Intermittent normobaric hypoxia as a method of correction and prevention of functional changes in old age

The study involved men aged 60-65 years. The course of intermittent normobaric hypoxia (APG) was carried out for 3 weeks with breathing hypoxic gas mixture with 18-15-13-10% O2. Before and after the course, the reactivity of the cardiovascular system and blood system, physical performance were evaluated. It has been established that the course of APG increases oxidative metabolism, leads to a decrease in the level of sugar, total lipids and low-density lipids in the blood, an increase in the number of red blood cells, helps to reduce and stabilize blood pressure, increase physical performance of the elderly. The results of the study indicate the possibility of using APG as a method of correction and prevention of functional changes in the elderly. Key words: hypoxia, old age, blood, physical performance.

Effect of intermittent normobaric hypoxia exposure on acclimatization to high altitude by air induction

Background: In emergency like condition, defence personnel are deployed to high altitude without proper acclimatization. Maladaption at high altitude leads to high altitude illness like acute mountain sickness (AMS), high altitude pulmonary edema (HAPE) and high-altitude cerebral edema (HACE) which hampers the operational capabilities. Aims and Objectives: The aim of the present study was to assess the effect of intermittent normobaric hypoxia exposure (IHE) at sea level on different physiological responses during initial days of acclimatization at 3500m and 4000m altitudes in acute induction. Materials and Methods: The IHE subjects were exposed to 12% FIO2 (equivalent altitude 14500 ft) for 4 hrs/day for 4 consecutive days at sea level and 5th day they were inducted by air to 3500m altitude. Baseline recording of different physiological parameters like cardiovascular, respiratory, oxygen saturation and AMS score were measured at sea level as well as 3500m altitude on daily basis for 6 days to assess acclimatization status. To confirm acclimatization status at 3500m, on fifth day the IHE group subjects were transported by road to 4000m and again measured different basal physiological parameters (like cardiovascular, oxygen saturation and AMS score) for four consecutive days. Results: Different physiological parameters of IHE treated group were stabilized by day 4 of air induction at 3500m altitude. Whereas, at 4000m altitude, these parameters were stabilized by day 2 of induction. Conclusion: Acclimatization schedules of four days at 3500m and two days at 4000m are essential to avoid malacclimatization/or high-altitude illness.

Morphological differences in the pancreas of normo- and hypertensive rats after joint exposure of intermittent hypoxia and melatonin

The morphological changes in the pancreas of normo- and hypertensive rats after combined exposure to intermittent normobaric hypoxia and melatonin were studied. The study was conducted in the autumn on 24 normotensive (Wistar line) and 24 spontaneously hypertensive (SHR line) male rats. Experimental rats were daily exposed to hypoxic gas mixture in special sealed chamber. Hypoxic gas mixture (12 % oxygen in nitrogen) was supplied into this chamber from the membrane gas separator element in the intermittent mode: 15 min deoxygenation/ 15 min reoxygenation for 2 h. Exogenous melatonin was orally administered to experimental animals at 10 h in the morning at a dose of 5 mg / kg once a day. The total duration of the experiment was 28 d. Histological preparations of pancreatic tissue were prepared according to the standard methods. The morphometry of the preparations digital images was performed using the computer program ImageJ. The nature and severity of morphological changes in the pancreas of the experimental spontaneously hypertensive rats (hyperplasia of the nucleolus in the nucleus of exocrinocytes, a decrease in the amount of connective tissue) suggests that the combined effect of intermittent normobaric hypoxia and melatonin increases the activity of the exocrine part of the pancreas. At the same time, the activity of the endocrine part of the pancreas decreases, as evidenced by a decrease in the linear dimensions and area of the Langerhans islets, as well as the number of endocrinocytes contained in them. In Wistar rats, the combined effect of intermittent hypoxia and melatonin leads to the appearance of morphological signs of increased activity of both exocrine and endocrine pancreas functions. Thus, after prolonged combined exposure to intermittent normobaric hypoxia and melatonin, morphological signs of increased exocrine pancreas activity appear in both normotensive and hypertensive rats. At the same time, the activity of the endocrine function of the pancreas in experimental Wistar rats increases, while in SHR rats, on the contrary, decreases.

Влияние периодической нормобарической гипоксии на функциональные резервы организма крыс в свободном двигательном режиме и при антиортостатической гипокинезии

