Effect of Experimental Litter Reduction on Cerebellum Development in Suckling Rats.

We studied morphological features of the cerebellum in 14-day-old Wistar rats from reduced litters (the number of pups was reduced from 10-12 to 6 on the next day after birth). The control group comprised 14-day-old animals from litters of medium size (10-12 rat pups). Rats from reduced litters had greater body weight and brain weight.

Influence of Litter Reduction in the Neonatal Period at Different Times after Birth on the Parameters of Brain Development in Rats.

We studied the brain of 5- and 14-day-old intact (control group) rats and rats of the same age from litters experimentally reduced on days 1 and 5 after birth (experimental groups). In animals of both experimental subgroups, the brain had morphological signs of advanced development: greater weight of the brain and hemisphere, greater thickness of the cortex, its molecular layer, lower numerical density of neurons in the anterior parietal and proper parietal lobes, greater sizes of neurons, their nuclei, and nucleoli in the neocortex of these zones, and increased concentration of RNA in the cytoplasm of neurons. These data suggest that the rate of brain development in rats can be accelerated under the influence of environmental changes that occur after litter reduction during the neonatal period at different times after birth.

Effect of Experimental Litters Reduction during the Neonatal and Suckling? Periods of Ontogeny on Some Parameters of Brain Development in 30-Day-Old Rats.

We compared the effect of litter reduction on day 1 (series I) and day 14 after birth (series II) on the weight of the brain and right hemisphere and on the morphometric indicators of the development of the anteroparietal lobe in rats. Animals from both experimental series showed signs of acceleration (higher body weight and weights of the testes and ovaries). In series I, the weight of the brain and hemisphere and the thickness of the cortex surpassed the control values; the numerical density of neurons in layers II and V was lower and the numerical density of gliocytes was higher than in the control.

Dependence of Some Indicators of Brain Development in 30-Day-Old Rats on the Dynamics of Body Weight Gain in the Neonatal and Suckling Periods in Litters of Different Sizes.

We analyzed the dependence of the weight of the brain, its hemispheres, and morphometric parameters of the parietal cortex and the hippocampus in 30-day-old Wistar rats on their body weight at the age of 1, 7, 14, 21, and 30 days. All the animals were from medium-sized litters. In 6 litters (experiment), 6 rat pups were left in each litter 1 day after delivery; in 6 other litters (control), their number remained unchanged (8-13 pups).

Immediate and Delayed Effects of Food Restriction on Some Parameters of Brain Development in Rats.

The effects of 15-day restriction diet (from 1 to 1.5 months of age) on some parameters of brain development were studied in rats. The immediate and delayed (15 days after transfer to normal ration) effects were evaluated.

Formation of Hyaline Membranes in the Lungs of Albino Rat as a Result of Exposure to Bleomycin During the Neonatal Period.

We studied the effect of bleomycin (1 mg/kg) in 1-day-old rat pups (single intraperitoneal injection) and 4-day-old pups (3 injections on postnatal days 1, 2, and 3). The formation of hyaline membranes against the background of oxidative stress was documented in all bleomycin-treated rats. Repeated injection of bleomycin (4-day-old pups) led to more pronounced destructive alterations in the lungs characterized by the formation of microcysts and atelectases as well as hypertrophy of the interstitial connective tissue.

Effect of Antioxidant Echinochrome A on Bleomycin-Induced Pulmonary Fibrosis.

We studied the protective effect of antioxidant echinochrome A on bleomycin-induced pulmonary fibrosis in rats at the early stages of postnatal ontogeny. Administration of echinochrome A was shown to reduce the severity of bleomycin-induced oxidative stress in the lungs, prevented the development of hypertrophy of interalveolar connective tissue and peribronchial lymphoid infiltration, and normalized the ratio of volume densities of interalveolar septa and alveolar lumen.

3β-hydroxysteroid dehydrogenase in the brain ependymocytes.

We studied activity of 3β-hydroxysteroid dehydrogenase in rat brain ependymocytes. Enzyme activity was found in the cytoplasm of cells lining the villi in the vascular plexuses in the lateral ventricles and cells lining the ventricles. These data suggest that ependymocyte can synthesize neurosteroids.

[3beta-Hydroxysteroid dehydrogenase in ependimocytes of brain lateral ventricle lining and vascular plexus villi in rats of different age].

