[Effect of pharmacological stimulation of melatonin receptors on renal function in aging.]

The aim of the study was to study ion exchange, as well as water and nitrogen excretion function of the kidneys in rats under the influence of pharmacological stimulation of melatonin receptors. The experiment was conducted on male rats, which were divided into 2 groups. The first group was a control group (n=35) and was kept in standard vivarium conditions. Animals of the second group received melatonin along with drinking water throughout their lives (n=35). The study was conducted in compliance with the international principles of the Helsinki Declaration on Humane Treatment of Animals. According to the blood and urine analysis, water consumption, the volume of diuresis, the content of creatinine, urea, sodium and potassium ions in urine and blood were determined. Based on the data obtained, the parameters of water-salt metabolism were calculated. The data obtained as a result of the study were subjected to statistical processing. As a result of the experiment, a decrease in the functional abilities of the kidneys was noted in rats both in the control group and in the group of animals treated with melatonin. However, data analysis shows that rats treated with melatonin had higher values of indicators of water-releasing, ion-regulating and nitrogen-releasing kidney functions compared with intact animals. Thus, long-term use of exogenous melatonin led to more stable functioning of the kidneys and water-salt metabolism in old animals compared with the control group.

[Prevalence of calcium deficiency in the hair in people at different age and sex living in the European North.]

Calcium is one of the most important elements in the human body, while its deficiency is common among residents throughout the world. The reasons for the deficiency are the lack of calcium in food and water, which is especially important for the North territories belonging to the biogeochemical provinces. The surface waters of the Republic of Karelia are ultra-fresh and low-mineralized. The purpose of this study was to determine the calcium level in the hair of the European North (Republic of Karelia) residents with an assessment of the deficiency prevalence in different sex and age groups. Atomic emission spectrometry and mass spectrometry with inductively coupled argon plasma were used for elemental analysis of hair. A 4-point scale corresponding to the range of deviation of the calcium content from reference values was used to estimate the data obtained. A Ca deficiency was established in 78,43% of individuals who participated in the study. The 4th degree of deviation from the norm towards a decrease in the concentration of the element in the hair was most often observed (43,15%). Calcium deficiency was equally typical for persons aged 20-25 years (84,45%) and 60-87 years (73,69%). It was more common in men (88,88%) than in women (72,73%), p<0,05. However, women were significantly more likely to be diagnosed with grade 4 calcium deficiency. From the foregoing, we can conclude that calcium deficiency in the Republic of Karelia is caused not only by age and gender characteristics, but it is connected with the natural, environmental and social conditions extent of the region. Residents of the North territories need an additional intake of calcium as part of mineral complexes, while the composition of such a complex should have a higher calcium content than for residents of central part of Russia.

[Hair macro- and microelement assessment in residents of European North depending on gender and age.]

This study investigated elemental status in people from Republic of Karelia to identify gender- and age-related differences and deviations from standard values typical for the central part of Russia. We used hair samples taken from the head occipital zone to determine amounts of twenty-five chemical elements. Four-point scale that corresponds to deviation range and reflects the difference from hair macro- and microelement referent values was used. The inhabitants of Karelia tended to be excessive in toxic elements and extremely low in many essential macro- and microelements. Fifty-seven people over 60 years old were diagnosed with excess in toxic elements of Hg and Pb and deficiency in essential elements of Ca, Zn, Fe, and P. Age-related differences for Si, Na, and K were also found. The imbalance for Co, Mg, I, Cu, Fe, Cr, and Se was similarly typical for both older examinees aged over 60 and younger people of 20-25 years old participated as a baseline group for comparison. That indicates the need to prevent region-related microelementosis in all social groups regardless of age. Men were commonly low in Mg and Na while I, Zn, P, and Cr deficits were more common in women. Karelia residents' microelement imbalance proved to differ from standard values depending upon gender and age which requires a personalized approach to the mineral insufficiency treatment.

