[AGE AND SEX FEATURES OF BONE MINERAL DENSITY IN RATS].

In vivo assessment of bone mineral density (BMD) and bone mineral content (BMC) indices gives an objective description of the possible rates of bone loss during aging and various diseases, as well as response to treatment by various drugs, affecting bone metabolism. This study was conducted on 376 Wistar rats of both genders, divided into 12 age groups using the method of dual-energy X-ray absorptiometry. Studying the parameters of BMD and BMC depending on age and sex has found no bone mass opeak) in rats of both sexes. Bone mineral density indices were increased in both male and female rats during growing, more pronounced in males. These differences are noted in all age groups of animals. Moreover, we have established age and gender particularities of BMC indices in different parts of the skeleton. In female rats, a significant increase of BMD and BMC parameters have been detected in age from 1.5 to 2 months (33%), from 2 to 3 months - by 12.5%. In males, the increase of BMD indices was found to happen 1 month later and it was less pronounced (from 2 to 3 months - 27%, from 4 to 5 months - 5%). In other age periods, the dynamics of BMD indices had only an upward trend, but significant differences different groups were not established. Our results of BMD and BMC indices and their age and gender features can be used for further research in osteology as reference data for modeling of experimental osteoporosis in rats and study of response to the use of different antiosteoporotic drugs.

[Characteristics of heritability and effect of selection on prevalence of diffuse-toxic goiter in population].

On genealogic data about 242 Gravers disease patients, fertility parameters of 2105 healthy and 369 Grave's disease women peculiarities of genetic determination and natural selection of disease were studied. Results of the genetic analysis have revealed conformity of Grave's disease inheritance to alternative model parameters. Homozygote penetrance within the framework of this model was 78.8%, heterozygote--17.3%. For one generation in the Kharkov area population frequency of a gene to Grave's disease predisposition increases 0.8%.

[Effect of peptide regulators on the structural and functional status of bone tissue in ageing rats].

The wide spread of osteoporosis in women in the post-menopausal period stipulates the need for new effective means of prevention and correction of pathologic alterations in the bone tissue. Effect of two peptide bioregulators: cartilages preparation based on the cartilaginous tissue extract and T-31 substance on the mineral density of rat bone tissue has been studied in the experimental model of osteoporosis. The study has revealed an osteoprotective effect of both studied substances, with significantly higher efficacy of the preparation based on cartilaginous tissue extract. The substances exerted both prophylactic effect on the status of the cartilaginous tissue, preventing the decrease of mineral density of the bone tissue in rats after ovariectomy, and corrective effect by increasing the bone tissue density, which was reduced as a result of ovariectomy.

[Effect of thyroid hormones on calcitonin secretion]. / Vliianie tireoidnykh gormonov na sekretsiiu kal'tsitonina.

A study of 140 patients with diffuse toxic goiter showed phasic change in plasma calcitonin concentration and blood calcitonin activity: an increase in these indices at early stages of disease with a subsequent decrease in a severe form of thyrotoxicosis. Basal calcitonin secretion by fragments of the thyrotoxic thyroid was much higher than that euthyroid gland. In incubation of paranodal tissue of the thyroid of patients with nodular euthyroid goiter and fragments of the thyroid of patients with thyrotoxicosis of moderate severity with thyroxin at concentration 10(-8) M the level of calcitonin secretion considerably increased, concentration 10(-6) M was ineffective. The thyroid taken peroperatively from patients with diffuse toxic goiter with thyrotoxicosis of a severe form turned out nonreactive with relation to thyroxin concentration 10(-8) M. Basal calcitonin secretion in the study group was within control values. Thyroxin showed the properties of a calcitonin-secretion stimulator. Signs of depletion of the thyroid calcitonin-producing capacity were revealed in the course of development of diffuse toxic goiter.