The Influence of Trehalose on Atherosclerosis and Hepatic Steatosis in Apolipoprotein E Knockout Mice.

Atherosclerosis and nonalcoholic fatty liver disease (NAFLD) are frequent causes of death in the Western countries. Recently, it has been shown that autophagy dysfunction plays an important role in the pathogenesis of both atherosclerosis and NAFLD; thus, activators of autophagy might be useful for novel therapeutic interventions. Trehalose-a naturally occuring disaccharide present in plants, bacteria, fungi, insects, and certain types of shrimps-is a known inducer of autophagy. However, according to the literature, its anti-atherosclerotic and anti-steatotic potential seem to depend on the experimental setting. The aim of our study was to comprehensively describe the influence of a prolonged treatment with orally administered trehalose on the development of atherosclerotic lesions and hepatic steatosis in apolipoprotein E knockout (apoE-/-) mice in an experimental set up reflecting both moderate and severe proatherogenic conditions: male apoE-/- mice on a chow diet (CD) and female apoE-/- mice fed with a high-fat diet (HFD). We found that exogenous trehalose inhibited atherosclerosis and attenuated hepatic steatosis in apoE-/- mice. Such effects of trehalose were not associated with changes of plasma cholesterol, low-density lipoproteins (LDL), or high-density lipoproteins (HDL). Moreover, the anti-steatotic action of trehalose in the liver was associated with the induction of autophagy. The exact molecular mechanisms of both the anti-atherosclerotic action of trehalose and its inhibitory effect on liver steatosis require further clarification.

Quantitative proteomics reveals decreased expression of major urinary proteins in the liver of apoE/eNOS-DKO mice.

Endothelial nitric oxide synthase (eNOS)-derived nitric oxide (NO) plays an important role, not only in endothelium-dependent vasodilation but also in lipid and glucose homeostasis in the liver and exerts beneficial effects on mitochondrial biogenesis and respiration. Thus, the aim of our study was to use iTRAQ-based quantitative proteomics to investigate the changes in protein expression in the mitochondrial and cytosolic fractions isolated from the liver of the double (apolipoprotein E (apoE) and eNOS) knockout (apoE/eNOS-DKO) mice as compared to apoE KO mice (apoE-/- ) - an animal model of atherosclerosis and hepatic steatosis. Collectively, the deficiency of eNOS resulted in increased expression of proteins related to gluconeogenesis, fatty acids and cholesterol biosynthesis as well as the decreased expression of proteins participated in triglyceride breakdown, cholesterol transport, protein transcription & translation and processing in endoplasmic reticulum (ER). Moreover, one of the most downregulated proteins were major urinary proteins (MUPs), which are abundantly expressed in the liver and were shown to be involved in the regulation of lipid and glucose metabolism. The exact functional consequences of the revealed alterations require further investigation.

Optimization of quantitative proteomic analysis of clots generated from plasma of patients with venous thromboembolism.

BACKGROUND: It is well known that fibrin network binds a large variety of proteins, including inhibitors and activators of fibrinolysis, which may affect clot properties, such as stability and susceptibility to fibrinolysis. Specific plasma clot composition differs between individuals and may change in disease states. However, the plasma clot proteome has not yet been in-depth analyzed, mainly due to technical difficulty related to the presence of a highly abundant protein-fibrinogen and fibrin that forms a plasma clot. METHODS: The aim of our study was to optimize quantitative proteomic analysis of fibrin clots prepared ex vivo from citrated plasma of the peripheral blood drawn from patients with prior venous thromboembolism (VTE). We used a multiple enzyme digestion filter aided sample preparation, a multienzyme digestion (MED) FASP method combined with LC-MS/MS analysis performed on a Proxeon Easy-nLC System coupled to the Q Exactive HF mass spectrometer. We also evaluated the impact of peptide fractionation with pipet-tip strong anion exchange (SAX) method on the obtained results. RESULTS: Our proteomic approach revealed 476 proteins repeatedly identified in the plasma fibrin clots from patients with VTE including extracellular vesicle-derived proteins, lipoproteins, fibrinolysis inhibitors, and proteins involved in immune responses. The MED FASP method using three different enzymes: LysC, trypsin and chymotrypsin increased the number of identified peptides and proteins and their sequence coverage as compared to a single step digestion. Peptide fractionation with a pipet-tip strong anion exchange (SAX) protocol increased the depth of proteomic analyses, but also extended the time needed for sample analysis with LC-MS/MS. CONCLUSIONS: The MED FASP method combined with a label-free quantification is an excellent proteomic approach for the analysis of fibrin clots prepared ex vivo from citrated plasma of patients with prior VTE.

