The Effects of Bioactive Compounds on Human Brain Structures and Diseases.

The human brain is the most intricate organ in the body [...

Sexual Dimorphism in Energy Metabolism of Wistar Rats Using Data Analysis.

The prevalence of some chronic diseases, such as cancer or neurodegenerative disorders, differs between sexes. Animal models provide an important tool to adopt potential therapies from preclinical studies to humans. Laboratory rats are the most popular animals in toxicology, neurobehavioral, or cancer research.

Melatonin mitigates hippocampal and cognitive impairments caused by prenatal irradiation.

Formation of new neurons and glial cells in the brain is taking place in mammals not only during prenatal embryogenesis but also during adult life. As an enhancer of oxidative stress, ionizing radiation represents a potent inhibitor of neurogenesis and gliogenesis in the brain. It is known that the pineal hormone melatonin is a potent free radical scavenger and counteracts inflammation and apoptosis in brain injuries.

Defining sex differences in selected lipid metabolites of blood plasma in Wistar rats.

There is an increasing attention to the role that sex/gender plays in health, behavior and outcomes. Even though we know that males and females are not the same, experiments have sometimes been carried out without considering sex in scientific research. It is essential for scientists and clinicians to consider sex differences as one of the underlying physiological determinants of health and disease to provide the building blocks for evidence-based, individualized medicine.

Neuronal analysis and behaviour in prenatally gamma-irradiated rats.

The intrauterinal development in mammals represents a very sensitive period of life in relation to many environmental factors, including ionizing radiation (IR). The developing nervous system is particularly vulnerable to IR, and the consequences of exposure are of importance because of its potential health risks. The aim of our work was to assess whether prenatal irradiation of rats on the 17th day of embryonic development with a dose of 1 Gy would affect the formation of new cells and the number of mature neurons in the hippocampus and the selected forms of behaviour in the postnatal period.

Ionizing radiation as preconditioning against transient cerebral ischemia in rats.

Induction of ischemic tolerance (IT), the ability of an organism to survive an otherwise lethal ischemia, is the most effective known approach to preventing postischemic damage. IT can be induced by exposing animals to a broad range of stimuli. In this study we tried to induce IT of brain neurons using ionizing radiation (IR).

Vitamin A and amygdala: functional and morphological consequences.

Intake of vitamin A is essential for correct embryonic development of the central nervous system (CNS). Its increased intake during gravidity can cause various malformations and dysfunctions of the CNS. In our work, we intended to investigate the effect of vitamin A on emotional behavior and morphology of nitrergic neurons in basolateral nucleus of the rat amygdala.

Effects of prenatal irradiation on behaviour and hippocampal neurogenesis in adult rats.

Prenatal irradiation is known to have aversive effects on the brain development, manifested in changes in some behavioural parameters in adult individuals. The aim of our work was to assess the effect of prenatal irradiation on different forms of behaviour and on hippocampal neurogenesis in rats. Pregnant female rats were irradiated with a dose of 1 Gy of gamma rays on the 16th day of gravidity.

Avoidance behaviour and anxiety in rats irradiated with a sublethal dose of gamma-rays.

The aim of this study was to assess, whether a sublethal dose of gamma-rays will influence the avoidance behaviour and anxiety in rats and whether the response to radiation depends on time of day of its application. Adult male Wistar rats were tested in elevated plus-maze, in hot plate test and in the light/dark box in 4 regular intervals during a day. After two weeks the animals were irradiated with a whole-body dose 6 Gy of gamma-rays.

Circadian rhythm of Z- and E-2-beta-D: -glucopyranosyloxy-4-methoxy cinnamic acids and herniarin in leaves of Matricaria chamomilla.

Chamomile (Matricaria chamomilla) in the above-ground organs synthesizes and accumulates (Z)- and (E)-2-beta-D: -glucopyranosyloxy-4-methoxy cinnamic acids (GMCA), the precursors of phytoanticipin herniarin (7-methoxycoumarin). The diurnal rhythmicity of the sum of GMCA (maximum before daybreak) and herniarin (acrophase at 10 h 21 min of circadian time) was observed under artificial lighting conditions LD 12:12. The acrophase is the time point of the maximum of the sinusoidal curve fitted to the experimental data.

Open field behavior and habituation in rats irradiated on the head with gamma-rays.

The goal of this work was to establish the effects of irradiation of the head with gamma-rays on selected forms of innate behavior, as well as on the habituation process to new environment in the open field test in rats. During a 5-day control period behavioral parameters reflecting motoric and explorative activities, as well as anxiety (6 parameters in total) were followed daily in 20 male Sprague-Dawley rats in an open field. Fourteen animals were repeatedly tested after irradiation of the head with a single dose of 10 Gy of gamma-rays.

Reduced pineal melatonin biosynthesis in fractionally irradiated rats.

The effects of ionizing radiation on pineal melatonin and on key enzymes of its metabolism have been studied in our laboratory. After adaptation to an artificial light/dark cycle of 12:12 h, male Wistar rats were fractionally whole-body irradiated with a dose of 2.4 Gy of gamma-rays twice a week up to total doses of 4.

Circadian oscillations of serum thyroid hormones in the laboratory rat: the effect of photoperiods.

