Tag Archives: cholesterol

Long-term hypocholesterolemic effect of amidated alginate in rats

M. Marounek1, Z. Volek1, T. Taubner1, D. Dušková1, L. Kalachniuk2

1Institute of Animal Science, Prague, Czech Republic;
e-mail: marounek.milan@vuzv.cz;
2National University of Life and Environmental Sciences of Ukraine, Kyiv;
e-mail: kalachnyuk_liliya@nubip.edu.ua; lilkalachnyuk@gmail.com

The effect of octadecylamide of alginic acid on blood serum and hepatic cholesterol, and the faecal output of fat and sterols was examined in female rats fed diets containing cholesterol and palm fat at 10 and 50 g/kg, respectively for 10 weeks. Amidated alginate, supplied at 10 and 20 g/kg, significantly decreased serum cholesterol from 5.25 to 2.99 and 2.39 µmol/ml, respectively, and decreased hepatic cholesterol from 30.7 to 12.3 and 9.4 µmol/g, respectively. Amidated alginate increased the faecal output of fat and at higher dosing significantly decreased faecal output of bile acids. Faecal output of bile acids and hepatic cholesterol significantly correlated (r = 0.791; P < 0.001). The results of the present experiment showed that hypocholesterolemic effect of amidated alginate persisted within 10 weeks of feeding.

Preventive effect of N-stearoylethanolamine on memory disorders, blood and brain biochemical parameters in rats with experimental scopolamine-induced cognitive impairment

T. M. Horid’ko1, H. V. Kosiakova1, A. G. Berdyshev1, O. F. Meged1,
O. V. Onopchenko1, V. M. Klimashevsky1, О. S. Tkachenko1, V. R. Bazylianska1,
V. O. Kholin2, K. O. Peschana2, S. A. Mykhalskiy2, N. M. Hula1

1Palladin Institute of Biochemistry, National Academy of Sciences of Ukraine, Kyiv;
2Institute of Gerontology, National Academy of Medical Sciences of Ukraine, Kyiv;
e-mail: TanGoRi@ukr.net

The impairment of cognitive functions is the most studied medical and social problem nowadays. The aim of this study was to evaluate the protective effects of N-stearoylethanolamine (NSE) on memory state, blood and brain biochemical parameters in rats under scopolamine-induced cognitive impairment. The results of this study shown that NSE administration to rats per os (5 mg/kg, 5 days, during last 3 days NSE was administrated 20 min prior to scopolamine injection (1 mg/kg, once daily for 3 days, intraperitoneally)) prevented the development of memory impairment. In particular, NSE action was associated with the prevention of increase in acetylcholinesterase activity, changes in phospholipid, free and esterified cholesterol level in hippocampus and frontal cortex, and disruption in pro-/antioxidant balance in blood and studied brain sections. Considering the above mentioned biological effects, NSE is a promising drug candidate for integrative therapy of cognitive impairment of different profiles.

Exocytotic steps in cell-free system after cholesterol deprivation in synaptosomal plasma membranes and synaptic vesicles

V. P. Gumenyuk, I. O. Trikash

Palladin Institute of Biochemistry, National Academy
of Sciences of Ukraine, Kyiv;
e-mail: trikash@biochem.kiev.ua

Using a cell-free system we investigated a specific role of cholesterol in exocytotic processes. To modulate the cholesterol content in membrane methyl-β-cyclodextrin was used as a cholesterol binding agent. The experimental conditions for cholesterol depletion from synaptosomal membrane structures were determined and depended on methyl-β-cyclodextrin concentration, time and mediums temperature. The role of cholesterol was studied on the stages of synaptic vesicles docking and Ca2+-stimulated fusion which are the components of multivesicular compound exocytosis. Using­ dynamic light scattering technique we have found that after cholesterol depletion from synaptic vesicles the process of their aggregation (docking) remains unchanged.
It was found that the rate of calcium-triggered fusion of synaptic vesicles depends on the membrane level of cholesterol. The decreasing level of synaptosomal plasma membrane cholesterol by 8% leads to suppression of the Ca2+-dependent membrane fusion with synaptic vesicles. But, under 25% reduction of plasma membrane cholesterol the level­ of membrane merging with synaptic vesicles did not differ from control; probably this is due to changes in physical properties of lipid bilayer and/or disturbances in function of membrane proteins driving this process.
In cholesterol depleted synaptosomes the exocytotic release of glutamate stimulated by calcium was decreased by 32%. Obtained data suggest that the cholesterol concenration in synaptosomal plasma membranes or synaptic vesicles is the crucial determinant for synaptic transmission efficiency in nerve terminals.

Laureates of the Palladin Prize of the National Academy of Sciences of Ukraine (1991–1992)

V. M. Danilova, R. P. Vynogradova

Palladin Institute of Biochemistry, National Academy of Sciences of Ukraine, Kyiv;
e-mail: valdan@biochem.kiev.ua

The article presents biographical information and analysis of scientific activity of laureates of the Palladin Prize of NAS of Ukraine G. V. Donchenko (1991) and S. O. Kosterin (1992) who were awarded for the monographs “Biochemistry of ubiquinone” and “Calcium transport in smooth muscles”, respectively. These monographs summarized the results of the original researches and the data of the world scientific literature.