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The article presents a study on the changes in the activity of antioxidant enzymes and in the amount of reduced glutathione (GSH) in selected mouse organs, which were influenced by the administration of melatonin and zymosan. The researchers collected blood samples from the carotid artery. They also used the Statistica computer program 7.1 to conduct the statistical calculations of the data gathered during the experiments. They found that the ability of melatonin to improve the permeability of blood vessel walls allows the transport of serum proteins.

This study investigated the role of exogenous α-lipoic acid (ALA) in the inflammation caused by zymosan application. Seventy-two adult male white mice were divided into twelve groups: three control groups, three Zymosan groups, three ALA groups and three groups being the combination of Zymosan and ALA. In the experimental groups, the animals were decapitated after 3, 6 and 24 hours after the injection. The activity of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px) were determined in the brain, liver and kidneys of the mice. After the injection of Zymosan, it was found that the activity of SOD, CAT and GSH-Px in the brain, liver and kidneys of mice was significantly lower in all time periods. The administration of ALA resulted in an opposite effect, namely, it increased the activity of the enzymes studied in the selected organs of mice. The Zymosan and ALA combination significantly inhibited the decrease in the activity of the enzymes compared with the values obtained in the groups of animals which received Zymosan only. The results of our study, using the Zymosan-induced inflammation, clearly indicate that ALA is an anti-inflammatory agent.

One of the major classes of ionotropic glutamate receptors is the class of N-methyl-D-aspartate receptors (NMDARs). Receptor activation recruits, via calcium signal transduction mechanisms which play important roles in oxidative metabolism, mitochondrial free radical production and occurrence of other mitochondrial factors which potentially contribute to excitotoxicity and neuronal death. In the present study, the effects of stimulation of NMDARs by applying N-methyl-D-aspartic acid (NMDA) in the brain, liver, kidneys and pancreas on change of the activity of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSHPx) and in the amount of reduced glutathione (GSH) in blood, brain, liver and kidneys has been investigated. Statistically significant decrease of the activity of SOD, CAT and GSHPx and in the amount of reduced glutathione (GSH) was found in the examined organs after administration of NMDA, an agonist of NMDA receptors, demonstrating that NMDA administration compromises the antioxidant status in the investigated organs of the mouse.

The effect of acute exposure of intraperitoneal injection of kainic acid (KA) on the activity of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSHPx), amount of reduced glutathione (GSH) and content of ascorbic acid (ASC) has been studied in brain, liver and kidneys of male mice. Animals (n = 144) were treated KA with one dose, i.e. 12 mg/kg body weight or saline solution. The influence of KA on the tested parameters after 2, 4, 6 and 24 hours was estimated. After the injection of KA it has been found that the activity of SOD, GSHPx and CAT is very clearly reduced in the brain and to a lesser extent in liver and kidneys. Simultaneously a decrease in the activity of antioxidant enzymes in the brain, liver and kidneys was accompanied by a decrease of the amount of GSH and ASC. A decrease in the activity of SOD, CAT, GSHPx (after 2 and 4 h) and amount of GSH and ASC in the brain, liver and kidneys suggests that oxidative stress plays important role in the pathogenesis of KA in mice. The obtained results suggest that KA not only is toxic to the brain but also for the liver and kidneys of mice.

Karyometric analysis revealed a distinct diurnal rhythmicity of the nuclear volume of pars nervosa pituicytes in mice maintained on a 12 h light:dark schedule. Maximum nuclear volumes of pituicytes in both males and females were observed at 1800 o'clock while the minimum ones at 1200 o'clock. In addition, a distinct rhythm was observed in the amount of lipid vacuoles in the pituicytes of both sexes; they showed two peaks, a larger one at 1800 and a smaller one at 600 o'clock, as well as two minima at 1200 and 2400 o'clock.

