PubMed Health⌕ Search

Biomedical subjects

A Babický

Publications and source records attributed to A Babický.

At least 19 recordsLinked to original sources
PubMed2005

Biological half-life of bromide in the rat depends primarily on the magnitude of sodium intake.

The parallel course of the excretion rates of bromide and sodium ions was demonstrated in adult male and female rats administered simultaneously with potassium 82Br-bromide and 24Na-sodium chloride. The animals were exposed to various intakes of sodium ions accompanied with five different anions: Br-, Cl-, HCO3-, ClO4-, and SCN-. Regardless of the anion accompanying the sodium ion, the excretion rates of 82Br- and 24Na+ ions were proportional to the magnitude of sodium intake in the animals. Hence, we have proved our hypothesis that the biological half-life of bromide depends on the magnitude of sodium intake rather than on the intake of chloride.

Animals↗
PubMed2002

Impact of high bromide intake in the rat dam on iodine transfer to the sucklings.

A significant impact of high bromide levels in the organism of the mother on iodine transfer to the sucklings was established in experiments with female Wistar rats. The observed decrease in iodine transfer to the young through mothers' milk and/or an increase in the bromide concentration in the milk, caused a decrease in body weight of the pups. Enhanced bromide levels also adversely affected the thyroid gland of the young. High bromide intake in the lactating dams caused a decrease in iodide accumulation in the mammary glands, and also an increase in iodide elimination through the kidneys.

Animals↗
PubMed2001

Effect of high bromide levels in the organism on the biological half-life of iodine in the rat.

In experiments on rats, a significant influence of an extraordinarily high bromide intake on the whole-body biological half-life of iodine was established. Very high bromide intake (1) decreased the amount of radioiodide accumulated in the thyroid, (2) changed the proportion between the amount of iodine retained in the thyroid and the total amount of absorbed iodine, (3) significantly shortened the biological half-life of iodine in the thyroid from approximately 101 h to 33 h in animals maintained on an iodine-sufficient diet and from 92 h to about 30 h in rats fed a low-iodine diet, and (4) changed the time-course (added a further phase) of iodine elimination from the body. These changes were caused, with high probability, by an increase of iodine elimination by kidneys due to an excess of bromide. The overall picture of iodine elimination in animals fed the low-iodine diet was similar to that in animals maintained on iodine-sufficient diet.

Animals↗
PubMed2001

High bromide intake affects the accumulation of iodide in the rat thyroid and skin.

The effect of a high bromide intake on the kinetics of iodide uptake and elimination in the thyroid and skin of adult male rats was studied. In rats fed a diet with sufficient iodine supply (> 25 microg I/d), the iodide accumulation in the skin predominated during the first hours after 131I iodide application. From this organ, radioiodide was gradually transferred into the thyroid. A high bromide intake (> 150 mg Br-/d) in these animals led to a marked decrease in iodide accumulation, especially by the thyroid, because of an increase in iodide elimination both from the thyroid and from the skin. In rats kept under the conditions of iodine deficiency (< 1 micro I/d), the iodide accumulation in the thyroid, but not in the skin, was markedly increased as a result of a thyrotropic stimulation. The effect of a high bromide intake (> 100 mg Br-/d) in these animals was particularly pronounced because the rates of iodide elimination were most accelerated both from their thyroid and from their skin.

Animals↗
PubMed2000

Bromide kinetics and distribution in the rat. I. Biokinetics of 82Br-bromide.

Biological half-lives of bromine in 15 different organs and tissues of the rat, in addition to the whole-body half-life, were determined by measuring the radioactive concentration of 82Br-bromide in samples of tissues collected at the time intervals of 12-396 h from animals that continuously (up to 17 d) received 82Br-labeled bromide in their drinking water. The half-life values, calculated from the experimental data by the method of gradual estimates of the parameters in question with the SPSS statistical program, ranged from 94.3+/-14.6 h in the thyroid gland to 235.0+/-88.9 h in liver. In most of the studied tissues, the biological half-lives of bromine were shorter than in the whole body, in which it equaled 197.8+/-22.2 h. Significant correlation between the values of the steady-state concentration of bromide and of the biological half-life was found for most tissues (except for liver). The steady-state concentrations of 82Br in tissues are probably proportional to the magnitude of bromide space, and, consequently, of chloride space.

Animals↗
PubMed2000

Bromide kinetics and distribution in the rat. II. Distribution of bromide in the body.