Proteomic Analysis of Mitochondria-Enriched Fraction Isolated from the Frontal Cortex and Hippocampus of Apolipoprotein E Knockout Mice Treated with Alda-1, an Activator of Mitochondrial Aldehyde Dehydrogenase (ALDH2).

The role of different genotypes of apolipoprotein E (apoE) in the etiology of Alzheimer's disease is widely recognized. It has been shown that altered functioning of apoE may promote 4-hydroxynonenal modification of mitochondrial proteins, which may result in mitochondrial dysfunction, aggravation of oxidative stress, and neurodegeneration. Mitochondrial aldehyde dehydrogenase (ALDH2) is an enzyme considered to perform protective function in mitochondria by the detoxification of the end products of lipid peroxidation, such as 4-hydroxynonenal and other reactive aldehydes. The goal of our study was to apply a differential proteomics approach in concert with molecular and morphological techniques to elucidate the changes in the frontal cortex and hippocampus of apolipoprotein E knockout (apoE-/-) mice upon treatment with Alda-1-a small molecular weight activator of ALDH2. Despite the lack of significant morphological changes in the brain of apoE-/- mice as compared to age-matched wild type animals, the proteomic and molecular approach revealed many changes in the expression of genes and proteins, indicating the impairment of energy metabolism, neuroplasticity, and neurogenesis in brains of apoE-/- mice. Importantly, prolonged treatment of apoE-/- mice with Alda-1 led to the beneficial changes in the expression of genes and proteins related to neuroplasticity and mitochondrial function. The pattern of alterations implies mitoprotective action of Alda-1, however, the accurate functional consequences of the revealed changes require further research.

Anti-Atherosclerotic Action of Agmatine in ApoE-Knockout Mice.

Atherosclerosis is an inflammatory disease in which dysfunction of mitochondria play an important role, and disorders of lipid management intensify this process. Agmatine, an endogenous polyamine formed by decarboxylation of arginine, exerts a protective effect on mitochondria and modulates fatty acid metabolism. We investigated the effect of exogenous agmatine on the development of atherosclerosis and changes in lipid profile in apolipoprotein E knockout (apoE-/-) mice. Agmatine caused an approximate 40% decrease of atherosclerotic lesions, as estimated by en face and cross-section methods with an influence on macrophage but not on smooth muscle content in the plaques. Agmatine treatment did not changed gelatinase activity within the plaque area. What is more, the action of agmatine was associated with an increase in the number of high density lipoproteins (HDL) in blood. Real-Time PCR analysis showed that agmatine modulates liver mRNA levels of many factors involved in oxidation of fatty acid and cholesterol biosynthesis. Two-dimensional electrophoresis coupled with mass spectrometry identified 27 differentially expressed mitochondrial proteins upon agmatine treatment in the liver of apoE-/- mice, mostly proteins related to metabolism and apoptosis. In conclusion, prolonged administration of agmatine inhibits atherosclerosis in apoE-/- mice; however, the exact mechanisms linking observed changes and elevations of HDL plasma require further investigation.

The impact of mitochondrial aldehyde dehydrogenase (ALDH2) activation by Alda-1 on the behavioral and biochemical disturbances in animal model of depression.