Effect of Long-Term Light Deprivation on α-Tocopherol Content in Rats during Ontogeny.

We studied the effect of long-term light deprivation which began at different stages of ontogeny on the content of α-tocopherol in rats during the first 3 months of postnatal development. In the offspring postnatally exposed to constant darkness, the level of α-tocopherol in the liver, kidneys, heart, skeletal muscles, and lungs was significantly decreased at the early stages of postnatal ontogeny (2 weeks and 1 month). In rats kept under constant darkness after birth, the content of α-tocopherol in the lungs was also reduced at the age of 1 month. The modulating effect of light deprivation on the level of α-tocopherol can be associated both with the impact of disturbed circadian rhythms and with increased content of melatonin in the body.

[Research in possibility of rational use of antihistamines among elderly people from the perspective of safety and economic accessibility.]

The article is devoted to the research in possibility of rational use of antihistamines among elderly people taking into account Beers criteria and STOPP/START criteria which can prevent irrational use of medicines by senior consumers. Antihistamines that are not recommended for elderly people treatment were identified. Economic accessibility of antihistamines allowed for use among people aged 65 and over was evaluated.

[Absence of photoperiodism and digestive enzymes in rats: the role of the age and endogenous melatonin level.]

We studied the effect of prolonged absence of a photoperiodic signal (constant lighting and constant darkness) on the changes of digestive enzymes' activity in late postnatal ontogenesis of rats. Age-related alterations are characterized as a change in activity of enzymes, as well as a redistribution of the functional activity between the amylo- and lipolytic links, the upper and lower divisions of the gastrointestinal tract. It was shown that along with age, the activity of enzymes is affected both by the absence of photoperiodism and by the level of melatonin associated with the light regime. In conditions of light deprivation the age-related changes characterizing the «aging¼ of the digestive system are observed later compared with standard illumination and especially constant illumination.

[Element status of elder Petrozavodsk citizens.]

The purpose of this research was to estimate the element status of elder Petrozavodsk citizens and to compare them with the same characteristic of people living in the central part of Russia. The hair samples taken from people aged 60 and more were examined to study the content of 25 macro- and micro elements using the method of atom-emission and mass spectrometry with inductively bonded argon plasma. No misbalance was found in Al, As, Be, Ni and minor misbalance was found in Cd, Li, Sn, V. Toxic elements Hg and Pb and essential element B were found in hair samples in higher concentrations as compared to the referent values. Low concentrations in comparison with the referent values were found in Ca, Zn, Mg, I, Fe, P, Cu, Mn, Cr, Se, Si. The above-listed element status peculiarities can be associated both with old age and specific environmental, ecological and social aspects of living in the European North. Elemental misbalance detected can lead to endemic microelemetoses and health deterioration in elder Petrozavodsk citizens.

[Circadian rhythms of antioxidant enzyme's activity in young and adult rats under light deprivation conditions.]

We studied the age-related features of circadian rhythms of superoxide dismutase (SOD) and catalase activity in the liver of rats under light deprivation. In standard light conditions (LD), significant daily fluctuations in SOD activity with a maximum at 07:00 am was detected only in young animals (1,5 months) but catalase activity was observed in young (1,5 months) and in adults (7,5 months) with peak at 04:00 am. The daily dynamics of total and specific activity of SOD and catalase in the liver in young and adult rats differed depending on the period of ontogeny in which the impact of light deprivation began. When the females and offspring were moved to darkness after birth (group LD/DD), the circadian rhythms of SOD and catalase activitys were observed in young and were absent in adult rats. However, circadian rhythms of the antioxidant enzymes (AOE) activities were inherent only adult rats when light deprivation impacted on pregnant females (group DD/DD). Changes in circadian rhythms under light deprivation were characterized either by a phase shift of the enzymes activity (in the LD/DD group) or by a violation of their develpoment in ontogeny (in the DD/DD group). During aging significant decreasing of catalase activity was compensated by an increase in the amplitude of circadian rhythms of activity of this enzyme in animals of all groups. A distinctive feature of daily fluctuations in AOЕ activity in young rats in LD and LD/DD groups can be considered the presence of an ultradian rhythm in the general circadian cycle, which had a second peak with a smaller amplitude and shorter period.

