I. Šimonović

Reduction of lead absorption from the intestine in newborn rats.

Abstract The effect of calcium, phosphate, and alginate additives to the milk on lead absorption from the intestine was studied in 5–7-day-old rats. The animals were artificially fed over a period of 8 hours with cows milk and with milk with calcium chloride, potassium dehydrogen phosphate, and sodium alginate additives to which tracer amounts of carrier-free lead-203 were added. The animals were returned to their mothers and sacrificed 90 hours later. Lead-203 was determined in the whole body before and after removal of the intestinal tract, and also in the liver and in the kidney. The retention of lead-203 in the body and organs was highest in the group of animals fed cows milk. The retention of lead-203 was about 1.4 times lower in animals with calcium and phosphate milk additives and approximately 2.5 times lower in animals with calcium, phosphate, and alginate additives.

Age and intestinal retention of mercury and cadmium in rats

The site of cadmium and mercury retention in the intestine was determined in 6-day-old sucklings and 6-week-old weaned rats 6 days after oral administration of 115mCd and 203Hg. The ileum was found to be the main site of intestinal retention of both cations in sucklings but not in weaned rats. Other age- and element-specific differences in the site of metal retention in the intestine were also found. These differences indicate that even in neonates, metal absorption might be a more specific process than previously assumed.

Simultaneous reduction of radioactive strontium, caesium and iodine retention by single treatment in rats

The effect of a mixture of calcium alginate, iron (III) ferrocyanide and potassium iodide added to rat diet on 85Sr, 137Cs and 131I metabolism and health was investigated in female rats after four weeks of treatment. The retention of these radioisotopes was determined in the whole body and critical organs six days after 85 Sr and 137CS and one day after 131I oral administration. The health effect of the mixture was evaluated by measuring body weights, haematological parameters, concentrations of iron, zinc and manganese in the kidneys, liver and femur, bone parameters (femur composition and morphometry) and by a histopathological examination. The mixture reduced 85Sr retention in the femur 11 times, 137Cs retention in the thigh muscle 102 times and 131I retention in the thyroid 134 times. Treated animals were in good health and the only differences found between the control and experimental rats were slightly lower haemoglobin values in the blood and a slightly lower iron concentration in the liver. It is concluded that the mixture was very efficient for decreasing body retention of three important fission products and that it can be used over long periods without causing adverse health effects.

Influence of calcium intake, age and sex on bone.

ConclusionsOur results indicate that both calcium intake and hormonal factors are important for the maintenance of bone structure. These findings might be relevant in setting up standards for calcium requirement.

The effect of iron additive to milk on cadmium, mercury, and managanese absorption in rats

Abstract Six-day-old sucklings and 6-week-old female rats were used in the experiment to estimate whether low iron content of milk is the reason for increased gastrointestinal absorption of metals. The absorption of 115mCd, 203Hg, and 54Mn was determined by measuring the body retention (whole body, carcass, and gut) 6 days after oral administration. To sucklings radioisotopes were administered by artificial feeding with cows milk with or without 100 ppm Fe additive. Iron addition had no influence on metal absorption at this age. The same radioisotopes were administered by stomach tube to older animals fed rats diet or milk with or without 100 ppm Fe additive. Increased iron content of milk decreased the absorption of all metals. For mercury and cadmium most of this effect was due to decreased gut retention and only partly to decreased carcass retention. It is concluded that the high absorption of metals in sucklings is not likely to be due to the low iron content of milk and also that iron does not interact with cadmium, mercury, and manganese in the absorption process at this age.

Effect of rat's diet on 85Sr, 115mCd, and 203Hg absorption in suckling rats

Abstract Six-day-old suckling rats were artificially fed over 8 hr with cows milk or rats diet labeled with 85 Sr, 115 m Cd, or 203 Hg. The whole-body radioactivity was determined in a double-crystal scintillation counter every 24 hr over a 6-day period. Rats diet caused a reduction in the whole-body retention of all radioisotopes which was highest for 203 Hg and lowest for 85 Sr. All sucklings were killed 6 days after the radioisotope administration and the radioactivity was determined in the carcass and in the gut. Rats diet reduced carcass retention by about 10% for 85 Sr, and two and three times for 115 m Cd and 203 Hg, respectively. Rats diet also reduced gut retention by about 20% for 85 Sr, two times for 115 m Cd and eight times for 203 Hg. It is concluded that dietary factors are partly responsible for the high metal absorption in sucklings. This specially applies to mercury because rats diet caused a considerable reduction in the whole-body retention of this metal primarily by decreasing its gut retention.

The Effect of Some Dietary Additives on Calcium and Strontium Absorption in Suckling and Lactating Rats

SummaryThe effect of calcium, phosphate and alginate additives to the diet on calcium-47 and strontium-85 absorption from the gut has been investigated in suckling and lactating rats.Suckling rats aged 5–7 days were artificially fed on cows milk (8 hours a day during a period of 10 days) containing tracer amounts of calcium-47 and strontium-85 to which various amounts of calcium, phosphate and alginate were added. Variation in the calcium by seven-fold and in the phosphate by five-fold caused only minor changes in the absorption of radiostrontium from the gut and no changes in the percentage calcium-47 absorption. The results indicate that the total absorption of calcium was independent of the phosphate level and proportional to the calcium concentration in the milk. The addition of alginate to milk caused a two-fold reduction in radiostrontium retention by suckling rats without affecting calcium absorption from the intestine.The increased strontium absorption normally found in lactating rats was prevent...

Effect of milk on mercury absorption and gut retention in rats

The retention of 203Hg was studied six days after a single oral or intraperitoneal administration to six week old female albino rats fed rats diet or milk. After oral administration rats on milk diet had a two times higher retention of mercury in the gut-free carcass and a 23 times higher retention in the gut than animals on rats diet. Changes in diet had very little influence on mercury retention after intraperitoneal administration. The higher gut and carcass rentions of mercury in animals on milk diet could be prevented or reduced by transferring rats from milk diet to rats diet several days after an oral dose of mercury. These results might be relevant for interpreting high gut and carcass retention after oral administration of some metals in suckling and changes which occur at weaning.

131I Uptake in Human Thyroid after Antidote Treatment for Mixed Fission Products Contamination

The efficacy of a mixed antidote treatment in blocking 131I uptake in humans was investigated in two volunteers. Simultaneous oral administration of 10 g of calcium alginate, 3 g of ferrihexacyanoferrate (II) and 130 mg of potassium iodide 30 min before 131I administration caused an almost complete block of the 131I thyroid uptake in both subjects. This indicated that calcium alginate and ferrihexacyanoferrate (II) had no influence on the blocking effect of potassium iodide on 131I thyroid uptake. This finding is important because mixed antidote treatment is the recommended treatment in cases of accidental exposure to mixed fission products.

Regeneration of Hemoglobin in Rats Exposed to Low Ambient Temperature

Rats kept at low ambient temperature (5°C) for 20 days showed on the 2nd and the 5th day of exposure slightly lower hemoglobin values than the control animals kept at room temperature. The rate of ...