The etiology of depression remains still unclear. Recently, it has been proposed, that mitochondrial dysfunction may be associated with development of mood disorders, such as depression, bipolar disorder and anxiety disorders. Mitochondrial aldehyde dehydrogenase (ALDH2), an enzyme responsible for the detoxification of reactive aldehydes, is considered to exert protective function in mitochondria. We investigated the influence of Alda-1, a small-molecule activator of ALDH2, on depressive- and anxiety-like behaviors in an animal model of depression - the prenatally stressed rats - using behavioral, molecular and proteomic methods. Prolonged Alda-1 administration significantly increased the climbing time, tended to reduce the immobility time and increased the swimming time of the prenatally stressed rats in the forced swim test. Moreover, treatment of prenatally stressed rats with Alda-1 significantly increased number of entries into the open arms of the maze and the time spent therein, as assessed by elevated plus-maze test. Such actions were associated with reduction of plasma 4-HNE-protein content, decrease of TNF-α mRNA and increase of PGC-1α (regulator of mitochondrial biogenesis) mRNA level in the frontal cortex and hippocampus of the prenatally stressed rats as well as with normalization of peripheral immune parameters and significant changes in expression of 6 and 4 proteins related to mitochondrial functions in the frontal cortex and hippocampus, respectively. Collectively, ALDH2 activation by Alda-1 led to a significant attenuation of depressive- and anxiety-like behaviors in the prenatally stressed rats. The pattern of changes suggested mitoprotective effect of Alda-1, however the exact functional consequences of the revealed alterations require further investigation.

The influence of angiotensin-(1-7) Mas receptor agonist (AVE 0991) on mitochondrial proteome in kidneys of apoE knockout mice.

Excessive action of angiotensin II on mitochondria has been shown to play an important role in mitochondrial dysfunction, a common feature of atherogenesis and kidney injury. Angiotensin-(1-7)/Mas receptor axis constitutes a countermeasure to the detrimental effects of angiotensin II on AT1 receptors. The aim of the study was to assess the effects of angiotensin-(1-7) peptidomimetic AVE0991 on the kidney mitochondrial proteome in widely used animal model of atherosclerosis (apoE(-/-) mice). Proteins changed in apoE(-/-) mice belonged to the groups of antioxidant enzymes, apoptosis regulators, inflammatory factors and metabolic enzymes. Importantly, AVE0991 partially reversed atherosclerosis-related changes in apoE(-/-) mice.

Inactivation of heparin by cationically modified chitosan.

This study was performed to evaluate the ability of N-(2-hydroxypropyl)-3-tri methylammonium chitosan chloride (HTCC), the cationically modified chitosan, to form biologically inactive complexes with unfractionated heparin and thereby blocking its anticoagulant activity. Experiments were carried out in rats in vivo and in vitro using the activated partial thromboplastin time (APTT) and prothrombin time (PT) tests for evaluation of heparin anticoagulant activity. For the first time we have found that HTCC effectively neutralizes anticoagulant action of heparin in rat blood in vitro as well as in rats in vivo. The effect of HTCC on suppression of heparin activity is dose-dependent and its efficacy can be comparable to that of protamine-the only agent used in clinic for heparin neutralization. HTCC administered i.v. alone had no direct effect on any of the coagulation tests used. The potential adverse effects of HTCC were further explored using rat experimental model of acute toxicity. When administered i.p. at high doses (250 and 500 mg/kg body weight), HTCC induced some significant dose-dependent structural abnormalities in the liver. However, when HTCC was administered at low doses, comparable to those used for neutralization of anticoagulant effect of heparin, no histopathological abnormalities in liver were observed.

Role of angiotensin-(1-7) in gastroprotection against stress-induced ulcerogenesis. The involvement of mas receptor, nitric oxide, prostaglandins, and sensory neuropeptides.