Authors studied the effects of single, total doses of ultrasound energy (frequency: 24.6 kHz; intensity: 0.35 W/cm2) on the cytoplasmic RNA level in the neurons of preoptic nucleus (PON) in Rana temporaria L., in the annual cycle. The cosinor analysis revealed that the applied ultrasound energy caused significant changes in the cytoplasmic RNA content in the PON neurons in Rana temporaria L. in the annual cycle. This was expressed by an increase in rhythm amplitude, except for the females of the second experimental group. Simultaneously, the rhythm acrophase in the animals exposed to ultrasound energy was shifted to later months (i.e. to the hibernation period), as compared to the control animals, where the acrophase occurred in August in females and in September in males (i.e. in their active land life period). In the females of the first experimental group the ultrasounds induced a disappearance of rhythmic changes in the cytoplasmic RNA of the PON neurons in the annual cycle.

In 70 sexually mature male and femal Rana temporaria frogs captured in natural habitat, mean nuclear volumes for the cells of the pars ependymalis and pars parenchymalis of the organon vasculosum laminae terminalis (OVLT) were determined in seven characteristic stages in life. The mean nuclear volume for the cells of the pars ependymalis and pars parenchymalis of the OVLT showed distinct annual fluctuation. Maximum nuclear volume of the cells in both investigated parts of the OVLT were observed during the breeding period (Ist decade of April), and minimum volume of the nuclei of the pars ependymalis at the beginning of hibernation (IIIrd decade of October), and in the pars parenchymalis near the end of active life (Ist decade of September).

The karyometric analysis of the cells of the pineal gland and subcommissural organ in Rana temporaria L. was carried out under the influence of dehydration in the annual cycle. The dehydration stress was found to retard the activity of the pineal gland and at the same time to stimulate the activity of the subcommissural organ apart from the breeding period and the middle period of active life on land. The results showed that both the pineal gland and the subcommissural organ take part in the regulation of water balance in the species under study.

The effects of single doses (3 g/kg and 9 g/kg) of 35% ethanol, on the glutathione (GSH) contents of the blood, liver and kidneys of Rana temporaria L. were studied in the annual cycle. It was found that the single doses of ethanol generally caused a significant increase of GSH in the blood and liver of males and females of Rana temporaria L. in each period of the annual cycle as compared with the control values. In time, it was found that the same doses of ethanol caused a significant decrease in the GSH content of the kidneys of the male and female Rana temporaria L. during their active land life and a strong increase of this tripeptide during hibernation.

Intraperitoneal injections of mercuric acetate or lead acetate in doses of 0.2 mg daily during 14 and 21 days caused statistically significant rise in the number of the Gomori-positive glial cells around the third cerebral ventricle of mice. In addition, the nuclei of the Gomori-positive glial cells markedly increased in volume.

By the use of Mac Conaill's lead hematoxylin, periodic acid and Schiff's reagent (PAS, PbH-positive and PAS-positive cells were distinguished in the pars intermedia of the hypophysis in mice. Nuclear volume in PbH-positive and PAS-positive cells in the pars intermedia of the hypophysis in male and female mice under conditions of 12 h light and 12 h darkness shows distinct diurnal rhythmicity. Maximum nuclear volume in PbH-positive cells of the pars intermedia in both sexes was observed at 1800 h, and minimum at 2400 h. In the Pas-positive cells in females maximum nuclear volume was observed at 600 h, and minimum at 2400 h. In males maximal nuclear volume in these cells appears at 2400 h, and minimum at 1800 h. Maximum number of vacuoles in the nuclei of PbH-positive cells in the pars intermedia in both sexes appeared at 1800 h, and minimum at 2400 h. Maximum numbers of vacuoles in the nuclei of PAS-positive cells in females was noted at 1200 h, and minimum at 2400 h. In males the maximum number of vacuoles appeared at 600 h, and minimum at 1200 h. Differences in the number of vacuoles in the nuclei of PAS-positive cells between males and females were also noted.

The influence of a single dose of ACTH(100 I.U. /kg body weight) on the diurnal rhythm of reduced glutathione (GSH) was studied in the blood and brain, liver and kidney homogenates of male mice. Cosinor analysis revealed that ACTH induces changes in the mean diurnal amount of GSH in the blood, brain, liver and kidneys. At the same time, GSH amplitudes in the blood and kidneys increased significantly, whereas in the case of brain and liver they decreased markedly. Moreover, it was found that ACTH induces a shift in GSH acrophases in the blood, brain, liver and kidneys as compared with the control values.