Using the histochemical method, the activity of 3beta-hydroxysteroid dehydrogenase (HSDH) was studied in the brain of laboratory male albino rats of different age groups: 5-6 days (n = 6), 45-50 days (n = 12), and 6 months (n = 15). The quantitative assessment of reaction intensity was performed with the cytospectrophotometer. The results obtained indicate that the ependimocytes lining the brain lateral ventricles and covering the villi of their vascular plexuses are characterized by the presence of HSDH activity typical to that of steroid-producing cells.

Morphometric and histochemical characteristics of the neocortex and hippocampus of experimentally enlarged rat brain during the suckling period of ontogeny.

Enlargement of the brain weight was attained in rats by reducing the number of neonates in the litter. The brain of 14- and 30-day-old animals was examined (controls: intact animals from litters of average numbers). Difference between the brain weight at 14 and 30 days was about 200 mg.

Effect of treatment with testosterone derivatives on morphometric characteristics and free radical oxidation in rat cerebral cortex.

Morphometric characteristics and free radical oxidation in neurons of the neocortex and hippocampus of male and female rats were studied 1 month after administration of Sustanon-250 in a dose of 8 mg/kg during the pubertal period of ontogeny. The weight of the brain was shown to decrease in males. In both female and male rats, the width of the anterior parietal lobe and the numerical density of neocortical and hippocampal neurons decreased.

Effect of gonadectomy on activity of neuronal 3β-hydroxysteroid dehydrogenase in some brain structures.

3β-Hydroxysteroid dehydrogenase is a key enzyme in the synthesis of steroid hormones in steroid-producing organs, including the brain producing neurosteroids. 3β-Hydroxysteroid dehydrogenase activity can be a marker of steroid-producing cells. We present the results of histochemical assay of this enzyme in the neocortex, hippocampus, and cerebellar cortex of gonadectomized prepubertal rats.

Histochemical detection of 3β-hydroxysteroid dehydrogenase in neurons of rat brain.

Here we present the results of histochemical detection of 3β-hydroxysteroid dehydrogenase in neurons of the neocortex, cerebellum, and brainstem. The positive reaction was observed in a low number of neocortical, midbrain, and pontine neurons. The maximum number of positive neurons was detected in the cerebellar cortex (Purkinje cells) and hippocampus.

Effects of infant rat fostering in artificially formed litters on the development of brain, adrenals and gonads.

Morphometric and histochemical properties of neurons in the frontoparietal and parietal lobes and CA1 hippocampal area, thickness of the neocortex, histochemical and morphometric properties of adrenals and gonads, and concentrations of sex hormones were compared in 40-day rats fostered in artificially formed (experimental group) and natural (control) litters. Animals of the experimental group had lower body and brain weight, thickness of the neocortex in the parietal lobe, sizes of nuclei and cytoplasm of layer 2 and layer 5 neurons of the frontoparietal and parietal lobes and in the hippocampus, lower NADPH-dehydrogenase activity in the hippocampus, and lower NADH- dehydrogenase activity in layer 2 neurons of the parietal lobe in comparison with control rats. RNA concentration in neuronal cytoplasm in neocortex and hippocampus was higher in rats from experimental group, than in animals from the control group.

Effect of long-term constant illumination of female rats on the parameters of brain development in their 40-day-old progeny.

We studied the progeny from female rats exposed to constant illumination for 1 month and mated with intact males 14 days after this exposure. At the age of 40 days, the progeny from experimental rats differed from the control by lower body weight, thickness of the adrenal cortex, and diameter of convoluted seminal tubules. The weight of the brain was similar in both groups.

Effect of experimental litter reduction in female rats on parameters of brain and endocrine gland development in the progeny.

We studied the relationship between parameters of brain development, elevated plus-maze behavior, and the status of the endocrine glands in the progeny of 4.5-5- and 8-9-month-old females after litter reduction by removal of one uterine tube. The progeny of young experimental females differed from the progeny of control animals by brain weight (at the age of 1 day), morphometrical characteristics of the cortex and its neurons, activity of 3beta-hydroxysteroid dehydrogenase in the adrenal cortex (at the age of 1 and 40 days), and behavioral reactions in the elevated plus-maze (at the age of 30 days).

