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Biomedical subjects

M Cikrt

Publications and source records attributed to M Cikrt.

At least 73 records · Page 4Linked to original sources
PubMed1981

Biliary excretion of cobalt in rats.

The excretion of 58Co2+ via bile, urine and intestinal wall after intravenous administration of 58CoCl2 in two doses (177 and 1770 micrograms of Co2+ per kg B. Wt.) was studied in rats. The cumulative biliary excretion reached 24 hours after administration of lower dose 2.67 +/- 1.98% and higher dose 7.33 (4.6-10.9) % of the amount given. The highest excretion rate of 58Co was detected between 10 and 30 minutes after administration. After administration of higher dose of 58Co the lower urinary excretion was observed [73.6 +/- 4.0% resp. 47.9% (45.5-52.5)] of the amount given. There were no differences between both doses studied in the excretion of 58Co via the wall of gastrointestinal tract.

Animals↗
PubMed1980

Distribution and excretion of 203Hg2+ in rats after unitiol, spironolactone and polythiol resin treatment.

Rats were given 203HgCl2 i.v. at a dose level of 120 microgram of Hg2+ per rat. The effect of unitiol (UNI; sodium 2, 3-dimercaptopropanosulphonate) and a combined UNI, spironolactone (SPL) and polythiol resin treatment on wholebody retention, organ distribution and excretion were studied for 48 h. In both treated groups significant increases in excretion and decreases in whole-body retention of 203Hg were observed. In the combination-treated group significantly lower values of 203Hg in plasma, kidney and brain were found.

Animals↗
PubMed1980

Biliary iron excretion in rats following pyridoxal isonicotinoyl hydrazone.

Biliary excretion of iron after administration of pyridoxal isonicotinoyl hydrazone (PIH), a recently identified effective iron-chelating agent, was investigated in rats. PIH administered both intraperitoneally and orally was shown to increase significantly 59Fe excretion into bile of rats which had previously been injected with 59Fe-transferrin to label hepatic parenchymal cells. 59Fe-PIH appears in bile as early as 15 min after chelator administration and the peak of 59Fe-radioactivity in bile is seen 1--5 h following intraperitoneal PIH injection. PIH, administered intraperitoneally, 125--250 mg/kg, increased 24 h biliary radioiron excretion about 35 times and in addition increased urinary and faecal iron excretion. When PIH was given immediately before 59Fe-transferrin, 24 h cumulative biliary 59Fe excretion was even higher. PIH was also demonstrated to increase biliary excretion of radioiron released from 59Fe-haemoglobin catabolysed in reticuloendothelial cells. The effect of PIH was confirmed by estimation of biliary iron concentration using the method of atomic absorption spectrophotometry. Repeated PIH administration to rats decreased 59Fe radioactivity in liver and kidney and increased urinary and faecal iron excretion.

Animals↗
PubMed1980

Effect of some chelating agents on the biliary excretion of mercury. 2. Relationship between the excretion of mercury and its binding to bile fractions.

Mercury binding to bile components and the correlation between the amount of mercury bound in the bile fraction 2 and the rate of mercury biliary excretion were studied in female rats exposed to intravenously injected HgCl2 after pretreatment with a series of 14 chemical agents. After pretreatment with the tested agent, 203Hg was detectable both in the bile fraction 1 and 2. Distribution pattern of 203Hg between the two fractions appeared to be linked with the chemical structure of the formed mercury complex. Pretreatment with these agents did not inhibit the formation of the bile fraction 3. By their influence on the 203Hg distribution between the bile fractions 1 and 2, the tested agents can be roughly divided into 3 groups: the content of 203Hg in the bile fraction 2 is about 10--20% and does not change significantly within the first 24 hours after 203 HgCl2 injection (cysteine, penicillamine, disodium ethylenediaminotetraacetate -- Na2EDTA, sodium diethyldithiocarbamate, sodium alanindithiocarbamate, acrylonitrile); the the 203Hg content in the bile fraction 2 increases (thiophenolacetate); the content of 203Hg in fraction 2 is initially several times higher than that in the bile fraction 1, but then decreases during the first 24 hours (2,3-dimercaptopropanol -- BAL, sodium 2,3-dimercaptopropanesulphonate, spironolactone, Thiomestron). The rate of mercury biliary excretion (Rb) was found to be closely correlated with the relative amount of mercury present in the bile fraction 2 (a2), if a2 > 30%, both in vivo (Rb = 1.077 a2 + 0.758) and invitro (Rb = 1.067 a2 + 0.519) experiments. Practically identical values of the constant accompanying a2 in the two equations seem to indicate that one of the decisive factors influencing the rate of mercury biliary excretion in rats is rather the mercury affinity for the bile fraction 2 components than the agent-induced mercury transport mechanisms. For a2 < 30% the correlation is non-linear and the excretion is rather inhibited than enhanced.