Angiotensin-(1-7) [Ang-(1-7)] is a major vasoactive metabolite of angiotensin I (Ang I), both being important components of the renin-angiotensin system (RAS). Ang-(1-7) acting via Mas receptor was documented in kidneys, heart, brain, and gastrointestinal (GI)-tract. We studied the gastroprotective activity of exogenous Ang-(1-7) in rats exposed to water immersion and restraint stress (WRS) without or with A-779 [d-Ala7-Ang-(1-7), an antagonist of Ang-(1-7) Mas receptors], AVE 0991 (5-formyl-4-methoxy-2-phenyl-1[[4-[2-(ethylaminocarbonylsulfonamido)-5-isobutyl-3-thienyl]-phenyl]-methyl]-imidazole), the agonist of Ang-(1-7) receptor, as well as the inhibition of nitric-oxide (NO) synthase, the suppression of cyclo-oxygenase (COX)-1 (indomethacin, SC-560 [5-(4-chloro-phenyl)-1-(4-methoxyphenyl)-3-trifluoromethyl-pyrazole]), the activity COX-2 (rofecoxib), and denervation with capsaicin. The mRNA expression of constitutively expressed nitric-oxide synthase (cNOS), inducible nitric-oxide synthase (iNOS), interleukin (IL)-1ß, and tumor necrosis factor (TNF)-α was analyzed by reverse transcription polymerase chain reaction. The WRS lesions were dose-dependently reduced by pretreatment with Ang-(1-7), which also caused an increase in gastric blood flow (GBF) and luminal content of NO. COX-1 and COX-2 inhibitors or L-NNA (N5-[imino(nitroamino)methyl]-L-ornithine) reversed the reduction in lesion number and the rise in GBF evoked by Ang-(1-7). Ang II augmented the WRS lesions, decreased GBF and increased the plasma IL-1ß and TNF-α levels. Capsaicin denervation attenuated the reduction of Ang-(1-7)-induced gastric lesions and the rise in GBF; these effects were restored by supplementation with calcitonin gene-related peptide (CGRP). The cNOS mRNA was upregulated while iNOS, IL-1ß and TNF-α mRNAs were downregulated in Ang-(1-7)-pretreated rats. We conclude that Ang-(1-7), in contrast to Ang II, which worsened WRS ulcerogenesis, affords potent gastroprotection against WRS ulcerogenesis via an increase in GBF mediated by NO, endogenous prostaglandins, sensory neuropeptides, and anti-inflammatory action involving the inhibition of proinflammatory markers iNOS, IL-1ß, and TNF-α.

Assessment of angiotensin I metabolism in the human placenta using an LC/MS method.

The local renin-angiotensin system (RAS) in the placenta plays a very important role in placental development. It is well known that during normal pregnancy most of the circulating and local RAS components are over-expressed and any disruption of this new balance may cause pregnancy complications. The aim of this study was to assess the metabolism of Ang I in placentas from normal pregnancy, in an ex vivo model, using an LC/MS method. The obtained results suggest that placental tissue is able to produce many angiotensin peptides but the main metabolite is Ang-(1-7).

Beneficial effect of amantadine on postoperative pain reduction and consumption of morphine in patients subjected to elective spine surgery.

OBJECTIVE: To analyze the effect of coadministration of morphine and amantadine on postoperative pain reduction and morphine consumption in patients after elective spine surgery. METHODS: In double-blinded study, 60 patients (ASA physical status I-II) were randomized into two groups. Group A was given oral amantadine 50 or 100 mg 1 hour before surgery and 8, 20, 32 hours after operation. Group P received placebo at identical times. Pain was assessed using numerical rating scale before first administration of morphine and in 2, 3, 4, 6, 24, and 48 hours after operation. The amounts of morphine consumed were recorded up to 48 hours after surgery. Blood samples were taken twice in 2 hours after surgery and plasma levels of morphine and its main metabolites were measured. RESULTS: As compared with placebo, amantadine significantly reduced intra-operative Fentanyl use and sensation of postoperative pain. Up to 48 hours after operation, the cumulative consumption of morphine was 25% lower in the amantadine group. Moreover, intensity of nausea and vomiting tended to be lower in A group. Starting from 12th hour after surgery, the level of postoperative sedation was lower in patients who received amantadine, as compared with placebo group. No significant differences in plasma levels of morphine ant its metabolites were observed between A and P groups. CONCLUSIONS: Pre- and postoperative administration of amantadine significantly reduced fentanyl use during operation, as well as reduced the postoperative pain and decreased morphine consumption in young patients undergoing orthopedic surgery.