Long-term consequences of prenatal exposure to lead on brain development in rats.

Administration of singe doses of lead citrate (200 mg/kg) to pregnant rats (on day 18 of pregnancy) was followed by the appearance of destructive changes in brains at age 40 days, with cysts, foci of gliocyte proliferation, pyknotic neurons, and decreases in NADH and NADPH diaphorase activities in neocortical and hippocampal neurons. Decreases in the density of neurons in the cortex and decreases in cortical thickness were also observed. The intensity of free-radical oxidation in the cortex increased three-fold, along with a 3.

[Remote consequences of prenatal exposure to lead on the brain development in rats].

Administration of a single dose of lead nitrate (200 mg/kg) to pregnant rats (Day 18 of gestation) resulted in the appearance of destructive brain changes in their offspring on postnatal Day 40, including the cysts, foci of glial cell proliferation, pyknosis of neurons, decrease of NADH- and NADPH-diaphorase activity in neocortical and hippocampal neurons. The reduction of both neuronal density in the cortex and cortical thickness was also demonstrated. The intensity of free radical oxidation in the cortex was increased 3-fold, while the concentration of lipid hydroperoxides was increased 3.

Morphometric and statistical analysis of macro- and microscopic characteristics of the brain and their relationships with adrenocortical histophysiology in newborn rats.

A direct relationship between the weights of the brain and hemisphere and parameters characterizing the development of the cortex and its neurons in intact newborn rats was revealed. Parameters of brain development in newborn rats correlate with 3beta-hydroxysteroid dehydrogenase activity in the adrenal zona glomerulosa.

[Peculiarities of ovarian and adrenal histophysiology in female rats producing the offspring with an accelerated brain development].

The purpose of the present study was to determine what peculiarities of endocrine and reproductive systems of female rats may favor the birth of the offspring with an accelerated brain development. The study included 20 female rats examined 1 day after the parturition and their 1-day-old offspring (n = 201). In females the activity of 3b-hydroxysteroid dehydrogenase (HSD) and lipid concentration were determined in ovarian steroid-producing structures and in all the zones of adrenal cortex.

Effect of administration of lead nitrate to pregnant rats on the lungs in their offspring.

Lead nitrate in a dose of 200 mg/kg was administered to female rats via a gartric tube on days 5 and 12 of pregnancy. The lungs of their offspring were examined on day 40 of life. We found a decrease in the ratio between the specific volumes of alveolar lumens and interalveolar septa and hypertrophy of lymphoid tissue in the bronchial wall (compared to the offspring of intact females).

Effect of the age of pregnant females on brain development in the offspring.

We examined offspring of 9-10 and 3.5-4 month-old female rats. Female offspring (14, 21, 28, 35, and 40 days) of old rats had higher body weight than offspring of young animals.

[A comparative morphological description of the gingival and buccal epithelium in females in various phases of the menstrual cycle].

Computer morphometry was used to analyze morphologically and histochemically the smears of the gingival and buccal epithelium obtained from women at the secretion and proliferation phases of the menstrual cycle. A variety of reliably statistic differences conditioned by a menstrual-cycle phase was found to be typical of the gingival epithelium. A high percentage of epitheliocytes of differentiation terminal stages as well as signs of enhanced protein-synthesizing processes were typical of the cells ratio in the gingival epithelium at the secretion phase.

Effect of testosterone derivatives administered to pregnant rats on the brain of their offspring (delayed consequences).

We examined the offspring of rats receiving sustanon with testosterone derivatives on day 19 of pregnancy. At the age of 1 month, these rats differed from control animals in the indexes of higher nervous activity. The relative weight of the brain increased in 54-day-old rats receiving the hormone.

[Morphological and cytochemical features of the gingival mucosal epithelium in women during different phases of the menstrual cycle].

Morphological analysis of smears of the gingival epithelium by computer-aided morphometry was carried out in women during the secretory and proliferation phases of the menstrual cycle. During the secretory phase the cell ratio was characterized by higher percentage of epitheliocytes in the terminal stages of differentiation. Size of the nuclei and cytoplasm of intermediate cells, concentration of total protein in them, number of the nucleolar organizer zones, and degree of bacterial contamination of epitheliocytes is higher during the secretory phase than during the proliferation phase.