[Oxidative modification of blood plasma proteins in elderly people with vascular dementia]. / Okislitel'naia modifikatsiia belkov plazmy krovi u pozhilykh liudei s sosudistoi dementsiei.

We examined the spontaneous and metal-ion-catalyzed oxidative modification plasma blood proteins in the group of healthy adults and elderly ones and patients with vascular dementia (mild and severe). We determined the spectrophotometric measurement of 2,4-dinitrophenylhydrazone derivatives formed by reactions with protein carbonyls. The level of metal-ion-catalyzed oxidation proteins in the aged patients both with and without dementia was high in comparison to the healthy adults. The patients with severe dementia showed lower amount of 2,4-dinitrophenylhydrazone deriviates. Low levels of metal-ion-catalysed protein oxidation strongly correlated with the degree of psychoorganic disturbances. The elderly persons with both and without dementia showed a high level of plasma nonenzymatic H2O2 scavenging in comparison with the healthy adult ones. We discovered an imbalance between enzymatic and nonenzymatic components of the antioxidant system. The latter indicates that the oxidative modification of brain tissue proteins probably plays an important role in aging and mental disorders.

[Oxidative modification of blood proteins in patients with psychiatric disorders (depression, depersonalization)]. / Okislitel'naia modifikatsiia belkov plazmy krovi bol'nykh psikhicheskimi rasstroistvami (depressiia, depersonalizatsiia).

We determined the oxidative modification of proteins (spontaneous and metal-catalysing oxidation, MKO) and the level of corticosteroids in patients with the depersonalization and depression. For detecting oxidative modification of plasma proteins we measured the concentration of protein carbonyl groups formed with 2,4dinitrophenylhydrazine 2,4dinitrophenylhydrazone derivatives; the formation of dityrosine by fluorescence method; protein aggregation and fragmentation. Polyacrylamide gel electrophoresis with sodium dodecyl sulfate (SDS)-PAGE in the presence beta-mercaptoethanol was used to determine the aggregation or fragmentation of proteins by oxygen radicals (OH). Acid-soluble peptides were analised as products of the fragmentation oxidative modification proteins. The level of the corticosteroids was determined using HPLS. The increase of the concentration of protein carbonyl groups in blood plasma of patients with mental disorders. In patients with depersonalization we determined the increase of the bityrosyl cross-link, and different degrees of fragmentation compared with depressive patients. The cortisol level was decreased and corticosterone was increased in the blood plasma of patients with depersonalization. In depressive patients the cortisol level was increased and corticosterone was decreased is discussed. We discussed the role oxidative modification proteins in the disturbance of the corticosteroid and opioid receptors functions in the patients with mental disorders.

[An evaluation of the hypolipidemic effects of lovastatin in primary hypercholesterolemia. A multicenter study]. / Otsenka gipolipidemicheskikh éffektov lovastatina pri pervichnoi giperkholesterinemii. Mnogotsentrovoe issledovanie.

In the multicenter trial, the hypolipidemic efficacy and adverse event profile of lovastatin were estimated in 294 patients with primary hypercholesterolemia. The mean baseline (on placebo) lipid and lipoprotein values were: total serum cholesterol (TC) 313 mg/dl, triglycerides (TG) 168 mg/dl, low density lipoprotein cholesterol (LDL-C) 235 mg/dl, high density lipoprotein cholesterol (HDL-C) 44.9 mg/dl. Lovastatin was begun with 20 mg/day, the dose being doubled after 4 and 8 weeks if the target reduction of TC < 200 mg/dl was not reached at those moments. At the end of the treatment the mean TC decreased by 29.5% (p) as compared with the baseline level, TG by 14% (p). The normal target level of TC was reached in 106 patients (36%), the borderline levels (200-240 mg/dl) in 123 (42%), high TC (240 mg/dl) remained in 65 patients (22%). LDL-C decreased by 38% (p), HDL-C increased by 7.8% (p), whereas LDL-C/HDL-C ratio decreased by 40% (p). The treatment was well tolerated by patients: mild clinical side effects were noticed in 2.7% of patients and asymptomatic transient deviations of laboratory tests in 8.2%. The authors conclude about high hypolipidemic efficacy and low adverse event profile of lovastatin in patients with primary hypercholesterolemia.