The effect of AVE 0991, nebivolol and doxycycline on inflammatory mediators in an apoE-knockout mouse model of atherosclerosis.

BACKGROUND: The aim of this study was to investigate whether the 3 different substances that can decrease the development of atherosclerosis--nebivolol, AVE 0991 and doxycycline--could at the same time diminish the level of inflammatory indicators interleukin-6 (IL-6), interleukin-12 (IL-12), serum amyloid A (SAA), and monocyte chemotactic protein-1 (MCP-1). MATERIAL/METHODS: Forty 8-week-old female apoE-knockout mice on the C57BL/6J background were divided into 4 groups and put on chow diet for 4 months. Three experimental groups received the same diet as a control group, mixed with AVE 0991 at a dose 0.58 µmol per kg of body weight per day, nebivolol at a dose 2.0 µmol per kg of body weight per day, and doxycycline at a dose 1.5 mg per kg of body weight per day. At the age of 6 months, the mice were sacrificed. RESULTS: All inflammatory indicators (MCP-1, IL-6, IL-12 and SAA) were diminished by AVE 0991. There was also a tendency to lower MCP-1, IL-6, IL-12 and SAA levels by nebivolol and doxycycline; however, it did not reach statistical significance. CONCLUSIONS: Of the 3 presented substances, only AVE 0991 was able to diminish the rise of inflammatory markers. Therefore, drug manipulations in the renin-angiotensin-aldosterone axis seem to be the most promising in the future treatment of atherogenesis.

[Endothelial dysfunction related to oxidative stress and inflammation in perivascular adipose tissue]. / Zaburzenia funkcji sródblonka naczyn wywolane stresem oksydacyjnym i stanem zapalnym w okolonaczyniowej tkance tluszczowej.

Endothelial dysfunction plays an important role in the pathogenesis of many common diseases, like atherosclerosis and hypertension. The key role of the interaction between oxidative stress and inflammation in causal mechanisms of these diseases is widely accepted. Until recently, perivascular adipose tissue was not taken into account while looking at mechanisms of these disorders. However, it has recently been demonstrated that most processes involved in endothelial dysfunction development are taking place in this tissue. Adipocytes are an important source of free radicals and pro-inflammatory cytokines. These molecules lead to further enhancement of oxidative stress, through uncoupling of endothelial nitric oxide synthase (eNOS) and production of peroxynitrite radical instead of nitric oxide which further disrupts eNOS function. In addition, macrophages and T lymphocytes infiltrate adipose tissue as a result of chemotactic proteins release, upon oxidative stress activation, which further enhances inflammation. Thus, the chronic inflammation, which develops in this compartment of adipose tissue in patients with obesity, is the first step in the development of atherosclerotic plaque or hypertension. That is why comprehensive understanding of ongoing processes within perivascular adipocytes is so important.

[Metformin--an inhibitor of early stages of protein glycation]. / Metformina--inhibitor wczesnych etapów glikacji bialek.

Nonenzymatic glycation of proteins is associated with the long-term diabetes complication. The aim of this work was to examine in vitro the infuence of metformin on glycated proteins formation by mass spectrometry (ESI/MS, LC/MS/MS) and spectrofluorimetric method. Obtained results suggest that metformin dose-dependently inhibits early stage of Maillard reaction, although with the weaker potency than known glycation inhibitor aminoguanidine.

Anti-atherosclerotic action of GW9508 - Free fatty acid receptors activator - In apoE-knockout mice.