[The role of constant light exposure in various periods of postnatal ontogenesis in the development of pathology and mortality in male rats.]

The purpose of the experimental work was to study the effect of constant light, depending on the time of the onset of light exposure (from the age of one month or from fourteen months), on the development of age-related pathology and oncology in male rats. The results of the study show that decreased functional activity of the epiphysis due to the influence of constant light from the age of one month increases the incidence of inflammatory, non-tumor and tumor genesis diseases, and leads to the rapid development of age-related pathology. On the contrary, the onset of constant light exposure in male rats from the age of 14 months slows the development of age-related pathology, reduces the incidence and development of malignant tumors.

[The influence of light deprivation and luzindol on ovulatory function of rats].

The age dynamics of ovulatory function of rats which were kept in conditions of light deprivation and receiving luzindol (a blocker the melatonin receptors) is investigated in this research. Cytological research of an estrous cycle was conducted quarterly within two years. It is defined that the age changes of an ovulatory cycle in the mode of light deprivation came later and were less expressed in comparison with similar changes at control rat females kept in the conditions of standard lightning. In case of the blockade of melatonin receptors by luzindol, the dynamics of aging of reproductive system corresponded to the one in the control group kept in standard lightning mode.

[The presence of anti-allergic antihistamines for consumers in older age groups].

The work investigated the availability of the antihistamines for consumers aged 45 years and older. The main factors reducing accessibility: self-healing, low frequency of references to the doctor if you have allergic reactions, failure to comply with medical appointments, low level of awareness about the use and side effects.

[Luzindol accelerates the aging of estrous function of female rats].

In this paper, we investigated the dynamics of aging of the estrous function of female rats kept in the conditions of standard vivarium lighting and receiving luzindol - the blocker of melatonin receptors. Every three months, daily, for two weeks, vaginal smears were taken from the animals and cytological examination of the vaginal contents was conducted. Despite different mechanisms of the development of melatonin system failure (a decreased production of melatonin and a blockade of melatonin receptors), the effects of the influence on the ovulatory function are similar. In case of the blockade of melatonin receptors, the appearance of premature signs of aging of the reproductive function in rats was observed. It was manifested by an increased duration of ovulatory cycle; a decrease in the number of regular cycles; the emergence of irregular cycles; a decrease in the number of short estrous cycles and an increase of long cycles; the early development of persistent estrus.

Effects of Geroprotectors on Age-Related Changes in Proteolytic Digestive Enzyme Activities at Different Lighting Conditions.

We studied the effect of melatonin and epithalon on age-related changes in proteolytic digestive enzyme activity in the pancreas and gastric mucosa of rats kept under different lighting conditions. In rats kept under standard illumination, pepsin activity and the total proteolytic activity in the stomach and pancreas increased by the age of 12 months, but then decreased. Constant and natural lighting disturbed the age dynamics of proteolytic digestive enzyme activity. Administration of melatonin and epithalon to animals exposed to constant lighting restored age dynamics of pepsin activity and little affected total proteolytic activity.

[Light pollution, desynchronosis and aging: the state of problem and solutions].

The effect of different light conditions (constant illumination, light deprivation, the standard regime of lighting and natural for Northwest Russia lighting in different seasons of the annual cycle) on indicators of biological age and homeostasis, the development of age-related pathology, oncogenesis and longevity of rats was investigated. Exposure to constant light on the studied parameters was evaluated at different ages--antenatal, early and late postnatal period. The data about influences of substances and hormones of pineal gland on biomarkers of aging, homeostasis, spontaneous oncogenesis and longevity in experimental animals was obtained. It has been established that the light pollution and disturbance of photoperiod lead to desynchronosys and as a result to premature aging of the organism and age associated diseases. Ways of preventing accelerated aging were outlined.

