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The paper presents the results of experimental instrumental studies of the psychophysiological features of regulatory properties of the nervous system under the influence of emergency factors. The investigations were made in the students of a navigation college before and after at least 6-month navigation on board the transport ship. Whether there is an association of adaptive behavioral responses with cardiac rhythm regulation under the influence of occupational activities was studied.

The authors evaluated vegetative homeostasis and higher nervous activities in individuals working with various wood antiseptics. The work with the antiseptics free of chlorphenols appears to increase parasympathetic activity; longer length of work with chlorphenol antiseptics activates sympathetic system. Contact with chemicals speeds up nervous processes and changes relationships between brain structures associated with decision making and motor activity regulation.

The authors report on creation of domestic chlorophenol-free preservatives for wood (EOK, K-12, Katan) in Arkhangelsk Research Institute. Application of those chemicals is cheaper than that of foreign analogs. Toxicity of the preservatives was evaluated according to morphologic and functional changes in various organs and systems of experimental animals which faced long exposure to the preservatives. The experiments proved K-12 to be the most pathogenic among others. EOK preservative fails to induce severe pathologic changes in experimental animals, demonstrated no cumulation and allergy. Katan takes intermediate place between those two.

The review is devoted to the main questions of investigations of the main index of carbohydrate metabolism--glucose in biological liquids of an organism. Detailed analysis of technological principles and interpretation of biochemical results with due regard to the influence of the complex of inner and external physico-chemical, biological and climatic factors is presented.

The effect of three exposures to Coriolis acceleration on the frequency and amplitude of fasting stomach contractions was investigated in 6 resistant and 16 susceptible to motion sickness test subjects. After tests all of them underwent gastroduodenoscopy and 4 subjects from each group were subjected to echography to measure gall bladder contractility in response to glucose-milk loads. After tests the motor activity of the stomach increased slightly in resistant subjects due to an increase of the amplitude and a slight decrease of biopotential frequency. During gastroscopy antral and pyloric sphincters were closed. In the stomach there was an insignificant amount of contents without gall. In the susceptible group, the motor activity was, on the contrary, inhibited due to a significant decline of the wave amplitude and frequency (by 40% and 11%, respectively). In the stomach, one or both sphincters were widely open; it also contained a large amount of gastric juice and gall. In 36% of susceptible and 17% resistant subjects, diaphragmatic hernia (at the esophageal opening) was found. Ultrasonic examination of the gall bladder showed that susceptible subjects developed its faster and stronger contraction when compared to resistant subject in response to glucose-milk loading. This pointed to a more prolonged duration of the gall excretion phase. Reactive changes of the gastroduodenal zone in response to motion tests facilitated duodenal-gastric reflux and major gastrointestinal symptoms of motion sickness.

The enzyme-excretory and motor functions of the gastrointestinal tract of rats flown for 18.5 days onboard the biosatellite Cosmos-1129 were studied. Immediately postflight, the pepsin synthesis decreased and the dipeptide parietal hydrolysis increased. At R + 6, the activity of the enzymes responsible for the cavitary and parietal hydrolysis of lipids significantly grew and that of the enzymes involved in protein hydrolysis fell. At R + 30, the carbohydrate hydrolysis was inhibited and the activity of lipolytic enzymes enhanced markedly. The amplitude and rhythm of stomach biopotentials were dysbalanced. The so-called immobilization stress of intact rats brought about activation of lipase, monoglyceridyl lipase, dipeptidase and inhibition of amylase and invertase. The immobilization exposure of flight rats caused inhibition of the membrane hydrolysis of proteins and carbohydrates and lack of the pancreatic reaction.

Carbohydrate hydrolysis, transport and utilization were investigated in rats exposed to diminished motor activity for 90 days. Glycemic curves were examined using provocative tests with equivalent quantities (1.5 g/kg body weight) of poly-, oligo- and monosaccharides (starch, maltose, glucose). Simultaneously, carbohydrases were measured in the homogenates of the pancreas, duodenal mucosa and small intestine as well as radioimmune insulin and glucagon were determined in blood. In the course of hypokinesia carbohydrate hydrolysis, transport and utilization varied in a different manner. At the beginning of exposure the activity of carbohydrases responsible for carbohydrate hydrolysis in the cavity and membranes increased which was accompanied by hyperglycemia and rapid utilization of carbohydrates. This is associated with nonspecific reactions to hypokinesia and higher requirements of the body for the energy substrate. By hypokinesia day 30 carbohydrate hydrolysis and transport were inhibited, hypoglycemia developed but glucose utilization remained unchanged. At a later stage of exposure the system of carbohydrate hydrolysis and transport showed an adaptive reaction; inhibition of pancreatic amylase was accompanied by accelerated enzyme transport in the small intestine and glucose resorption. In this situation the glycemic curves became extended suggesting a delay in glucose utilization. The latter was induced by changes in the endocrine compartment of the pancreas.

Full-value diets of similar composition were given to male rats weighing 207-230 g, by intravenous (group 1) or intragastric (group 2) routes. The proportion of amino acids, fats and carbohydrates was 9.9:15.7:74.4 (with regard to their calorific value). The diet calorific value comprised 60.6 kcal/rat/day. An average mass increase in group 1 was 2.44 +/- 0.14 g/day, in group 2 - 1.75 +/- 0.11 g/day. The protein content and activities of alpha- and gamma-amylase, invertase, maltase, and glycil-L-leucine dipeptidase were assayed in the intestinal mucosa of the proximal portion of the small intestine in group 1 rats, while a decreased alpha-amylase activity in the distal portion of the small intestine was recorded in the animals of group 2. The mass of the pancreas in the rats of group 1 and 2 was authentically lower than in the control rats which received oral feeding with natural foods. The lowest mass of the pancreas was observed in the rats of group 1. Specific activity of trypsin, lipase and RNase in the pancreatic tissues of rats in groups 1 and 2 was similar. The results of the study have evidenced a lowered function of the digestive system under conditions of artificial feeding, especially in case of intravenous nutrition.

In the crewmembers of four Salyut-6 long-term flights, enzyme excretory function of the gastro-intestinal tract was investigated. These studies included: gastric proenzyme, pepsinogen, and pancreatic enzymes, amylase and lipase, in blood and urine, trypsin in blood, intestinal enzymes, invertase and glycyl-L-leucine dipeptidase in feces, and lipids in feces. The results obtained demonstrated a correlation between changes in enzyme excretion and space flight duration and profile. After the 140- and 175-day flight the most marked changes in the digestive organs were seen; they manifested as a simultaneous increase in secretory function of the stomach and the pancreas. However, after the 185-day flight, in which advanced countermeasures were used, the above changes were less distinct.