BACKGROUND: In the past two decades, enhanced understanding of the biology of G-protein-coupled receptors (GPRs) has led to the identification of several such receptors as novel targets for free fatty acids (FFAs). Two GPRs, FFAR1 and FFAR4, have received special attention in the context of chronic inflammatory diseases, thanks to their anti-inflammatory activities. METHODS: The present study investigates the influence of prolonged treatment with GW9508 - agonist of FFAR1 and FFAR4 - on the development of atherosclerosis plaque in apoE-knockout mice, using morphometric and molecular methods. RESULTS: GW9508 administration has led to the reduction of atheroscletoric plaque size in an apoE-knockout mice model. Moreover, a FFAR1/FFAR4 agonist reduced the content of macrophages by almost 20%, attributed by immunohistochemical phenotyping to the pro-inflammatory M1-like activation state macrophages. CONCLUSIONS: Prolonged administration of GW9508 resulted in significant amelioration of atherogenesis, providing evidence that the strategy based on macrophage phenotype switching toward an M2-like activation state via stimulation of FFAR1/FFAR4 receptors holds promise for a new approach to the prevention or treatment of atherosclerosis.

[Evaluation of morphine metabolism in presence of amantadine and dextromethorphan in human serum by high performance liquid chromatography coupled with mass spectrometry (LC/MS) method]. / Metabolizm morfiny w obecnosci amantadyny i dekstrometorfanu u ludzi--ocena metoda wysokosprawnej chromatografii cieczowej sprzezonej ze spektrometria mas (LC/MS).

In the present study we assessed by LC/MS method the influence of amantadine and dextromethorphan on morphine metabolism in humans in order to explain clinically observed phenomenon of amplification of analgesic action of morphine by these drugs. Neither dextromethorphan nor amantadine influenced the rate of morphine degradation and concentration of morphine metabolites. Thus, our results suggest pharmacodynamical, not pharmacokinetic mechanism of interaction.

In vitro maturation of monocyte-derived dendritic cells results in two populations of cells with different surface marker expression, independently of applied concentration of interleukin-4.

Dendritic cells (DCs) play a crucial role in the development of adaptive immune response. Monocyte-derived dendritic cells (MDDCs) are generated in vitro to study DC biology and for use in immunotherapy. However, procedures to generate MDDCs vary and an impact this may have on their final phenotype is insufficiently studied. Monocytes isolated from healthy blood donors were cultured for 7 days with granulocyte-macrophage colony stimulating factor (50 ng/mL) and low (500 IU/mL, L-IL4) or high (1000 IU/mL, H-IL4) interleukin 4 (IL4), to obtain immature DCs and for the following 2 days with addition of soluble CD40 ligand (500 ng/mL) and prostaglandin E2 (1 µg/mL) to obtain mature DCs. We measured mean fluorescence activity and percentage of cells, positive for CD14, HLA-DR, CD80, CD83, CD86, CCR7, and CD1a or CD209 markers after 7 and 9 days of culture, in both IL4 concentrations. Percentage of positively staining mature MDDCs was higher than among immature cells, for all studied markers. Interestingly, varying IL4 concentrations had negligible impact on staining of mature MDDCs. However, immature L-IL4 cultured MDDCs were less intensely stained for HLA-DR and CD209 than H-IL4 immature DCs. Flow cytometry revealed presence of 2 populations of cells (dominant P1 and less prevalent P2), when either L-IL4 or H-IL4 was used. Among mature MDDCs, population P1 had higher percentage of positively staining cells than P2, for all studied markers except CCR7. In conclusion, both concentrations of IL4 produce in vitro heterogeneous populations of mature MDDCs with similar staining for cell surface markers.

Differences in plasma fibrin clot composition in patients with thrombotic antiphospholipid syndrome compared with venous thromboembolism.