[Peculiarities of clinical picture of duodenal ulcer in the population of Northern Europe].

Duodenal ulcer remains a serious challenge to gastroenterology due to the difficulty of its management despite recent progress in this field. The role of melatonin in human body has attracted much attention of researchers in the recent years. Disturbances of its production are widely recognized to be involved in pathogenesis of duodenal ulcer and its exacerbation. This review summarizes results of research on the clinical picture of the disease in the population of European North where circadian and seasonal variations in melatonin production are most strongly pronounced.

[Light-induced disruption of the circadian clock and risk of malignant tumors in laboratory animals: state of the problem].

There were obtained sufficient experimental evidence of the stimulating effect on the development of tumors (transplanted, spontaneous and induced by various carcinogenic agents), disorders of circadian function of the pineal gland (light-induced desynchronosis) caused by knockout or mutation of clock genes, pinealectomy, content in conditions of constant light or natural light regime of the North, as well as jetlag modeling in laboratory rodents. In experiments on various models of carcinogenesis it was found that sympathectomy (removal of the superior cervical ganglion), light deprivation, hibernation and application of melatonin, the natural hormone of the pineal gland, had an inhibitory effect on the development of transplanted, spontaneous and induced tumors of different histogenesis.

[Protective effect of melatonin and epithalon on hypothalamic regulation of reproduction in female rats in its premature aging model and on estrous cycles in senescent animals in various lighting regimes].

Potential neuroprotective effects of the pineal gland hormone melatonin and peptide preparation epitalon on estrous cycles and the central regulation of reproduction in female rats exposed to unfavourable environmental factors have been studied. Estrous cycles of young, mature and aging rats exposed to light pollution were described. The diurnal dynamics and daily mean content of biogenic amines in the hypothalamic areas responsible for gonadotropin-releasing hormone synthesis and secretion in animals of different age groups were investigated. An effect of a chemical factor on the noradrenergic system of the medial preoptic area and on the dopaminergic system of the median eminence with arcuate nuclei of the hypothalamus was studied in premature aging of reproduction model. Administration of the pineal gland peptide melatonin and peptide preparation epitalon was shown to be able to correct a number of impairments of the hypothalamic-pituitary-gonadal axis that can be observed, when the experimental animals were exposed to permanent artificial lighting and a neurotoxic xenobiotic 1,2-dimethylhydrazine. The data obtained testify to an important role of the pineal gland in the circadian signal formation needed for gonadotropin-releasing hormone in order to exert its preovulatory peak secretion and to the protective effect of melatonin and epitalon, which are able to reduce unfavourable environmental influences on reproduction of young and aging female rats.

[The influence of constant lightening on physiological parameters of rats homeostasis depending on time beginning of exposure].

The influence of constant lightening on biomarkers of ageing and rates of male rats aging was studied. It was revealed that the maintenance of rats in the constant lightening regime starting from the age of one month results in accelerated ageing of the organism, the reduction of the phases progressive and stable growth, early occurrence of presenile and senile periods, to the earlier occurrence of water-and-salt metabolism imbalance, accelerate the process of "aging" of the antioxidant system in comparison with the rates of the control group. On the contrary, the maintenance of rats in the constant lightening regime starting from the age of fourteen months slows ageing of the organism, increases body growth, delays appearance of pathological changes in the urine, slows down the "aging" of the enzymatic components of the antioxidant system.

[Influence of the season of birth of male rats on some parameters of biological age].

The influence of the duration of daylight in the condition of natural lightning in the North-West part of Russia on the dynamics of parameters of biological age in male rats according to the season of birth had been studied during two years. It was found out that alteration of the duration of daylight regardless of the male rats season of birth modified rate of sexual maturation, growth, weight, food and water consumption, daily urine output and blood glucose compared with the analogous parameters in the condition of standard light and dark interchange.