strontium-radioisotopes and Body-Weight

The aim of our study was to define the biokinetics of (90)Sr after chronic contamination by ingestion using a juvenile and adult murine model. Animals ingested (90)Sr by drinking water containing 20 kBq l(-1) of (90)Sr. For the juvenile model, parents received (90)Sr before mating and their offspring were killed between birth and 20 weeks of ingestion. For the adult model, (90)Sr ingestion started at 9 weeks of age and they were killed after different ingestion periods up to 20 weeks. The body weight, food and water consumption of the animals were monitored on a weekly basis. Before killing and sampling of organs, animals were put in metabolic cages. (90)Sr in organs and excreta was determined by liquid scintillation β counting. Highest (90)Sr contents were found in bones and were generally higher in females than in males, and (90)Sr retention varied according to the skeletal sites. An accumulation of (90)Sr in the bones was observed over time for both models, with a plateau level at adult age for the juvenile model. The highest rate of (90)Sr accumulation in bones was observed in early life of offspring, i.e. before the age of 6 weeks. With the exception of the digestive tract, (90)Sr was below the detection limit in all other organs sampled. Overall, our results confirm that (90)Sr mainly accumulates in bones. Furthermore, our results indicate that there are gender- and age-dependent differences in the distribution of (90)Sr after low-dose chronic ingestion in the mouse model. These results provide the basis for future studies on possible non-cancerous effects during chronic, long-term exposure to (90)Sr through ingestion in a mouse model, especially on the immune and hematopoietic systems.

Topics: Aging; Animals; Body Weight; Drinking; Drinking Water; Female; Male; Mice; Models, Animal; Sex Characteristics; Strontium Radioisotopes; Time Factors; Water Pollutants, Radioactive

Cigarette smoking can influence the pulmonary disposition of other inhaled materials in humans and laboratory animals. This study was undertaken to investigate the influence of cigarette smoke exposures of rats on the pulmonary clearance of inhaled, relatively insoluble radioactive tracer particles. Following 13 weeks of whole-body exposure to air or mainstream cigarette smoke for 6 hr/day, 5 days/week at concentrations of 0, 100, or 250 mg total particulate matter (TPM)/m3, rats were acutely exposed pernasally to 85Sr-labeled fused aluminosilicate (85Sr-FAP) tracer particles, then air or smoke exposures were resumed. A separate group of rats was exposed to the 85Sr-FAP then serially euthanized through 6 months after exposure to confirm the relative insolubility of the tracer particles. We observed decreased tracer particle clearance from the lungs that was smoke concentration-dependent. By 180 days after exposure to the tracer aerosol, about 14, 20, and 40% of the initial activity of tracer was present in control, 100 mg TPM/m3, and 250 mg TPM/m3 groups, respectively. Body weight gains were less in smoke-exposed rats than in controls. Smoke exposure produced lung lesions which included increased numbers of pigmented alveolar macrophages distributed throughout the parenchyma and focal collections of enlarged alveolar macrophages with concomitant alveolar epithelial hyperplasia and neutrophilic alveolitis. The severity of the lesions increased with smoke exposure duration and concentration to include interstitial aggregates of pigmented macrophages and interstitial fibrosis. Our data confirm previous findings that exposure to cigarette smoke decreases the ability of the lungs to clear inhaled materials. We further demonstrate an exposure-concentration related magnitude of effect, suggesting that the cigarette smoke-exposed rat constitutes a useful model for studies of the effects of cigarette smoke on the disposition of inhaled particles.

