[Peculiarities of the ovary structure in the rat offspring developing under conditions of the removed thyroid gland of female rat with the thyroxine replacement therapy and external radiation exposure in utero].

The influence of a single external gamma-radiation at a dose of 1.0 Gy (dose rate 9.08 x 10(-4) Gy/sec) on the 15th day of gestation in case of the removed complex of thyroid and parathyroid glands (thyroidparathyroidectomy) on the first day of gestation, as well as introduction of thyroxin and CaC12 on the structure of offspring ovary in postnatal ontogenesis (30-day old animals) was studied. It has been shown that thyroidparathyroidectomy of a female mother rat with thyroxine replacement therapy and irradiation, as well as the combination of these factors disturb the structure of ovarian tissues of the offspring. A single external irradiation on the 15th day of embryogenesis causes death of a considerable part of primordial follicles in the offspring ovary and growth of follicular layers in the secondary follicles. Thyroidparathyroidectomy of female rat on the first day of gestation with thyroxine replacement therapy causes delay in the development of follicles in the ovary at the early stages of maturation of 30-day old animals. The radiosensitivity of the ovarian tissues of the offspring that has been developed under the combined effect of the factors studied increases and results in an almost full loss of pool cells in the ovary of infant rats.

[The role of initial state of adrenal cortex in external irradiation effects upon its structure, function and androgen-receptor interactions].

We studied morphological-biochemical time-course reactions of adrenal cortex and hormonal function of testicles after combined or separate actions of external radiation exposure (1.0 Gy at 7.8 x 10(-4) Gy/sec) and prolonged (12-, 32 days) subcutaneous corticosterone injections (10 mg/kg/animal) in 2-3-month old male rats. Both variants with exogenous hormone depressed endogenous glucocorticoid production and evolved acute structure-functional adrenal gland cortex deficiency. Radiocensitivity of the gland at the experimental conditions was increased. Simultaneously the aggravation of adrenal cortex functional activity accompanied with hypogonadism and depressed reproductive potential of male rats, accessed by means of androgen status and androgenspecific (transporting and receptional) proteins characteristics as sensitive molecular markers of an animal possible fecundity.

[Development of rat embryos after prolonged irradiation of ovocytes at the stage of immature follicles]. / Razvitie zarodyshei krysy posle prolongirovannogo oblucheniia ovotsitov na stadii primordial'nykh follikulov.

It was shown that the prolonged low-dose irradiation (up to 0.6 Gy) of the immature ovocytes of young rats (21-28 days old) caused delay of development of preimplantation embryos after fertilization of ovicells.

[Changes in the adrenergic innervation of the large intestine in the postnatal ontogeny of the white rat]. / Izmeneniia adrenergicheskoi innervatsii tolstoi kishki v postnatal'nom ontogeneze beloi krysy.

Age-related changes of adrenergic structures in intramural (myenteric and submucosal) plexuses of the albino rats large intestine were studied in different stages of postnatal ontogenesis (5 days, 1,5,13 and 24-26 months). It was established that adrenergic link of innervation develops most rapidly during the first month of postnatal life. This results in decrease of adrenergic nerve fibres number and catecholamine content in them with the simultaneous hypertrophy of part of the structures. Speed of the destructive processes development in the intestinal nerve plexuses grows with age, which leads to greater reduction of the adrenergic structures number.

[Redox enzymes in the tissues of the large intestine in the postnatal ontogeny of rats]. / Okislitel'no-vosstanovitel'nye fermenty v tkaniakh tolstoi kishki v ontogeneze krys.

Using histochemical methods, age-related changes in activity of some redox enzymes in muscular and superficial layers of the mucous membrane, as well as in neurons of the myenteric nervous plexus of the large intestine have been studied in albino rats 5-day-old, 1-, 5-, 13-, 24-month-old. In young animals (1-5-month-old) an essential increase of the enzymatic activity of the energy metabolism takes place, in mature animals--stabilization of these processes, senescence brings about multidirectional changes in them. Manifestation degree of the changes in energy metabolism, occurring in old age are determined by certain metabolic and functional peculiarities in the organ tissue. In old animals certain strain of the energy metabolism develops, resulting from discoordination of energetic cycles in tissue of the large intestine wall.

[A histochemical analysis of the oxidative-reductive enzymes in the cardiomyocytes of mature and old rats following low-dose external gamma irradiation]. / Gistokhimicheskii analiz okislitel'no-vosstanovitel'nykh fermentov v kardiomiotsitakh zrelykh i starykh krys posle vneshnego gamma-oblucheniia v maloi doze.

The effect of gamma rays in low dose (0.5 Gy) on enzymes activity of glycolysis, tricarboxylic acid cycle, diaphorases in cardiomyocytes of adult and old albino rats at 3-, 10- and 30-day after irradiation was studied. It was established that the diaphorases activity decreased, the lactate dehydrogenase activity increased whereas that of other tricarboxylic acid cycle enzymes underwent phase changes. In result discoordination of redox enzymes in cardiomyocytes of rats hypoxic state develops. The question of the age sensitivity of heart to irradiation in low dose is discussed.

[Changes in the cell pool of the intramural neural plexus of the large intestine during postnatal development]. / Izmeneniia kletochnogo fonda intramural'nykh nervnykh spletenii tolstoi kishki na étapakh postnatal'nogo razvitiia.

Using a complex of morphological, morphometrical and histochemical methods, morphofunctional regularities for the age-related changes in the cell pool of intramural (myenteric and submucosal) nervous plexuses have been studied in the large intestine of albino rats during postnatal development. Three periods in development and differentiation of neurocellular resources of the intestine have been distinguished: progressive growth, relative stabilization and regressive phenomena. Peculiarities in structural-chemical transformation of cellular elements have been revealed during each period. Reduction of the cell pool of plexuses, as well as development of adaptive compensatory processes take place with ageing. The role of denervation of the organ in development of age-related functional disorders is discussed.

[The dynamics of the histochemical activity of the oxidoreductases in the myocardium of mature and old rats undergoing whole-body gamma irradiation at a dose of 1 Gy]. / Dinamika gistokhimicheskoi aktivnosti okislitel'no-vosstanovitel'nykh fermentov v miokarde zrelykh i starykh krys pri obshchem gamma-obluchenii v doze 1 Gr.

The effect of gamma radiation (1 Gy) on redox enzyme activity in heart cells of adult and old rats was studied during a month following the exposure. It was shown that the activity of diaphorases and succinate dehydrogenase decreased whereas that of other tricarboxylic acid cycle enzymes and lactate dehydrogenase underwent phase changes.