[Isolation and properties of triglyceride lipase from the rabbit liver]. / Vydelenie i svoistva triglitseridlipazy pecheni krolika.

Using affinity chromatography on heparin-Sepharose 4B, triglyceride lipase was isolated from rabbit liver tissue and purified. The specific activity of the enzyme isolated from the usual homogenate was equal to (3.8 +/- 1.2) x 10(3) mumol/hour/mg protein. After treatment of liver tissue homogenates with liquid nitrogen the enzyme activity increased severalfold as compared to the enzyme isolated from the usual homogenate. The dependences of the triglyceride lipase activity on the concentrations of the protein (enzyme), substrate (triglyceride), albumin (fatty acid acceptor) and pH were studied. The isolated form of liver triglyceride lipase was found to have two pH optima at 6.5 and 8.5.

[Triglyceride lipase from the rabbit liver]. / Triglitseridlipaza pecheni krolika.

Unlike the rabbit blood plasma the high-activity triglyceride lipase which does not require a protein cofactor and is resistant to 1 M of NaCl has been revealed in the liver of this animal. Rapid freezing of the liver tissue by liquid nitrogen before homogenization induced a sharp increase in the enzyme activity level and extraction of the active enzyme without heparin usually added to the homogenate. The specific activity of hepatic lipase purified from the ordinary heparin-containing homogenate by affinity chromatography on heparin-sepharose 4B was equal to 3800 microM of FFA/h per mg of protein. If the homogenate previously treated with liquid nitrogen was used as a source of enzyme, the specific activity of hepatic lipase was higher, namely, 13,000 and 19,000 microM of FFA/h per mg of protein in the presence or absence of heparin, respectively.

[Inhibition of lipoprotein lipolysis by polyarginine and evaluation of the mechanism of its interaction with lipoprotein lipase]. / Ugnetenie poliargininom lipoproteidlipoliza i vyiasnenie mekhanizma ego vzaimodeistviia s lipoproteidlipazoi.

It was found that polyarginine (Mr 40 000-60 000) is a strong inhibitor of the lipoprotein lipase activity in vivo and in vitro. The inhibitory effect in vivo was observed after a single intravenous injection of 0.85-3.5 mg/kg to rabbits, that in vitro at the polypeptide concentration of greater than or equal to 2.5 micrograms/ml. Within the first few hours after intravenous injection of polyarginine hyperlipidemia occurred with an obvious increase in the plasma triglyceride and VLDL fractions and a slight decrease of the LDL and HDL fractions. These changes typical for reduced lipoprotein lipolysis were due to the formation of a polyarginine-heparin complex, on the one hand, and to the formation of a polyarginine-enzyme complex devoid of the lipolytic properties, on the other. The inhibitory effect of polyarginine on lipoprotein lipase is related to the whole polypeptide molecule or its large fragment, since arginine and metformine (bi-guanidine compound) have no effect on the enzyme activity.

[Comparison of the effect of homologous and heterologous albumin on the activity of lipoprotein lipase and liver triglyceride lipase in rabbit plasma]. / Sravnenie deistviia gomologichnogo i geterologichnogo al'bumina na aktivnost' lipoproteidlipazy i pechenochnoi triglitseridlipazy plazmy krovi krolika.

Changes in the activity of blood plasma lipoprotein lipase (EC 3.1.1.34, LPL and hepatic triacylglycerol lipase EC 3.1.1.3, H-TGL) were studied in rabbits injected intravenously by homologous and heterologous albumins (bovine, fraction Y, Sigma, BSA) alone and in combination with heparin. Rabbit albumin enhanced the effect of heparin on the LPL activity, while heterologous protein, to the contrary, diminished it. The in vitro experiments showed that BSA caused a more distinct effect on the LPL activity as compared with that of rabbit albumin. The activity of H-TGL was not significantly altered under the influence of both proteins.