Topics: Administration, Oral; Animals; Body Weight; Female; Lung; Lung Diseases; Male; Rats; Rats, Inbred F344; Strontium; Strontium Radioisotopes; Time Factors; Tissue Distribution; Tobacco Smoke Pollution

Female rats were kept on a diet with a low content of animal protein (5.5%) beginning from the 2nd day after delivery. Beginning from the 10th day after delivery their body weight was persistently lower than that of control females. Also the body weight of their young was lower than that of control animals throughout the experiment, with significant differences appearing on the 17th day of life. Spontaneous termination of maternal milk intake occurred in malnourished young 10 days later than in the controls. Retention of 85Sr in malnourished females was in keeping with their milk production. Irrespective of the differences in body weight and the quality of solid food, the malnourished young began consuming solid food at the same age and in the same relative amounts as the controls. Thus in malnourished young the period of gradual weaning was prolonged by more than to 3 weeks in contrast to 2 weeks in the controls. This is probably due to the slower extinction of the oral sucking mechanism resulting from changes in the maturation of the CNS. No changes were found in maternal behaviour (nest building and efficiency of retrieving) in malnourished females during the suckling period. However, infanticide appeared in some females during the weaning period.

Topics: Animals; Body Weight; Female; Lactation; Maternal Behavior; Pregnancy; Protein Deficiency; Rats; Strontium Radioisotopes; Weaning

Young laboratory rats received a daily subcutaneous injection of thyroxine (T4) and propylthiouracil (PTU) in saline, from birth until the period of spontaneous weaning. The rate of growth and the time of eye opening as well as the spontaneous weaning was assessed. The intake of maternal milk was followed directly, i.e. by the transport of 85Sr in maternal milk from the maternal body to the sucklings. In the young treated with T4 the eyes opened earlier than in the young treated with PTU. The body mass differed in both groups between the 4th and 20th day of life (the T4 pups were heavier). The 85Sr transfer in maternal milk was higher in the PTU young from the 22nd day of life. The PTU sucklings weaned spontaneously one week later than those receiving T4. A hypothesis has been proposed on the primary significance of maturation of oral mechanisms of sucking for spontaneous weaning.

Topics: Animal Population Groups; Animals; Animals, Suckling; Body Weight; Drinking; Female; Lactation; Milk; Ocular Physiological Phenomena; Pregnancy; Propylthiouracil; Rats; Rats, Inbred Strains; Strontium Radioisotopes; Thyroxine

Cartilaginous fetal bones from rat preserved by deep freezing procedures were compared to comparable fresh bones with regard to the following parameters: chemical composition, water and uronic acid contents; cell viability measured by the rate of proteoglycan synthesis; mineralization-ossification status by calcium binding; matrix integrity by the release of uronic acid containing substances; and biological activity as transplants inducing the formation of bone. The transplanted material was chemically analyzed and checked for its rate of proteoglycan synthesis. The quality of the formed bone was similar whether isogeneic or allogeneic, fresh or cryopreserved bone was employed as transplant material. Evidently those various fetal bones may be of clinical value whenever the need for replacement of massive bone loss arises. Although the viability and the cartilaginous nature of the graft are critical, the isogeneity and freshness are of a quantitative advantage only. These biochemical observations were confirmed by roentgenological and histological evaluations of the grafts. An optimal cryopreserving procedure and tests for examining bone candidates for successful grafting are described.

Topics: Animals; Body Weight; Bone and Bones; Bone Transplantation; Calcium Radioisotopes; Female; Fetus; Male; Osteogenesis; Pregnancy; Rats; Rats, Inbred BN; Rats, Inbred Lew; Strontium Radioisotopes; Tissue Preservation; Uronic Acids

Topics: Adipose Tissue; Animals; Body Weight; Calcium; Calcium Oxalate; Diphosphates; Kidney Calculi; Rats; Strontium; Strontium Radioisotopes; Technetium; Tissue Distribution; Vitamin B 6 Deficiency

The preliminary immunization with heated Proteus vulgaris culture introduced in a single injection was found to have a positive influence on the resistance of white mice to radiation emitted by incorporated 90Sr. This effect was manifested by an increase in the survival rate and the mean survival time of the animals, as well as by their increased physical endurance, and the stimulation of recovery process in the spleen.