The distribution of 82Br-bromide in 15 different organs and tissues of rats has been determined by high-resolution gamma-ray spectrometry and by the scintillation counting technique at different times after the application of Na 82Br, either by subcutaneous injection or by continuous administration in the drinking water. The amount of 82Br-bromide in the various tissues reached its largest uptake within a few hours, and the concentration ratio of 82Br in the tissues to blood remained practically constant between 8 and 396 h after the application. The whole stomach of rats was the only organ of those investigated that had a larger uptake of 82Br than blood. Contrary to some previous findings, the concentration of radiobromide in the thyroid was found not to exceed that in the blood. A remarkably high concentration of 82Br was found in the skin, which represented, because of its large mass, the most abundant depot of bromide in the body of rats. The demonstrated excretion of bromide was mainly renal, at a rate of approximately 5% of the administered dose per 24 h.

Animals↗
PubMed1997

Biological half-life of bromine in the rat thyroid.

The biological half-life of bromine in the rat thyroid was determined by measuring the radioactivity of thyroids of animals which continuously received 82Br labelled bromide in their food. The value of this half-life (110 h) is practically the same as the biological half-life of iodine. The rate of establishing the I/Br concentration ratio in the thyroid depends on the biological half-life of bromine. The mechanism of this process depends on the state of iodine supply. When the supply is sufficient, the iodine concentration in the thyroid remains constant, while during iodine deficiency the iodine atoms are replaced by atoms of bromine.

Animals↗
PubMed1996

Interaction of bromine with iodine in the rat thyroid gland at enhanced bromide intake.

In experiments with rats, we have found that at enhanced intake of bromide, bromine does not replace chlorine in the thyroid; it replaces iodine. Under our experimental conditions, more than one-third of the iodine content in the thyroid was replaced by bromine. In the thyroid, bromine probably remained in the form of bromide and, in proportional to its increased concentration, the production of iodinated thyronines decreased, with the sum of the iodine and bromine concentrations being constant at the value of 20.51 +/- 1.16 mumol/g dry wt of the thyroid. In contrast to other organs, the biological behavior of bromine in the thyroid is not similar to the biological behavior of chlorine but resembles more that of iodine.

Animals↗
PubMed1996

Effect of increased bromide intake on iodine excretion in rats.

The time course of iodine excretion in adult male rats substantially differs from bromine excretion. Bromine is excreted at a single rate, whereas iodine evinces two excretion rates. Even a strong increase in bromide intake in experimental animals failed to affect the rate of iodine excretion but it lowered the fraction of iodine accumulated in the thyroid gland by 20% probably by affecting the transport of iodide into the thyroid gland.

Animals↗
PubMed1994

Effect of enhanced bromide intake on the concentration ratio I/Br in the rat thyroid gland.

Interaction of bromine with iodine was studied in the rat thyroid gland under the conditions of different bromide intake. Bromine and iodine in the thyroid dry weight were determined by instrumental neutron activation analysis (INAA). It was found that with increased bromide intake the bromine concentration in the thyroid gland increased with simultaneous decrease in the iodine concentration. The change in the I/Br concentration ratio depends on a number of halogen binding positions and on the bromide supply. The I/Br parameter reacts sensitively to the changes of bromide intake already in the region of low bromine concentration levels.

Animals↗
PubMed1993

Studies on the immunomodulatory effects of vitamin D.

The effect of vitamin D on T lymphocytes was investigated using the test of active E-rosettes formation. It was found that: 1. A single oral administration of 600,000 IU of vitamin D2 causes a significant increase in the formation of active E-rosettes. The peak of the increase was found 24 hours after the administration of vitamin D. The formation of E-rosettes the seventh day of the study was comparable with the pre-administration value; 2. Sera with higher concentration of 1,25-dihydroxyvitamin D[1,25(OH)2D] cause a significant increase in the formation of active E-rosettes; 3. Vitamin D is capable of reverting significantly the effect of a serum factor which suppresses the active E-rosettes formation. The authors observed a significant decrease in the effect of trypsin on the lymphocytes after oral administration of a single oral dose of 600,000 IU of vitamin D2. The trypsin-treated lymphocytes regained their lost capacity to bind sheep red blood cells (SRBC) when incubated with AB serum at 37 degrees C for 3 hours. The recovery of E-rosettes-forming capacity of trypsinised lymphocytes considerably increased when the cells were incubated with serum containing higher concentration of 1,25(OH)2D of 600,000 IU of vitamin D2.

Adjuvants, Immunologic↗
PubMed1990

The excretion of salt load by the developing chick embryo.