Animals↗
PubMed1980

Effect of some chelating agents on the biliary excretion of mercury. 1. Excretion kinetics and distribution of mercury in the organism.

Wistar strain female rats were used to study the impact of 1-cysteine,D,L-penicillamine, EDTA, sodium N,N-diethyldithiocarbamate, BAL, Unitiou, Spironolactone, Thiomestron and thiophenolacetate on excretion kinetics and distribution pattern of 203Hg injected intravenously in a dose of 120 microgram 203Hg2+ per rat. A considerably enhanced biliary excretion of mercury was observed after pretreatment with Spironolactone, Unitiol, BAL and Thiomestron. The action of these agents persisted for only 2--3 hours after mercury application. The highest urinary excretion of mercury was recorded after pretreatment with Unitol and BAL. All the tested agents, particularly thiophenolacetate, turned out to enhance mercury excretion through intestinal wall cells. Pretreatment with the tested agents caused also considerable changes in the pattern of mercury distribution in the rat organism.

Animals↗
PubMed1980

Biliary excretion of 74As and its distribution in the golden hamster after administration of 74As (III) and 74As (V).

Biliary excretion of arsenic and its distribution in the organism were studied in golden hamsters after administration of Na3(74)AsO3 and Na2H74AsO4 solutions. Significant differences between the two valency forms of arsenic were found in the biliary excretion rate as well as in the cumulative biliary excretion of 74As. The arsenic biliary excretion after treatment with 74AS [III] [4.98 /+- 7.1, or 0.6 [0.2 - 1.1] percents of the administered dose] than that after 74As [V] application. On the other hand, arsenic excretion in the urine and stool were higher after the administration of pentavalent arsenic. The contents of 74As in the liver, kidneys, blood plasma and GIT wall were higher after the application of 74As [III]. It has been again confirmed tha compared to rats the hamster [similarly as the other laboratory animals] exhibits a significantly lower concentration of 74As in red blood cells [differences ranged by 2 orders of magnitude].

Animals↗
PubMed1979

Effects of dosage and cadmium pretreatment on the binding of cadmium in rat bile.

The effects of dosage and of cadmium pretreatment on the binding of cadmium in rat bile were studied. With increasing dose a higher cumulative biliary excretion of Cd was observed and a higher percentage of the Cd was excreted in a low-molecular-weight form. On the other hand, after cadmium pretreatment, a decrease in the cumulative biliary excretion of cadmium was observed but a greater percentage of that excreted into the bile was bound to high molecular weight compounds.

Animals↗
PubMed1979

Biliary excretion and distribution of 51Cr(III) and 51Cr(VI) in rats.

The biliary excretion and distribution of 51Cr after intravenous administration of 51Cr(III) (61CrCl5) or 51Cr(VI) (Na252CrO4 . 4 H2O) was studied in rats. The cumulative biliary excretion of 51Cr reached 24 hrs after the injection was significantly higher after administration of 51Cr(VI) than after 51Cr(III) 3.51+/-0.7% and 0.51+/-0.05% of administered dose, respectively). This difference was especially due to a higher rate of biliary excretion of 51Cr in the first hours after 51Cr(VI) administration. The excretion of 51Cr via faeces was also higher after administration of 51Cr(VI) (7.35+/-0.45%) OF ADMINISTERED DOSE, AS AGAINST 4.23+/-0.23% after 51Cr(III). On the other hand, no significant difference in urinary excretion of 51Cr was found. Statistically significant differences were also observed in the distribution of 51Cr in the organism after administration of both valence states of the metal.

Animals↗
PubMed1979

Penetration of beryllium through the placenta and its distribution in the mouse.

Penetration of beryllium through the placenta and its distribution in the organs after intravenous administration of BeCl2 in a dose of 0.1 mg/kg was studied in a series of experiments on ICR SPF mice. To trace the fate of beryllium, an isotope in the form of 7BeCl2 in an amount of 111kBq per animal was used. This dose was administered to a group of females before fertilization, on the 7th and 14th day of pregnancy, and to control animals. The animals were killed on the 18th to 19th day of pregnancy and the content of beryllium in the foetuses and its distribution in the organs of the mothers were determined by measuring activity. It has been found that beryllium penetrates through the placenta with difficulty, however, part of the dose administered circulated in the blood long enough for Be to penetrate the foetuses. Of interest is the finding that beryllium in the dose administered influenced the number of foetuses of the exposed females. This finding deserves detailed evaluation in the test of dominant lethal mutations.

