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Biomedical subjects

M Kohout

Publications and source records attributed to M Kohout.

At least 37 records · Page 2Linked to original sources
PubMed1986

Effect of acute altitude hypoxia on fatty acid proportion in the plasma of rats of different ages.

Using gas chromatography, the authors studied the development of the proportion of 25 saturated and non-saturated fatty acids in the plasma of Wistar rats of their own breed aged 5, 10, 14 and 25 days and adult (both sexes), and in three age groups (5 and 14 day and adult) they determined the effect of acute altitude hypoxia. Fatty acids were determined as methylesters (FAME) (Base 1978), using the method already described by Smídová et al. (1984a), in mixed blood plasma obtained from decapitated control and experimental animals. Altitude hypoxia, which corresponded to 9 000 m, lasted 20 min. The temperature was kept stable at 25 degrees C. Marked changes occurred during ontogenesis in the proportion of total fatty acids (TFA) in the plasma; the proportion of sigma non-saturated FA fell significantly during maturation, chiefly in favour of monoene FA, with a resultant significant drop in their reciprocal index (sigma saturated/sigma monoene). The proportion of all saturated FA amounted in 5-day-old rats to 54% of the total quantity, but in adult rats to only 40%. Acute hypoxia had a demonstrable effect in all three age categories. In 5-day-old rats it led to significant changes in 7 FA and in adult rats in 10. In both 5-day-old and adult animals it produced an increase in the arachidonic acid level. The results are discussed in relation to previous findings on the effect of the same hypoxia on FA proportion in various parts of the CNS of rats of different ages.

Aging↗
PubMed1985

Serum linoleic acid and cardiovascular death in postinfarction middle-aged men.

Linoleic acid in serum total lipids was the first variable in the stepwise regression analysis of metabolic, nutritional and cardiovascular factors in a secondary preventive study of postinfarction middle-aged men. It was followed in the regression analysis where the dependent variable was cardiovascular death by previous myocardial infarction, heart volume index and hyperlipoproteinaemia. Linoleic acid was the only fatty acid entering the regression. Unlike other fatty acids, it exhibited by its low percentage an accumulation of deaths. The decreased percentage of linoleic acid was also evident in the comparison of fatty acid patterns of cardiovascular deaths to age- and triglyceride-matched men free from ischaemic heart disease. This study confirms prospective associations found in previously healthy men. Conclusions are drawn about the relevance of low serum linoleic acid to long term prognosis after MI.

Cardiovascular Diseases↗
PubMed1982

Metabolic studies in postmyocardial infarction patients.

One hundred and seven patients registered in the secondary preventive programme in Prague 4 were followed up for an average period of 3 years. The endpoints of the study were taken as criteria of the progression of clinical atherosclerosis (non-fatal myocardial infarction, cardiovascular death). The authors tried to detect the causes responsible for the high prevalence of impaired glucose tolerance, diabetes and hyperlipoproteinaemia. They analyzed the interrelationships of food intake, insulin secretion, serum fatty acids and lipoprotein phenotypes. There were 6% of non-fatal myocardial reinfarctions and 13% of cardiovascular death after 3 years. Multiple regression analysis identified the following 3 factors closely associated with cardiovascular death: 1) history of myocardial infarction 2) low proportion of linoleic acid in total lipids 3) hyperlipoproteinaemia. The authors show that analysis of the relationships of triglycerides, insulin and serum fatty acids could be of value for identifying the factors involved in a faster progression of atherosclerosis.

Blood Glucose↗
PubMed1982

Metabolic turnover of fatty acids, cholesterol and lipoproteins in response to atherogenic factors in experimental atherosclerosis.

In experiments on two animal species we studied the effect of age, altered motor activity and alimentary experimental atherosclerosis on a variety of variables of lipid metabolism, particularly on cholesterol and fatty acid levels and formation. Fatty acid and cholesterol cumulation in tissues, including the rat aorta, increases with age (from 2 to about 20 months of age), while their formation decreases. A decrease of motor activity seems to be at play in this phenomenon in older animals and is apparently due especially to a faster rate of decrease of lipid degradation with ageing. Enforced increase of motor activity in rats (60 or 120-day adaptation on a treadmill - 18 m/min/3 hr/day) results in a decreased tissue cumulation of lipids including cholesterol despite their increased formation. In animals of the same age but allowed a limited amount of motor activity the situation produces reverse changes in lipid levels and formation. Changes in lipid metabolism are effected also by a higher level of spontaneous activity (induced by a higher number of young in the litter) and by increased motor activity of the dams during pregnancy. Hyperkinetic animals show a uniform exogenous (alimentary) cholesterol turnover. However their alimentary cholesterol absorption and high-density lipoprotein cholesterol turnover are elevated. Two respectively 10 months following the intake of 2% of dietary cholesterol minipigs exhibit elevated cholesterolaemia, reduced endogenous cholesterol synthesis in the liver and the aorta versus a decreased endogenous fatty acid synthesis. Plasma/vascular wall cholesterol transport in hypercholesterolaemic animals is about 50% higher, while the level of cholesterol in the medium remains constant. Most experimental animals show histologic evidence of incipient atheromatous changes not earlier than 10 months following the start of experimental diet.

Aging↗
PubMed1976

Blood flow and transport of free fatty acids in striated muscle under chronic ischemia.

Three weeks of ischemia of the right hind limb in rat produced by ligature and severing of the right common iliac artery, resulted in changes in FFA transport and blood flow in the regenerating tibialis muscle. FFA transport was measured using i.v. administered palmitate-1-14C bound to albumin. Uptake of palmitate-1-14C or 86Rb 90 s after i.v. administration was decreased in ischemic tibialis muscle, whereas no apparent effect of ischemia on the contralateral muscle was seen. Plasma FFA outflow rate measured according Beker and Rostami was not affected by the presence of an ischemic extremity in comparison with control animals. The plasma FFA inflow rate into the ischemic muscle was markedly decreased to values of 6.5 mmumoles FFA/min/g whereas in control animals values were 18.8 mmumoles FFA/min/g wet tissue. Decreased FFA inflow rate to the ischemic tibialis muscle was due to the decreased radioactivity of palmitate-1-14C in the muscle under the conditions of a constant plasma FFA pool. Differences in the uptake of palmitate-1-14C in tibialis muscle were dependent upon the muscle blood flow, which was markedly decreased in the ischemic muscle on indirect measurement with 86Rb or with the 133Xe clearance.

Animals↗