The seasonal influence on circadian oscillations of serum thyroid hormones has been confirmed in the laboratory rat, an animal exhibiting low photoperiodic activity. The aim of this paper was to study the influence of various photoperiods, applied in a single season, on circadian variations in the levels of thyroid hormones in male Wistar rats. After 6-weeks of adaptation to artificial light-dark regimens (LD) 08:16 h, 12:12 h, 16:08 h, and to the standard housing conditions, the rats were examined in 3 h intervals in the course of 24 h in December.

The influence of melatonin on metabolic changes in female rats induced by continuous irradiation and/or administration of 7,12-dimethylbenz/a/anthracene.

Metabolic profile is an important biological marker of neoplastic processes not only in the tumor itself but also in the host organism. The neurohormone melatonin has been implicated in experiments as an oncostatic agent. Female Wistar:Han SPF rats (Velaz, Prague, Czech Republic) were irradiated continuously for 15 days using a daily gamma rays dose of 96 mGy.

Circadian and circaannual oscillations of tissue lipoperoxides in rats.

Circadian and circaannual oscillations of tissue lipid peroxides (LPO) were studied in young male Wistar rats. The concentration of malondialdehyde, one of LPO degradation products, was measured at 3-h intervals during 24 hours in rats, adapted to light:dark 12:12 h regimen in the course of the year. LPO in the liver, thymus and bone marrow oscillated rhythmically in the course of the day and year.

The effect of various photoperiods on daily oscillations of serum corticosterone and insulin in rats.

The effect of various photoperiods on circadian rhythms of chosen parameters was investigated in laboratory rats. SPF male Wistar rats were adapted for six weeks to artificial light-dark cycles (LD 8:16, 12:12, 16:8). The light was switched on at 07.

Influence of light regimen and time of year on circadian oscillations of insulin and corticosterone in rats.

Male SPF bred Wistar rats were adapted to natural light (N) and to a 12:12 h (light-dark) artificial light (A) regimen in the course of the year. The rats were analyzed at 3 h intervals during 24 h approximately at the time of the vernal and autumnal equinox and at the winter and summer solistice. Serum insulin circadian oscillations depended on the season, being different in various light regimens.

[Effect of neutron and gamma radiation on physical endurance of rats in the swimming test].

Three groups of adult male Wistar rats were exposed to neutrons (a single dose of 2 Gy) and gamma radiation (a continuous dose of 6 Gy delivered within 10.5 days) and a combination of both types of radiation. The physical fitness of irradiated and control rats was measured using a forced swimming test in the course and after the termination of the irradiation.

Influence of light regimen and the time of year on circadian oscillations of thyroid hormones in rats.

Male SPF rats (Wistar strain) were adapted in the course of the year to natural light (N) and to a 12:12 h (light:dark) artificial light (A) regimen. At approximately the spring and autumn equinox and the summer and winter solstice, rats were killed at 3-h intervals over a 24 h period and their serum thyroxine (T4), triiodothyronine (T3) and reverse T3 levels were determined. The light regimen and time of year significantly influenced the basic characteristics of the oscillations of the hormones.

The circadian and circa-annual response of rat serum corticosterone to different stressors.

The serum corticosterone (B) response to shortlasting immobilization and the administration of ACTH was studied during the year, at the beginning of the light and dark part of the day, in SPF Wistar rats of both sexes kept under standard conditions with a 12:12 h light and dark regimen. Both sexes reacted to the stressors (mainly immobilization) by a marked increase in B at the beginning of the light period. The maximum reaction, to both immobilization and ACTH, was found in males in the spring; females reacted more evenly throughout the year, with a maximum in the winter.

Circaseptan rhythm of corticosterone and lipids in the serum of male rats.

After adaptation to standard conditions and to a 12:12 h light: dark regimen, groups of young SPF male Wistar rats were killed at 8 h on 17 consecutive days and their serum corticosterone and lipid concentrations were determined. Using a combination of a Fourier harmonic analysis and an analysis of variance, the circaseptan rhythm of corticosterone, total cholesterol and triacylglycerol oscillations was determined; it is unlikely that the nonesterified fatty acid concentration has a 7-day rhythm. The circaseptan variation of metabolic and hormonal indicators is evidently adaptive in character and its existence ought to be taken particularly into account in the evaluation of long-term experiments.

Oscillations of serum and tissue lipids in rats X-irradiated at different times of day.

Young male Wistar rats (mean body mass 200 g) adapted to a 12: 12 h light: dark regimen (7 a.m.--7 p.

Circadian rhythm of serum and tissue lipids in the rat: the effect of limited access to food.

Young male Wistar rats of a conventional breed were kept 4 weeks in a separate room with a light: dark regimen of 12:12 h. Some were fed ad libitum (group C, the control), some were meal-fed from 8.30 to 10.

[Plasma and tissue lipids in rats after a flight on the Kosmos-1129 biosatellite].

Concentrations of triglycerides, total cholesterol, lipid phosphorus and nonesterified fatty acids were measured in blood plasma, liver, thymus, bone marrow and adipose tissues of rats flown for 18.5 days onboard the biosatellite Cosmos-1129. This exposure was accompanied by increases in lipomobilization, content of total cholesterol and lipid phosphorus in plasma, and triglycerides in the thymus and bone marrow.

Influence of the light regimen on the circadian rhythm of serum lipids in the laboratory rat.

Young male rats of a conventional Wistar breed were adapted for several weeks (3-6) to a 12:12 h light:dark (7 a.m. - 7 p.