Topics: Animals; Antibodies, Bacterial; Bacterial Vaccines; Body Weight; Bone and Bones; Female; Immunization; Male; Mice; Physical Endurance; Proteus vulgaris; Radiation Tolerance; Spleen; Strontium; Strontium Radioisotopes; Time Factors; Vaccination

Removal of the young for a single period of at least 12 hours at the age of 15 days led to a marked increase in 85Sr retention in the maternal organisms and to a decrease in its transfer to the young in the milk. Study of 85Sr transfer in the milk showed that, if the litter was completely changed on the 16th day after birth, the female immediately accepted foster young. Repeated removal of the young on the 14th day and 15th day of life for a length of time which had no effect in a single removal likewise led to a decrease in 85Sr transfer in the milk and to raise 85Sr retention in the female. The gradual decrease which occurs in lactation during the weaning period is probably caused by diminution of the suckling stimulus on the part of the young, as they lose their physical dependence on the female.

Topics: Animals; Animals, Newborn; Body Weight; Female; Lactation; Maternal Behavior; Milk; Pregnancy; Rats; Strontium Radioisotopes; Weaning

1. Total renal blood flow and its distribution within the renal cortex of the conscious rabbit were studied with radioactive microspheres of 15 and 25 mum diameter. 2. The reliability of the microsphere technique was influenced by microsphere diameter and number (dose). The optimum microsphere diameter for determination of flow distribution in the rabbit kidney was 15 mum and dose 100-150 000 spheres. 3. Spheres of 15 mum nominal diameter were randomly distributed within the renal cortex of adult rabbits. The larger spheres in batches nominally 15 mum in diameter in young rabbits and 25 mum diameter in adult rabbits were preferentially distributed to the superficial cortex. 4. In adult rabbits 15 mum diameter spheres lodged in glomerular capillaries. Larger spheres occasionally lodged in interlobular arteries causing intrarenal haemorrhage. 5. Microspheres of 15 mum caused a decrease in renal clearance of creatinine and of p-amino-hippurate when the total injection dose was about 200 000 spheres. These effects were greater when the injection dose was increased to 500 000 spheres. 6. The reduction in total renal blood flow observed with large doses of spheres largely reflected decreased outer cortical flow, as measured by a second injection of spheres, and confirmed by a decrease in p-aminohippurate extraction. 7. The reproducibility of multiple injection studies was limited by these intrarenal effects of microspheres. 8. Total renal blood flow measured in six rabbits in acute experiments by the microsphere technique was 107 plus or minus 12 (mean plus or minus SD) ml/min and by p-amino-hippurate clearance was 100 plus or minus 10 ml/min. 9. Total renal blood flow in twelve conscious, chronically instrumented rabbits was 125 plus or minus 11 ml/min, of which 92 plus or minus 6 ml/min was distributed to the superficial cortex and 33 plus or minus 4 ml/min to the deep cortex.

Topics: Animals; Body Weight; Catheterization; Chromium Radioisotopes; Glomerular Filtration Rate; Kidney; Kidney Cortex; Male; Microspheres; Organ Size; Rabbits; Regional Blood Flow; Scandium; Strontium Radioisotopes

Topics: Animals; Body Weight; Diuresis; Glomerular Filtration Rate; Hematocrit; Hemodynamics; Ischemia; Kidney; Kidney Cortex; Male; Microspheres; Rats; Regional Blood Flow; Strontium Radioisotopes; Time Factors; Ureteral Obstruction; Urine

Topics: Age Factors; Animals; Body Weight; Female; Growth; Milk; Rats; Strontium Radioisotopes; Time Factors; Weaning

Topics: Animals; Biomechanical Phenomena; Body Weight; Bony Callus; Collagen; Hindlimb; Hydroxyproline; Male; Mice; Organ Size; Phenytoin; Stimulation, Chemical; Strontium Radioisotopes; Tibial Fractures; Time Factors; Wound Healing

Topics: Animals; Body Weight; Bone and Bones; Bone Resorption; Calcitonin; Calcium; Drug Interactions; Estradiol; Male; Parathyroid Glands; Rats; Strontium Radioisotopes; Thyroid Gland; Thyroidectomy; Tibia