[Effect of the intravenous administration of homologous albumin on the lipolytic enzyme activity of rabbit blood plasma]. / Vliianie vnutrivennogo vvedeniia gomologichnogo al'bumina na aktivnost' lipoliticheskikh fermentov plazmy krovi krolika.

Activity of main lipolytic enzymes of rabbit blood plasma, lipoprotein lipase (LPL) and liver tissue triglyceride lipase (L-TGL) as well as intensity of lipoprotein lipolysis in vivo, which was estimated by an increase of unesterified fatty acids in blood plasma, studied after intravenous administration of homologous albumin at a dose of 200 mg/kg of body mass. The data obtained suggest that albumin is involved in regulation of lipoprotein lipolysis due to activation of LPL, caused by asseption of unesterified fatty acids, which are liberated after hydrolysis of triglycerides. This effect was exhibited by albumin only under conditions of active stimulation of lipolytic reactions, it occurs after intravenous administration of heparin (100 IU/kg of body mass). Albumin did not activate lipoprotein lipolysis and lipolytic enzymes in intact animals. Activity of L-TGL in blood plasma was less distinctly subjected to the regulatory effect of albumin.

[Role of lipolytic enzymes in the development of hyperlipidemia induced by administration of heterologous albumin in rabbits]. / Uchastie lipoliticheskikh fermentov v razvitii giperlipidemii, vyzvannoi vvedeniem geterologichnogo al'bumina krolikam.

Experiments on rabbits have shown hyperlipidemia to develop within the first 48 h after a single intravenous injection of bovine serum albumin (BSA, fraction V). The mean concentration of blood plasma triglycerides (TG) was considerably higher than normal (by 262% after 24 and by 625% after 48 h). The cholesterol content was also elevated (by 80 and 270%, respectively). Following 7 and 14 days the lipid concentration returned to normal. The plasma post-heparin lipoprotein lipase activity (PHP-LPL) was lower 24 h and 7 days after BSA injection and the hypotriglyceridemic effect of heparin was less pronounced. The data obtained support the hypothesis that hyperlipidemia provoked by a single intravenous injection of BSA to rabbits results from low PHP-LPL activity and possible changes in TG-rich lipoprotein substrate affinity for the enzyme.

[Lipolytic activity in blood plasma of patients with ischemic heart disease after administration of heparin on an empty stomach and with simultaneous fatty loading]. / Lipoliticheskaia aktivnost' plazmy krovi bol'nykh ishemicheskoi bolezn'iu serdtsa pri vvedenii geparina natoshchak i na fone zhirovoi nagruzki.

Effect of heparin on the lipoprotein lipase activity was studied after its administration into fasting and fat loaded patients with heart ischemic disease, exhibiting various lipoprotein spectrum of blood. Heparin activated more distinctly the lipolytic enzymes in the patients kept on fatty diet as compared with the fasting patients. The difference was maximal in the patients with the IIa type of hypolipoproteinemia and minimal--in the patients with the IV type of the disease. The hypotriglyceridemic effect of heparin was found in all the groups examined; however, the least decrease in the triglyceride content occurred in the IV type of hypolipoproteinemia. These data demonstrate the relative deficiency of lipoprotein lipolysis in the type of hypolipoproteinemia studied.

[Lipoprotein lipase activity of ischemic heart disease patients with different types of hyperlipoproteinemia on the basis of fat loading]. / Aktivnost' lipoproteidlipazy u bol'nykh ishemicheskoi bolezn'iu serdtsa s razlichnymi tipami giperlipoproteidemii na fone zhirovoi nagruzki.

Lipolytic activity was distinctly increased in blood plasma of patients with ischemic heart impairment and various types of hyperlipoproteinemia after a test breakfast. The increase in lipolysis was due to elevation in the lipoprotein lipase activity in response to loading with lipids. Attempts to distinguish among the ischemic patients some subgroups on the basis only of the initial level of triglycerides in their blood plasma did not exhibit any differences in the enzymatic activity after the loading with lipids. This relationship was clearly noted in classification of the patients on the basis of the types of hyperlipoproteinemia. The earliest and the most pronounced increase in lipolytic activity in response to the loading with lipids was observed in the 11a type of hyperlipoproteinemia.

