were associated with increases in concentrations of soluble copper in the environment. It is suggested that soluble copper in environmental fluids can be absorbed through the cuticle of these helminths. Copper supplementation of the host's diet, on the other hand, had no effect on the copper content of B. phlebotomum Furthermore, the concentration of copper in solution in the contents of the duodenum and jejunum was not elevated significantly by the supplementatlon. The hypothesis that the intestinal helminths of bovines compete with the host for copper was examined, and it is concluded that in dairy calves in southeastern Queensland parasitic gastro-enteritis has a far greater significance as a disease entity in itself than as a factor contributing to the expression of a clinical state of copper deficiency.

Flow dependence of gas distribution and the pattern of inspiratory muscle contraction

1978 ◽  
Vol 45 (5) ◽  
pp. 733-741 ◽  
Author(s):  
M. S. Fixley ◽  
C. S. Roussos ◽  
B. Murphy ◽  
R. R. Martin ◽  
L. A. Engel
Keyword(s):  
Regional Distribution ◽  
Applied Pressure ◽  
Compartment Model ◽  
Gas Distribution ◽  
Flow Rates ◽  
Flow Dependence ◽  
Topographical Distribution ◽  
Lower Lung ◽  
Three Compartment Model ◽  
Accessory Muscles

We measured regional distribution of xenon-133 boli at 0.25, 0.75, and 1.5 l/s in four normal seated subjects during inspirations performed predominantly with intercostal and accessory muscles (IC) or with the diaphragm, accompanied by outward abdominal motion (Ab). In six additional subjects we inferred the topographical distribution of helium boli during similar breaths and flow rates from the slope of the alveolar plateau recorded during a slow expiration (less than 0.5 l/s). Distribution of the helium boli was studied during natural as well as IC and Ab inspirations. At each of the flow rates IC breaths distributed relatively more of the inspired bolus to upper lung regions than did Ab inspirations. Natural breaths at 0.25 l/s resulted in distributions similar to those of Ab inspirations, whereas at 1.5 l/s the distribution approached that of IC inspirations. A three-compartment model, representing upper, middle, and lower lung regions, was used to simulate bolus distribution. The experimental data showed substantial departure from predictions based on regional time constants alone. However, additional small differences in applied pressure (less than 0.50 cmH2O) between the regions satisfactorily accounted for the gas distribution.

Vertebral fractures and luxations in dogs and cats part 2: treatment and surgery options

2021 ◽  
Vol 26 (3) ◽  
pp. 15-19
Author(s):  
Ivona Orgonikova ◽  
Josep Brocal ◽  
Giunio Bruto Cherubini ◽  
Viktor Palus
Keyword(s):  
Spinal Cord ◽  
Vertebral Fractures ◽  
Vertebral Column ◽  
Compartment Model ◽  
Spinal Instability ◽  
Decompression Surgery ◽  
Implant Loosening ◽  
Bone Fragment ◽  
Three Compartment Model ◽  
Disc Extrusion

Assessing the presence of vertebral column instability is essential in animals with vertebral fractures or luxations. Spinal instability is most commonly assessed using a three-compartment model and unstable vertebral fractures and luxations require surgical stabilisation. In cases of compression of the spinal cord (by haematoma, traumatic intervertebral disc extrusion or bone fragment), decompression surgery is necessary. Prompt surgery prevents additional spinal cord damage, but the overall condition of the patient, including any concurrent injuries, needs to be continually kept in mind. The vertebral column can be stabilised using multiple techniques, such as screws, pins, polymethylmetacrylate and plating techniques, as well as external stabilisation and spinal stapling. Complications of spinal surgeries include haemorrhage, infection, neurological deterioration, particularly in cases of spinal stabilisations, implant loosening and failure.

Assessment of copper accumulation in archived liver specimens from cats

2020 ◽  
pp. 1098612X2096135
Author(s):  
Punyamanee Yamkate ◽  
Randi M Gold ◽  
Panagiotis G Xenoulis ◽  
Katja Steiger ◽  
David C Twedt ◽  
...  
Keyword(s):  
Infectious Disease ◽  
Hepatic Steatosis ◽  
Dry Weight ◽  
Reference Interval ◽  
Copper Accumulation ◽  
Zonal Distribution ◽  
Tissue Samples ◽  
Hepatic Copper ◽  
Liver Copper ◽  
Flame Atomic Absorption

Objectives The aim of this study was to assess hepatic copper concentrations and zonal distribution in cat liver specimens. Methods For this study, 121 archived, formalin-fixed, paraffin-embedded liver specimens from cats were used. Tissue sections were stained for copper with rhodanine and scored from 0 (no copper accumulation) to 5 (panlobular copper accumulation). The tissue specimens were then deparaffinized and hepatic copper concentrations were measured using flame atomic absorption spectroscopy. Results Tissue samples were categorized into four groups based on histopathologic findings: (1) no significant histopathologic hepatic changes (n = 66); (2) hepatic steatosis (n = 18); (3) inflammatory or infectious disease (n = 24); and (4) neoplasia (n = 13). Of the 121 specimens, 13 (11%) stained positive for copper, with three having a score ⩾3. Thirty-seven specimens (31%) had copper concentrations above the reference interval ([RI] <180 µg/g dry weight liver). Copper concentrations in cats with hepatic inflammatory or infectious disease were significantly higher than cats with hepatic steatosis ( P = 0.03). Copper-staining score and concentration were positively correlated ( rs = 0.46, P <0.001). Conclusions and relevance Despite the fact that 31% of specimens had copper concentrations above the RI, only 11% showed positive copper staining and only 2.5% had a score ⩾3. Our findings suggest that hepatic copper concentrations greater than the upper limit of the RI are relatively common in cats. Further studies to determine the factors that influence hepatic copper staining in cats and to establish contemporary RIs for hepatic copper in healthy cats are warranted.

Liver copper content of rats hypo- or hyperresponsive to dietary cholesterol

2003 ◽  
Vol 17 (3) ◽  
pp. 177-182
Author(s):  
Ingeborg de Wolf ◽  
Xandra Fielmich-Bouman ◽  
Ægidius Lankhorst ◽  
Bernard van Oost ◽  
Anton Beynen ◽  
...  
Keyword(s):  
Copper Content ◽  
Dietary Cholesterol ◽  
Liver Copper
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