OBJECTIVE: To study the effect of gradient shear stress on platelet aggregation by microfluidic chip Technology. METHODS: Microfluidic chip was used to simulate 80% fixed stenotic microchannel, and the hydrodynamic behavior of the stenotic microchannel model was analyzed by the finite element analysis module of sollidwork software. Microfluidic chip was used to analyze the adhesion and aggregation behavior of platelets in patients with different diseases, and flow cytometry was used to detect expression of the platelet activation marker CD62p. Aspirin, Tirofiban and protocatechuic acid were used to treat the blood, and the adhesion and aggregation of platelets were observed by fluorescence microscope. RESULTS: The gradient fluid shear rate produced by the stenosis model of microfluidic chip could induce platelet aggregation, and the degree of platelet adhesion and aggregation increased with the increase of shear rate within a certain range of shear rate. The effect of platelet aggregation in patients with arterial thrombotic diseases were significantly higher than normal group (P<0.05), and the effect of platelet aggregation in patients with myelodysplastic disease was lower than normal group (P<0.05). CONCLUSION The microfluidic chip analysis technology can accurately analyze and evaluate the platelet adhesion and aggregation effects of various thrombotic diseases unde the environment of the shear rate, and is helpful for auxiliary diagnosis of clinical thrombotic diseases.
Humans ; Microfluidics ; Platelet Adhesiveness ; Platelet Aggregation ; Blood Platelets/metabolism* ; Platelet Aggregation Inhibitors/pharmacology* ; Platelet Activation/physiology* ; Thrombosis

BACKGROUND: Resveratrol has been shown to inhibit platelet aggregation. However, the mechanism for this action of resveratrol remains to be clarified. The purpose of this study was to elucidate the Ca METHODS: Ca RESULTS: Thapsigargin-induced Ca CONCLUSIONS The results suggest that resveratrol inhibits thrombin-induced platelet aggregation through decreasing Ca
Antioxidants/administration & dosage* ; Calcium/physiology* ; Humans ; Platelet Aggregation/drug effects* ; Platelet Aggregation Inhibitors/pharmacology* ; Resveratrol/pharmacology* ; Signal Transduction/drug effects*

BACKGROUNDCoronary microembolization (CME) has been frequently seen in acute coronary syndromes and percutaneous coronary intervention. Small animal models are required for further studies of CME related to severe prognosis. This study aimed to explore a new mouse model of CME.

METHODSThe mouse model of CME was established by injecting polystyrene microspheres into the left ventricular chamber during 15-s occlusion of the ascending aorta. Based on the average diameter and dosage used, 30 C57BL/6 male mice were randomly divided into five groups (n = 6 in each): 9 μm/500,000, 9 μm/800,000, 17 μm/200,000, 17 μm/500,000, and sham groups. The postoperative survival and performance of the mice were recorded. The mice were sacrificed 3 or 10 days after the surgery. The heart tissues were harvested for hematoxylin and eosin staining and Masson trichrome staining to compare the extent of inflammatory cellular infiltration and fibrin deposition among groups and for scanning transmission electron microscopic examinations to see the ultrastructural changes after CME.

RESULTSSurvival analysis demonstrated that the cumulative survival rate of the 17 μm/500,000 group was significantly lower than that of the sham group (0/6 vs. 6/6, P = 0.001). The cumulative survival rate of the 17 μm/200,000 group was lower than those of the sham and 9 μm groups with no statistical difference (cumulative survival rate of the 17 μm/200,000, 9 μm/800,000, 9 μm/500,000, and sham groups was 4/6, 5/6, 6/6, and 6/6, respectively). The pathological alterations were similar between the 9 μm/500,000 and 9 μm/800,000 groups. The extent of inflammatory cellular infiltration and fibrin deposition was more severe in the 17 μm/200,000 group than in the 9 μm/500,000 and 9 μm/800,000 groups 3 and 10 days after the surgery. Scanning transmission electron microscopic examinations revealed platelet aggregation and adhesion, microthrombi formation, and changes in cardiomyocytes.

CONCLUSIONThe injection of 500,000 polystyrene microspheres at an average diameter of 9 μm is proved to be appropriate for the mouse model of CME based on the general conditions, postoperative survival rates, and pathological changes.

Animals ; Brain ; pathology ; Coronary Occlusion ; pathology ; surgery ; Coronary Vessels ; pathology ; surgery ; ultrastructure ; Disease Models, Animal ; Embolization, Therapeutic ; Kidney ; pathology ; Male ; Mice ; Mice, Inbred C57BL ; Microscopy, Electron, Scanning Transmission ; Myocardium ; pathology ; Platelet Aggregation ; physiology