[Blood plasma lipolytic enzymes in experimental hyperlipidemia and atherosclerosis in rabbits]. / Lioliticheskie fermenty plazmy krovi pri éksperimental'noi giperlipidemii i ateroskleroze u krolikov.

The activity of blood plasma lipolytic enzymes was studied during the development of experimental hypercholesterolemia and atherosclerosis in rabbits. It is shown that lipoproteinlipase activity in post-heparin blood plasma increases most markedly 6 months after feeding rabbits with cholesterol. The concentration of cholesterol and triglycerides in blood plasma also reaches maximum values in this period. The activity of hepatic triglyceridelipase increases significantly within the same period. In rabbits with experimental atherosclerosis, just as in intact animals, however, the lipolytic activity of post-heparin blood plasma is almost entirely due to lipoproteinlipase.

[Activity of postheparin lipoprotein lipase in rabbit blood plasma]. / Aktivnost' postgeparinovoi lipoproteidlipazy plazmy krovi krolikov.

Activity of lipoprotein lipase was studied in rabbit blood plasma after administration of heparin at a dose 50 un/kg into animals. NaCl was added to incubation mixture at final concentration 1 M to differentiate the enzyme from liver triglyceride lipase. The salt inhibited strongly (sometimes completely) the lipolytic activity in rabbit postheparin blood plasma. These data suggest predominance of lipoprotein lipase, sensitive to NaCl, in total lipolytic activity of rabbit postheparin blood plasma. Only slight alterations in the value of total lipolytic activity and in activity, depending on lipoprotein lipase, were observed in rabbits maintained at high cholesterol diet. Under these conditions distinct increase in activity of triglyceride lipase, stable to NaCl , was not found.

[Neural regulation of the activity of energy metabolism enzymes in differently functioning rabbit skeletal muscles]. / O nervnoi reguliatsii aktivnosti fermentov énergeticheskogo obmena razlichno funktsioniruiushchikh skeletnykh myshts krolika.

Activities of phosphorylase, hexokinase and pyruvate kinase were studied in soluble fraction of cells from dissimilarly acting sceletal muscles of intact rabbits and from those tissues with impaired neural impulsation (denervation, experimental allergic neuritis). Activity of phosphorylase was found to be 2.2-fold higher and of hexokinase--4-fold lower in soluble fraction of quick muscle as compared with that of slow muscle. Due to denervation these differences were smoothed off. The same alterations in hexokinase activity were observed in muscles of rabbits with experimental allergic neuritis both after impairment of sensitive innervation and after denervation.

[Effect of a centrogenic fever on phosphorylase and pyruvate kinase activity in rabbit tissues]. / Vliianie "tsentrogennoi" likhoradki na aktivnost' fosforilazy i piruvatkinazy v tkaniakh krolikov.

Administration of pyrogenal into rabbits caused a decrease in the activity of phosphorylase A and pyruvate kinase in musculus gastrocnemius as well as pyruvate kinase -- in musculus soleus. The phosphorylase A activity was increased within 3 hrs after the drug administration but it was decreased after the treatment for three days. Administration of hydrocortisone decreased the activity of phosphorylase and pyruvate kinase in both muscles. Activities of total phosphorylase and phosphorylase A were decreased simultaneously with restoration of the pyruvate kinase activity in the both muscles after the complex administration of pyrogenal and hydrocortisone within 3 days. In liver tissue and kidney cortex activities of the enzymes did not differ from those of control animals under all the conditions studied. The various extent and direction in alterations of the same enzymes in dissimilar tissues of a single amnial after administration of pyrogenal and hydrocortisone were considered as the various adaptation of cells of different tissues to the effect of hydrocortisone and as the alteration in tissue reactivity in experimental fever animals to the hormonal effect.