Введение. Снижение работоспособности и ортоустойчивости, наблюдаемых у космонавтов на разных этапах космического полета, диктует необходимость поиска новых методов, способствующих улучшению переносимости экстремальных факторов и восстановлению нарушенных функций организма, в реабилитационном периоде. Одним из перспективных направлений, повышающих общую неспецифическую резистентность организма являются гипоксические тренировки. Вместе с тем сведения о применении гипоксического воздействия непосредственно в условиях космического полета для нивелирования неблагоприятных эффектов невесомости отсутствует. Цель исследования - изучение влияния нормобарической периодической гипоксии на кардиореспираторные показатели и резервные возможности организма крыс при свободном двигательном режиме и в условиях антиортостатической гипокинезии (антиортостатическое вывешивание с углом наклона -30°), моделирующей физиологические эффекты невесомости. Методика. Проведено 4 серии экспериментов на 48 крысах Вистар, массой 280-300 г. Животные в течение 7 сут находились: в 1-й серии в свободном двигательном режиме с ежедневной 5-часовой нормобарической гипоксией (12% О2); во 2-й - в условиях антиортостатической гипокинезии после предварительного курса гипоксии; в 3-й - в антиортостатической гипокинезии без предварительной гипоксии (нормоксия 20,9% О2); в 4-й - в антиортостатической гипокинезии с ежедневной 5-часовой гипоксией. После завершения эксперимента у всех животных регистрировали кардиореспираторные показатели методом пневмотахографии, электрокардиографии, пульсоксиметрии, для оценки физической выносливости крыс использовали тест вынужденного плавания (по Порсолту). Результаты. Установлено, что эффективность НПГ в целях повышения функциональных резервов кардиореспираторной системы после длительного пребывания в условиях антиортостатической гипокинезии достигается только в результате предварительной адаптации (прекондиционирования) к периодической гипоксии в свободном двигательном режиме. Заключение. Воздействие нормобарической периодической гипоксии в условиях моделирования невесомости приводит к ухудшению функционального состояния организма и снижению физической выносливости крыс.Introduction. Restoring the physical condition of cosmonauts following a prolonged spaceflight requires new methods for improvement of resistance to extreme factors and recovery during the rehabilitation period. A promising approach to enhancing the general, nonspecific resistance to adverse environmental factors is hypoxic training. However, information about the use of hypoxia effects on the scene of a space flight to neutralize adverse effects of weightlessness is absent. Aim. To study the effect of intermittent normobaric hypoxia (INH) on cardiorespiratory parameters and reserve capacity of rats in free locomotion and in head-down tilt of -30°(HDT-30° ), a model of spaceflight. Methods. Experiments were performed on 48 Wistar rats weighing 280-300 g. For 7 days the animals were 1) in free locomotion with INH daily for 5-hours (12% O2); 2) in HDT-30o under normoxia following prior INH; 3) in HDT-30° under normoxia; 4) in HDT-30° in combination with INH. Cardiorespiratory parameters were recorded by pneumotachography, electrocardiography and pulse oximetry. Exercise tolerance was evaluated using the forced swimming test (Porsolt). Results. The effect of INH in increasing the cardiorespiratory functional reserve after long-term simulated microgravity is achieved only with prior adaptation (preconditioning) to INH in free locomotion. Conclusions. Intermittent normobaric hypoxia used in simulated microgravity leads to impairment of the functional state and decreases physical endurance of rats.

HEPATOPROTECTIVE EFFECT OF INTERMITTENT NORMOBARIC HYPOXIA UNDER THE RADIATION THERAPY OF THE RAT LIVER

Aim. To study the effect of intermittent normobaric hypoxia (INH) during local irradiation of the rat liver in therapeutic doses (total focal dose 30 Gy for 10 fractions) on the biochemical parameters of blood serum characterizing liver function. Materials and methods. Blood sampling in the animals of the control group and in three tested groups was performed prior to the experiment and following the experiment (after 20 days), respectively. The following criteria of hepatocyte toxicity were investigated: the level of the general and direct bilirubin, general cholesterol and triglycerides, high- and low-density lipoproteins, alanine aminotransferase and aspartate aminotransferase activity. Blood tests were performed using a Sapphire-400 (Tokyo Boeki ltd, Japan) automatic clinical analyzer with the standard Cormay (Poland) sets of reactants. Results. The experiment showed that the local radiation therapy on the liver region led to a growth in the indicators of pigment exchange, total cholesterol, low-density lipoproteins, triglycerides zdfl and transaminase activity. At the same time, the high-density lipoprotein level decreased. In the tested animals, INH application caused an increase in the bilirubin level and a change in lipid exchange indicators of the opposite direction in comparison with the animals receiving radiation therapy. INH did not change the transaminase activity. Liver radiation against the INH background led to less pronounced changes in blood biochemical indicators than in the group of animals having received exclusively radiation therapy. Such changes in blood indicators can be explained by a radioprotective effect of intermittent normobaric hypoxia. Conclusion. Intermittent normobaric hypoxia has a normalizing effect on the blood biochemical indices when performing local radiation therapy on the liver region.

Peculiarities of psychophysiological adaptation of marine cadets during professional training in marine specialities

Introduction.Occupational environment and occupational factors determine peculiarities in mastering marine occupations. Some unfavorable occupational educational and ecologic factors appear to cause high level of physical and psychoemotional stress.Objectiveis to study features of adaptation to study during occupational training in marine specialties in cadets of a higher marine educational institution, and to conduct medical and psychological rehabilitation.Material and methods.Examination covered 120 male cadets of 3rd and 4thyears of study: 70 (main group) and 50 (reference group). The age of the cadets was 21±0.4 years. To study characteristics of the cadets’ adaptation, the authors used psychological methods — Spielberger’s State Trait Anxiety Scale and Nemchin’s «Method measuring severity of neuropsychic stress». Statistical analysis was performed with software «Statistica for Windows 10.0».Study results and discussion.After 3 months of sailing, majority of the cadets appeared to be dysadapted. Deep clinical and laboratory studies proved that 39.4% of the examinees were apparently healthy and 60.6% of those had chronic diseases. Thus, a system of medical psychologic rehabilitation was designed, comprising primary and secondary prophylaxis methods. One of these prevention methods is a recovery complex of measures with intermittent normobaric hypoxia modified by us. The authors determined optimal regime of using intermittent normobaric hypoxia combined with medical rehabilitation.Conclusions.Adaptational state in cadets of high marine educational institution during professional training in marine occupations is characterized by increased psycho-emotional strain, anxiety and observed in 57.3% of the examinees. Findings are that after 3 months of sailing, majority of the cadets are dysadapted. To prevent morbidity and preserve health, the authors suggested a system of medical and psychologic rehabilitation including intermittent normobaric hypoxia with rehabilitation medical complex. The medical and prophylactic measures help to solve problems of psycho-emotional stress, lower morbidity parameters, prevent dysadaptation disorders, relieve functional overstrain. That preserves and improves the cadets’ health and forms an important stage in prevention of mental and behavioral disorders related to work.