Salt loads (0.17 or 0.34 mmol Na+; 6 M NaCl solution labelled with 24Na) were administered into the amnion of 7-day-old chick embryos. The 24Na distribution in embryonic blood, amniotic and allantoic fluids was measured in 1, 2, 4, 8, 12 and 24 h intervals to assess the kinetics of salt load movements in particular egg compartments. The aim was to estimate the efficiency of the embryonic homeostatic apparatus to maintain ionic balance in the internal environment of the embryonic body. The Na+ concentration in amniotic fluid was expected to rise after salt loading by about 275 and 400 mM, respectively. More than 10% of the salt dose per ml appeared in the embryonic blood 2 h after salt load administration while only 0.2% were found in the urine (collected as allantonic fluid). The maximal rise of 24Na activity in the blood of salt-loaded embryos reached 11%-12% of the dose which corresponded to an increase of Na+ concentration by 19 and 41 mM, respectively. The maximum of 24Na activity appeared in the allantoic fluid with a delay of several hours and indicated an increment of Na+ concentration by 6% and 9% of the dose per ml in the case of salt-loaded embryos. The Na+ concentration in the allantoic fluid (urine) never exceeded that in the blood. The final Na+ activity (estimated in the blood 24 h after salt loading) was equal to 5% of the dose per ml in both cases, indicating a persistent elevation of Na+ concentration by 8.6 and 17.2 mM, respectively.

Allantois↗
PubMed1989

Coprophagy in young laboratory rat.

Coprophagy (ingestion of maternal faeces) was found in young laboratory rats between the ages of 16 and 28 days. The degree of this activity during the given period was not constant; a multiple increase on about the 25th day was followed by an abrupt drop and complete cessation coincided with the time of spontaneous weaning. Coprophagy did not appear in prematurely weaned young (at 16 days) which were given faeces and was protracted in undernourished young whose weaning time was prolonged. Young weaned rats without having ingested maternal faeces displayed relative hyperphagy for solid food. This early hyperphagy had later consequences for the feeding behaviour of adult males, which looked for food and consumed it more intensively in a new environment and also hoarded it. Defensive behaviour was not affected.

Animals↗
PubMed1989

Effect of mercury on selenium binding to rat lens proteins in vitro.

The effect of mercury in the incubation medium on selenium influx, efflux and distribution was studied in eye lenses of 14-day-old rats. The presence of mercury did not affect the uptake of selenium into a water-soluble protein fraction but increased considerably its content in water-insoluble proteins and thus also the selenium influx into experimental lenses. The efflux from experimental lenses yielded significantly lower amounts of released selenium, most of the selenium being bound to proteins. In contrast, efflux experiments with control lenses showed most of the selenium to be in the medium in the form of free anions. The selenium content in experimental lenses decreased after the efflux only in the fraction of water-soluble proteins, while the decrease in control lenses was found in both fractions and was relatively higher in water-insoluble proteins. During both influx and efflux experiments the lenses of both groups released a small of proteins, but no difference found between the two groups.

Animals↗
PubMed1989

Effect of 1,25-dihydroxycholecalciferol on fracture healing and on general posttraumatic skeletal response in rats.

The authors investigated the effect of 1,25-dihydroxycholecalciferol (1,25(OH)2D3) on the local healing process following an artificial fracture of the rat tibia and on the general posttraumatic response of the skeleton to local trauma. The results showed a significant increase in dry weight of fractured tibias as compared with contralateral intact bones which was due to the newly formed callus. 1,25(OH)2D3 significantly increased the weights of tibias which can be explained by its stimulatory effect on callus formation. The uptake of 85Sr into bones resembling the metabolic pathways of calcium was significantly higher in fractured bones as compared with intact ones. 1,25(OH)2D3 significantly reduced the uptake of 85Sr. There was a significantly higher whole body retention of 85Sr in the rats with fractured bones. The administration of 1,25(OH)2D3 significantly reduced the retention of 85Sr in the fractured bone and the concomitant reduction of the whole body retention of 85Sr most likely reflected the increase in intestinal calcium absorption induced by 1,25(OH)2D3 with the consequent decrease in the specific activity of 85Sr administered in a single injection. The general posttraumatic response was reflected by increased dry weight of non-fractured bones. 1,25(OH)2D3 showed a contributory effect on this increase which may indicate that the general response consisted in increased bone formation. The uptake of 85Sr in non-fractured bones was reduced which was also most probably due to a decrease of specific activity of 85Sr. 1,25(OH)2D3 significantly accentuated the reduction of the uptake.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1988

Selenium metabolism in rats after administration of toxic doses of selenite.

We studied organ concentration, excretion and excreted forms of selenium in young and adult rats after a single s.c. injection of a sublethal dose of 75Se-selenite. In the young about a 10-fold higher concentration of 75Se in blood, liver, kidneys and In the young, about a 10-fold higher concentration of 75Se in blood, liver, kidneys and heart was found at all the experimental intervals studied (1-7 days). The highest 75Se concentration in the young was in the liver while in the adults it was found in the kidneys. The spectrum of radioselenium metabolites in the urine was the same in both groups. However, the main product excreted by young rats was 75Se-glutathione selenotrisulphide and an unidentified neutral substance while it was the trimethylselenonium ion in the adults. Ontogenetic differences in selenium metabolism could be one of the factors underlying the differences in the response of the young and the adult rats to toxic doses of selenite.

Aging↗