Phospholipid composition of human sperm and seminal plasma in relation to sperm fertility.

The phospholipid and fatty acid composition of sperm was studied in 8 healthy and 16 infertile men. Infertile men randomly formed from the patients with normal semen parameters according to WHO criterion. Therefore, all semen parameters of infertile patients were similar to the same characteristics of the semen of healthy men, except the abnormal forms. The amount of abnormal forms in infertile men was significantly higher than in healthy men. Sperm from infertile men show a drastic loss of phosphatidyl ethanolamine. At the same time, the significant increase of phosphatidyl serine in the sperm and seminal plasma of sterile patients was found. Lysophosphatidyl serine in the sperm of the infertile men was detected. Fatty acid composition of the semen of infertile men was altered. The levels of stearic and n-3 polyunsaturated fatty acids (eicosopentaenoic and docosahexaenoic acids) was dramatically lowered, but the values of some n-6 polyunsaturated fatty acids (linolenic and docosatetraenoic) acids increased. There was significant positive correlation between docosahexaenoic acid and sperm motility (r = .82, p < .001) and negative correlation between linolenic acid and spermatozoa motility (r = -0.58. p < .05). Infertility of men with normal semen quality can originate from the disorder of sperm lipid metabolism. The drastic loss of phosphatidyl ethanolamine and n-3 polyunsaturated fatty acids with simultaneous enhancement of phosphatidyl serine and some n-6 polyunsaturated fatty acids in sperm could be an important cause of male infertility.

Chernobyl clean-up workers erythrocyte membrane lipid content at the remote period.

Chernobyl Nuclear Power Plant accident clean-up workers were exposed to different radiation doses. Realization of remote effects depends on cellular membrane structure and function. We studied lipid composition of erythrocyte ghost and blood plasma in clean-up workers on the 12-th year after the accident. Groups of Chernobyl accident clean-up workers, non-irradiated patients with the same diseases and healthy controls were studied. Phospholipids were analyzed by two dimentional thin layer chromatography on silica gel. To analyse fatty acids and cholesterol gas chromatography was used. Total cholesterol and total phospholipids amounts in clean-up workers erythrocyte ghost were increased. The level of sphingomyelin and phosphatidylethanolamine raised. In some of the studied irradiated patients lysophosphatidylethanolamine appeared. The distribution of (diacyl)- and plasmalogen forms of phosphatidylcholine and phosphatidylethanolamine was not affected. The fatty acid composition changed slightly except 22:5 n-3, which level significantly increased and 22:5 n-6, which quantity lowered. The unsaturation index remains unchanged. No change in lipid composition of blood plasma was detected. All the changes in lipid composition of erythrocyte ghost of irradiated and unexposed patients were very similar. The obtained results confirm the suggestion about non-specific remote effects after exposure to low doses of ionizing irradiation.

Long-chain N-acylethanolamines inhibit lipid peroxidation in rat liver mitochondria under acute hypoxic hypoxia.

Two long-chain N-acylethanolamines (NAEs), N-palmitoyl- (NPE) and N-stearoylethanolamine (NSE), are shown to inhibit an in vitro non-enzymatic Fe(2+)-induced free radical oxidation of lipids in the liver mitochondria of rats with hypoxic hypoxia. NSE appeared to be more effective than NPE in suppressing some kinetic parameters of the Fe(2+)-induced chemiluminescence. The inhibitory action of NAEs on non-enzymatic lipid peroxidation supports the idea that they possess membrane protective properties.

The effect of long-chain N-acylethanolamines on some membrane-associated functions of neuroblastoma C1300 N18 cells.

As reported earlier (Gulaya, N.M., Vaskovsky, V.E., Vystosky, M.V., Volkov, G.L., Govseeva, N.N. and Artemenko, I.P. (1988) Ukr. Biochim. J. 60, 58-63), N-acylphosphatidylethanolamines (NAPE) and products of their catabolism, N-acylethanolamines (NAE), are present in the lipids of neuroblastoma C1300 N18 undifferentiated cells. The present paper describes the distribution of NAE added to culture medium of differentiated cells and its effect on the fast sodium channels and some other membrane characteristics. It is shown that NAE inhibits the destroying action of veratridine on membranes.

Modification of lipid composition of neuroblastoma C1300 N18 cells with liposomes alters the cholesterol content.

Cell incubation with lecithin-cholesterol liposomes (1:1 mol/mol) caused enhancement of the cholesterol content. The level of cholesterol esters of total and phospholipid unsaturated fatty acids increased in cholesterol enriched cells. Simultaneously the amount of saturated fatty acids decreased and lysophosphatidylcholine appeared in the cells. On the contrary, cell incubation with lecithin liposomes resulted in cholesterol depletion. This effect was accompanied by a decrease of cholesterol esters, of total and phospholipid unsaturated fatty acids. The content of saturated fatty acids was raised in cells with reduced amount of cholesterol. The quantity of N-acylphosphatidylethanolamine and N-acylethanolamine, lipids newly found in neuroblastoma cells, also changed in cells with modified content of cholesterol. The physiological role of cell response to the changes of cholesterol level is discussed.

Changes in lipid composition of neuroblastoma C1300 N18 cell during differentiation.

Phospholipids and cholesterol were found to be the main lipids in mature and immature neuroblastoma cells. The ratios for the total cholesterol/phospholipids in these undifferentiated and differentiated cells were 0.33 and 0.52, respectively. The ratios of 0.45 and 0.62 were obtained with corresponding plasma membrane fractions. Individual fatty acid contents in the loosely bound lipid fraction were higher than in tightly bound lipids. The total levels of saturated fatty acids increased in both of these fractions. While arachidonic acid content significantly decreased, it increased simultaneously (600%) in the free fatty acid fraction during differentiation. The amount of cholesterol esters increased three-fold as a result of maturation. For the first time it was possible to detect, in neuroblastoma cells, several lipids, namely N-acylphosphatidylethanolamine, N-acylethanolamine and semilysobisphosphatidic acid. They all changed during maturation. Total N-acylphosphatidylethanolamine content decreased by 50%, disappearing completely from membrane fractions. N-Acylethanolamine disappeared from the cell as well as from membrane fractions. On the other hand the total cellular content of semilysobisphosphatidic acid increased without any alterations in its membrane content. Functional implications of our investigations are discussed.