The prothrombotic fibrin clot phenotype has been reported in patients with thrombotic antiphospholipid syndrome (APS) and venous thromboembolism (VTE). Protein composition of plasma fibrin clots in APS has not been studied. We evaluated 23 patients with thrombotic APS, 19 with VTE alone, and 20 well-matched controls. A proteomic analysis of fibrin clots generated from citrated plasma was based on liquid chromatography-mass spectrometry. Plasma levels of thrombospondin-1 (TSP1), apolipoprotein(a), A-I, and B-100, complement components (C)3a, C5b-C9, histidine-rich glycoprotein (HRG), and prothrombin were evaluated using immunoenzymatic tests. In plasma fibrin clots of APS patients, compared with VTE subjects and controls, we identified decreased amounts of (pro)thrombin, antithrombin-III, apolipoprotein A-I, and HRG with no differences in plasma levels of antithrombin, prothrombin, along with lower plasma HRG and apolipoprotein A-I. In APS patients, plasma HRG positively correlated with amounts of clot-bound HRG, while apolipoprotein A-I was inversely associated with clot-bound levels of this protein. The most predominant proteins within the clots of APS patients were bone marrow proteoglycan, C5-C9, immunoglobulins, apolipoprotein B-100, platelet-derived proteins, and TSP1. Our study is the first to demonstrate differences in the protein composition of fibrin clots generated from plasma of thrombotic APS patients versus those with VTE alone.

Vasodilatory Efficacy and Impact of Papaverine on Endothelium in Radial Artery Predilatation for CABG Surgery: in Search for Optimal Concentration.

OBJECTIVE: The aim of this study was to compare the efficacy of two different papaverine concentrations (0.5 mg/ml and 2 mg/ml) for vasospasm prevention and their impact on endothelium integrity. METHODS: We have studied distal segments of radial arteries obtained by no-touch technique from coronary artery bypass graft (CABG) patients (n=10). The vasodilatory effect of papaverine (concentrations of 0.5 mg/ml and 2 mg/ml) was assessed in vitro, in isometric tension studies using ex vivo myography (organ bath technique) and arterial rings precontracted with potassium chloride (KCl) and phenylephrine. The impact of papaverine on endothelial integrity was studied by measurement of the percentage of vessel's circumference revealing CD34 endothelial marker. RESULTS: 2 mg/ml papaverine concentration showed stronger vasodilatatory effect than 0.5 mg/ml, but it caused significantly higher endothelial damage. Response to KCl was 7.35±3.33 mN for vessels protected with papaverine 0.5 mg/ml and 2.66±1.96 mN when papaverine in concentration of 2 mg/ml was used. The histological examination revealed a significant difference in the presence of undamaged endothelium between vessels incubated in papaverine 0.5 mg/ml (72.86±9.3%) and 2 mg/ml (50.23±13.42%), P=0.002. CONCLUSION: Papaverine 2 mg/ml caused the higher endothelial damage. Concentration of 0.5 mg/ml caused better preservation of the endothelial lining.

Ticlopidine attenuates progression of atherosclerosis in apolipoprotein E and low density lipoprotein receptor double knockout mice.

Platelets are involved in the development of atherothrombosis. However, the anti-atherosclerotic effects of thienopiridines have not been, as yet, proven. We analyzed the effects of ticlopidine on atherogenesis in apolipoprotein E/low density lipoprotein receptor double knockout (apoE/LDLR(-/-)) mice. 2-month-old apoE/LDLR(-/-) mice fed a Western diet (21% fat, 0.15% cholesterol) were treated with ticlopidine (90 mg/kg/day) for a period of 4 months. In 6-month-old apoE/LDLR(-/-) mice treated with ticlopidine and in their non-treated counterparts we analyzed: cholesterol and triglyceride levels, the size of atherosclerotic plaques in aortic roots (oil red-O staining, cross-section method), and in the whole aorta (Sudan IV staining, en face method), the number of macrophages in atherosclerotic plaque (CD68 staining), as well as the endothelial function in the isolated thoracic aorta. Concentrations of total cholesterol and triglycerides in plasma were not altered by treatment with ticlopidine. However, the size of atherosclerotic plaques measured in aortic roots by the cross-section method and the number of macrophages estimated by anti-CD68 staining were significantly reduced by ticlopidine treatment. In contrast, the effect of ticlopidine on the area covered by plaques in the whole aorta (en face analysis) was not statistically significant. Importantly, acetylcholine-induced vasodilation in isolated aorta was improved in ticlopidine-treated apoE/LDLR(-/-) mice as compared to their non-treated counterparts. In conclusion, ticlopidine attenuates the progression of atherosclerosis and improves the endothelial function in apoE/LDLR(-/-) mice.