Animals↗
PubMed1978

The influence of unithiol and spironolactone on the biliary excretion of 203Hg in rat.

Rats with cannulated bile ducts were intravenously given 203HgCl2 in the dose of 120 microgram of Hg2+ per rat. Intramuscular administration of Unithiol (sodium 2,3-dimercaptopropanosulphonate) 4 and 7 h after 203Hg injection markedly increased both biliary and urinary excretion of 203Hg. In rats with Spironolactone (17-Hydroxy-7alpha-mercapto-3-oxo-17alpha-pregn-4-ene-21-carboxylic acid, gamma-lactone, acetate) pretreatment the effect of Unithiol on the biliary excretion of 203Hg was enhanced. Urinary excretion of mercury was lowest in comparison with Unithiol treated group.

Animals↗
PubMed1976

Biotransformation of As(III) to As(V) and arsenic tolerance.

The paper deals with excretion of As(III) and As(V) in the urine of mice exposed to a toxic concentration of As(III) (250 mg/1) in drinking water. After the exposures of 2, 6, and 8 days, the mice were given i.m. a solution of 74As(III) labeled sodium arsenite in a dose of 1.3 mg As(III)/kg b.w. and an activity of 3 muCi/l ml. After the sacrifice of the animal, the urine was drawn off directly from the bladder. The urine samples were subjected to separation of As(III) from As(V) by using a paper radiochromatography technique. The results showed that unexposed control mice excreted one-half of the administered As(III) in the form of As(V). Mice exposed to arsenic in drinking water exceted already, after 2 days of exposure, four-fifths of the applied As(III) in the form of As(V), after 4 days of exposure the proportion of As(V) was more than 95%, and after 8 days of exposure only traces of As(III) were present. The authors discussed the possibility of the biotransformation of As(III) to As(V) on arsenic tolerance.

Animals↗
PubMed1975

Biliary excretion of 64Cu, 65Zn and 203Hg in the rat with liver injury induced by CCl4.

In rats the effect of a chronic administration of CCl4 on the excretion and disstribution of 64Cu, 65Zn, and 203Hg was investigated. The bilary excretion of these metals was studied with particular attention. It was found that total excretion of 64Cu, 65Zn, or 203Hg from the organism did not change significantly in comparison with the control groupp, but the ratio of individual excretion pathways did change. The course of excretion curves regarding the bile in exposed animals is prolonged. The histologic examination of the livers revealed a large interindividual variability in the response of the liver tissue to the same CCl4 exposure. Differences in distribution in the kidneys and livers in exposed and control animals was also found.

Animals↗
PubMed1975

Role of bile in intestinal absorption of 203Pb in rats.

The author studied absorption of 203Pb after administering intraduodenally 203Pb eliminated with bile. The results obtained were compared with absorption of 203Pb administered into the duodenum as 203PbCl2 in rats forming 2 groups, one with bile ducts cannulated, the other intact. It was found that bile played an important role in absorption of Pb from the gastrointestinal tract. Absorption of Pb203 is significantly reduced if the bile is drained off by means of a canula.

Animals↗
PubMed1975

Biliary excretion of 7Be and its distribution after intravenous administration of 7BeCl2 in rats.

Wistar female rats were given two i.v. doses of 7BeCl2 (dose A = 0.025 mg Be2+/kg b.w.; dose B = 0.25 mg Be2+/kg b.w.). The rats were decapitated at 5, 24, and 48 hrs after administration. The kinetics of 7Be bile excretion during the 5 hrs after administration, as well as 7Be retention in selected organs and the urine and stool excretion of beryllium were investigated. Significant differences between the effect of both doses were found particularly in the shape of biliary excretion curves of 7Be. Unproportionally higher 7Be blood levels after a higher dose persisted for a longer period of time. The decrease of 7Be in blood after a higher dose between the 5th and 24th hr after the administration was accompanied by an increased content of 7Be in the liver and spleen as well as by an increased urine excretion. The results obtained tend to prove that the reticuloendothelial system mainly participated in beryllium retention. Urine represents the main excretion route of beryllium after a parenteral administration.

Animals↗