The changes in volume of neurocyte nuclei of the subfornical organ (SFO) of Rana temporaria L. under the influence of dehydration were analyzed in the annual cycle. Dehydration conspicuously influenced the activity of the neurocytes of the SFO during the year, depending on the stage of active life on land. It is suggested that in the amphibian under study, SFO participates in the regulation of water balance.

The influence of a single dose of actinomycin-D (1 mg/kg body weight) on the diurnal rhythm of cytoplasmic RNA was studied in neurocytes of the supraoptic nucleus (SON), paraventricular nucleus (PVN), and arcuate nucleus (AN) by microspectrophotometer. Cosinor analysis of the obtained results revealed a disturbed diurnal rhythm of cytoplasmic RNA in the animals treated with actinomycin-D. The mean diurnal RNA content in the SON, PVN, and AN neurocytes decreased, the amplitude of diurnal fluctuation was reduced and the acrophase was shifted to earlier hours.

The number of neurocytes containing lipofuscin pigment (LEP) was determined in the nucleus infundibularis dorsalis (NID), the subfornical organ (SFO) and the medulla oblongata (MO) of the brain of sexually mature females and males of Rana temporaria L. approximately identical in length and age. The frogs were captured in their natural habitat in seven periods of the annual cycle. The number of LFP-positive neurocytes shows distinct seasonal variations in the analyzed areas. In general, neurocytes containing LFP were found in higher numbers during the winter months, and their significant drop was observed in summer. The results seem to suggest that cells containing LFP represent a certain kind of dynamic cellular system responding to various internal and/or external factors changing within a year.

In sexually mature female and male Rana esculenta L. frogs directly from natural habitat, in six characteristic periods of their life cycle, nuclear volume in Purkinje cells of the cerebellum was determined. Nuclear volume in Purkinje cells changed distinctly in the course of the year. Nuclear volume was greatest in females in the breeding period (3rd decade of May), and in males in the middle of the period of active life (2nd decade of July). Nuclear volume was the smallest at the beginning of hibernation (3rd decade of October).

Sexually mature Rana temporaria L. frogs were captured in their natural habitat in seven stages of the the annual cycle. The volume of the nuclei of neurocytes of the pars dorsalis of the tuber cinereum containing lipofuscin pigment underwent significant changes in the course of the year. In both sexes the nuclear volume of the neurocytes was greatest in the terminal stage of winter sleep (1st decade of March), and smallest at the beginning of active life (3rd decade of May). The accumulation of lipofiscin pigment varied parallel to the changes in mean volume of the neurocyte nuclei of the pars dorsalis of the tuber cinereum.

Volume of the cell nuclei of the ependyma of the infundibular recess was measured in 30 female and 30 male water frogs (Rana esculenta L.) obtained from their natural environment, taking into account the phase of the annual cycle. Karyometry of the ependymal cell nuclei in the infundibular recess in males and females showed statistically significant differences of volume (activity) in the annual cycle. The largest volume of nuclei of the ependymal cells in females and males was observed in the first decade of April (end of hibernation), and the smallest in the first decade of September (end of the period of active life). Activity of nuclei of cells from the infundibular recess clearly correlated with gonadal development.

Sexually mature male and female Rana temporaria L. of similar body length were captured in their natural habitat in seven stages of the annual cycle. Each stage included one control and two experimental groups of frogs exposed to dehydration. Measurements of cytoplasmic RNA in the neurocytes of the preoptic nucleus (PON) were done by a microspectrophotometer. Analysis of the obtained results based on the cosinor procedure revealed that the dehydration caused a decrease in mean annual content of cytoplasmic RNA in the PON neurocytes in females and an insignificant increase in males. At the same time, amplitudes were markedly lowered, whereas rhythm acrophase in dehydrated animals were shifted to earlier months, as compared with findings in both sexes of the control group. The only exception were females of the second experimental group where the dehydration stress induced a disappearance of rhythmic variations of cytoplasmic RNA in the annual cycle.