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Biomedical subjects

L M Kurkina

Publications and source records attributed to L M Kurkina.

12 recordsLinked to original sources
PubMed1999

[The effects of space flights on the lipid composition of blood, adrenal glands and liver in rats].

Numerous postflight biochemical and morphological investigations of rats evidenced some shifts in lipid metabolism due to weightlessness and/or gravitation stresses. In the "Spacelab-2" experiment with rats, lipid spectra of blood serum (plasma), liver and adrenal glands were explored with the thin layer silicagel chromatography with the aim of evaluating stress effects of space flight on lipid metabolism. For the first time tissues were gathered and analyzed on day 13 in microgravity. Lipid composition of the liver remained unchanged after 13 days of flight. Those were cholesterol ethers of blood serum that were significantly increased while no changes had occurred in the relative quantities of each class of lipids in their totality. The adrenal glands considerably reduced concentrations of total lipids, free cholesterols, triglycerides, and free fatty acids. Within four hours into landing, free fatty acids were found to increase in blood plasma whereas the relative content of triglycerides decreased. Hepatic lipids remained unchanged and the adrenal ones did not differ from the control. On day 14 of recovery, the total content of blood plasma lipids was significantly increased on the score of triglycerides, and free and esterified cholesterols. The liver displayed decreases in all classes of fats; however, similar changes were in the control rats, too. The lipid composition of the adrenal did not differ from that of control. According to the total balance of lipids in rats' blood serum and liver, no signs of acute or chronic stress had been developed by the concluding stage of the 140-day space mission. Yet, one cannot exclude an acute stress early in mission that might have been the cause for the shifts in lipid metabolism in adrenals resulting in their reversible delipoidization.

Adrenal Glands↗
PubMed1980

[Metabolic indices in the central nervous system of rats during hypokinesia].

In rats placed into the small cylindric cages for 46--60 days, the RNA contents per 1 cell increased in neurons and glial cells of hypothalamic supraoptic nucleus, did not change in the nervous cells of the motor cortex, and decreased in the lumbar spinal cord cells. Concentrations of SH-groups in the motor cortex homogenate, GABA and treonine in cerebral hemispheres respectively decreased. The acetyl- and butyrilcholinesterase activity in the c. n. s. of control and experimental animals was the same.

Acetylcholinesterase↗
PubMedDate not supplied

[Protein fractions and their enzyme activity in rat myocardium after a 22-hour space flight].

No significant changes in the content of sarcoplasmatic and myofibrillar proteins were found in the myocardium of rats that made a 22-day flight onboard the biosatellite. On the 2nd and 26th postflight days the activity of aspartate and alanine aminotransferases of sarcoplasmatic proteins was increased and the total activity of lactate dehydrogenase and its isoenzyme spectrum remained unchanged. On the 2nd postflight day the ATPase activity of myosin of the myocardium was substantially lowered and on the 26th postflight day it returned to the normal. This decline in the ATPase activity of myosin can be regarded as an adaptive reaction to weightlessness.

Adenosine Triphosphatases↗
PubMedDate not supplied

[Changes in the soleus muscle tissue metabolism of rats after a flight on the Kosmos-690 biosatellite].

The soleus muscle of flown rats did not show any effect of gamma-irradiation on the composition and enzymic activity of protein fractions. On the Ist postflight day a significant decrease in the content of myofibrillar and sarcoplasmatic proteins in the soleus muscle was found. Besides, a drastic increase in the activity of aspartate aminotransferase and lactate dehydrogenase of sarcoplasmatic proteins and an atrophic type change in the LDH pattern were demonstrated. Those changes were similar to the weighttlessness-induced processes of atrophy and dystrophy and proved reversible.

Animals↗
PubMedDate not supplied

[Skeletal muscle mixed fiber tissue metabolism in rats after a flight on the Kosmos-690 biosatellite].

On the R+O day the quadriceps muscle of rats showed a decrease in the content of T protein and an inhibition of LDH activity of sacroplasmatic proteins. These changes resulted from the combined affect of space flight factors and gamma-irradiation, and may be considered as a decline of compensatory synthetic processes responsible for the recovery of muscle proteins in weightlessness. Inhibition of the age-associated shift of the M:H ratio of LDH found on the R+25 day can be attributed to the inhibitory effect of gamma-irradiation. No change in the content of glycogen in the gastrocnemius muscle of flight rats was noted.

Animals↗
PubMedDate not supplied

[Protein fractions and their enzyme activity in the rat myocardium in a Kosmos-936 biosatellite experiment].

The effect of artificial gravity on protein fractions and their enzyme activity in the myocardium of rats flown on board Cosmos-936 was studied. In weightless rats the content of sarcoplasmic proteins increased at R + O and that of T fraction proteins decreased at R + 25. In centrifuged rats such changes were not seen. In centrifuged rats the enzyme activity of sarcoplasmic proteins did not alter. In weightless rats ATPase activity of myosin decreased significantly, and in centrifuged rats it remained almost unchanged.

Adenosine Triphosphatases↗
PubMedDate not supplied

[Nitrous compound content in the tissues of the cerebral hemispheres and cerebellum of rats after a flight on the Kosmos-1129 biosatellite].

The content of ammonia, glutamine, urea, glutamic acid, aspartic acid, and GABA was measured to study nitrogen metabolism. Soon after recovery (6-10 hours after recovery) the content of the above compounds in brain tissues increased, except for GABA whose content decreased. Similar but more marked changes were seen in the brain of control rats exposed to a repeated immobilization stress-effect. These changes were still greater in the flight rats exposed to a repeated immobilization stress-effect postflight. It is suggested that the postflight changes of the above parameters of nitrogen metabolism are induced by stress-agents inherent in space flight and recovery.

Animals↗
PubMedDate not supplied

[Metabolic processes in rat skeletal muscle after a flight on the Kosmos-936 biosatellite].

The study of skeletal muscles of rats flown on Cosmos-936 demonstrated different metabolic reactions in muscle fibers of different function and type to weightlessness and Earth gravity. The data obtained gave evidence that artificial gravity may considerably prevent metabolic changes in muscles developing in response to specific effects of weightlessness.

Animals↗
PubMedDate not supplied

[Basic biochemical blood parameters in astronauts in preflight training].

From the findings of biochemical blood analyses obtained during original examinations of 24 cosmonauts with a repeat blood sampling (2-5 times) of each test subject there calculated the mean values of norm and the interval limits of norm using 33 biochemical blood indices for a given group of test subjects. It is shown that in the absence of significant discrepancies from the generally used mean population standards for the cosmonauts it is typical of some specific differences from universally adopted standards of the parameters mainly related to energy metabolism.

Blood Chemical Analysis↗