Although the effects of the rice bran have recently been investigated, there is no information regarding platelet physiology available. However, it is well known that fermented natural plants have a beneficial effect on cardiovascular diseases. Therefore, this study was conducted to investigate whether fermented rice bran extract (FRBE) with several plants (Artemisia princeps, Angelica Gigantis Radix, Cnidium officinale, and Camellia sinensis) affected agonist-induced platelet aggregation, and if so, what the underlying mechanism of its activity was. We performed several experiments, including in vitro platelet aggregation, intracellular calcium concentration and adenosine triphosphate release. In addition, the activation of integrin alphaIIbbeta3 was determined using fibrinogen binding. Thrombus formation was also evaluated in vivo using an arterio-venous shunt model. The FRBE inhibited collagen-induced platelet aggregation in a concentration-dependent manner. FRBE significantly and dose dependently attenuated thrombus formation using rat arterio-venous shunt. FRBE suppressed the intracellular calcium mobilization in collagen-stimulated platelets. We also found that FRBE inhibited extracellular stimuli-responsive kinase 1/2, p38-mitogen-activated protein kinases and c-Jun N-terminal kinase phosphorylation. These results suggested that FRBE inhibited collagen-induced platelet aggregation, which was mediated by modulation of downstream signaling molecules. In conclusion, FRBE could be developed as a functional food against aberrant platelet activation-related cardiovascular diseases.
Adenosine Triphosphate ; Angelica ; Animals ; Blood Platelets ; Calcium ; Camellia ; Cardiovascular Diseases ; Cnidium ; Collagen ; Fibrinogen ; Functional Food ; JNK Mitogen-Activated Protein Kinases ; Phosphorylation ; Phosphotransferases ; Physiology ; Platelet Aggregation ; Platelet Glycoprotein GPIIb-IIIa Complex ; Protein Kinases ; Rats ; Thrombosis

The changes of bioactive constituents were analyzed for Puhuang-Wulingzhi before and after compatibility and the antiplatelet and antithrombin activitives were evaluated in order to elucidate the scientific and reasonable of Puhuang-Wulingzhi compatibility. UPLC-QTOF-MA-Markerlynx, principal component analysis (PCA) and orthogonal partial least-squares discriminant analysis were used for data analysis and tracking changes of chemical composition during the decocting process. In vitro platelet aggregation induced by ADP, thrombin time(TT) and prothrombin time (PT) were investigated for Puhuang-Wulingzhi before and after compatibility. The results showed that significant differences were found between the mixed decoction and codecoction of Wulingzhi and Puhuang. Five compounds changed obviously were identified as typhaneoside, naringenin, isorhamnetin-3-O-ruinoside, quercetin-3-O-neohesperidoside, kaempferol-3-O-neohesperidoside. The codecoction, comparing with the single decoction, was more significant in antiplatelet aggregation and could prolong thrombin time. In the same crude drug dose, the thrombin time (TT) elongation were greater. These data could provide references for elucidation of bioactive components for this herb pair.
Animals ; Antithrombins ; chemistry ; pharmacology ; Blood Platelets ; drug effects ; physiology ; Drugs, Chinese Herbal ; chemistry ; pharmacology ; Female ; Humans ; Molecular Structure ; Platelet Aggregation ; drug effects ; Rabbits ; Thrombin Time

The chemical constituents of Safflower injection were isolated and purified by polyamide, silica gel, Sephadex LH-20, ODS column chromatographies and preparative HPLC. As a result, sixteen compounds have been isolated. Based on the spectral data analysis, their structures were elucidated as scutellarin (1), kaempferol-3-O-β-rutinoside(2), hydroxysafflor yellow A(3), rutin (4), coumalic acid(5), adenosine(6), syringoside(7), (3E)-4-(4'-hydroxyphenyl)-3-buten-2-one(8), (8Z)-decaene-4, 6-diyne-1-Oβ-D-glucopyranoside(9), 4-hydroxybenzaldehyde (10), (2E, 8E) -tetradecadiene-4, 6-diyne-1, 12, 14-triol-1-O-β-D-glucopyranoside (11), kaem-pferol-3-O-β-sophorose (12), uridine (13), roseoside (14), cinnamic acid (15), and kaempferol (16). Compounds 1,2,7,9,11 and 12 were isolated from the Safflower injection for the first time. The anti-platelet aggregation activities of the isolated compounds were assayed. The results indicated all tested compounds exhibited potent activity except for 5, while 2, 3, 9 and 12 showed strong activity against platelet aggregation.
Animals ; Blood Platelets ; drug effects ; physiology ; Carthamus tinctorius ; chemistry ; Drugs, Chinese Herbal ; chemistry ; isolation & purification ; pharmacology ; Fibrinolytic Agents ; chemistry ; isolation & purification ; pharmacology ; Molecular Structure ; Platelet Aggregation ; drug effects ; Rabbits ; Spectrometry, Mass, Electrospray Ionization

Microcirculatory dysfunction of local wounds and distant tissues after burns results in ischemia and hypoxia of tissues and organs, thus affecting the course and prognosis of burns. Platelet is an important component of blood, and the changes in its rheological behavior influence the blood flow in the microcirculation, as well as the microvascular structure and function. The abnormality of platelet rheological behavior plays an important role in the occurrence and development of microcirculatory dysfunction after burn. Changes in rheological behavior of platelets are due to changes in platelet morphology, adhesion, aggregation, shrinkage functions, and release reaction. Investigation of platelet rheological behavior and its regulation after burn may be of significant implication in the analysis of patient's condition and instruction for treatment. This article reviews the changes in platelet rheological behavior and its regulation after burn in the aspects of morphology, adhesion, aggregation, shrinkage functions, and release reaction.
Blood Platelets ; physiology ; Burns ; blood ; physiopathology ; Hemodynamics ; Humans ; Microcirculation ; Platelet Aggregation ; Rheology

Animals ; Cardiovascular Diseases ; etiology ; metabolism ; Humans ; Inflammation ; metabolism ; Periodontitis ; complications ; metabolism ; microbiology ; Platelet Aggregation ; physiology ; Porphyromonas gingivalis ; pathogenicity ; RNA, Messenger ; metabolism ; Receptor, PAR-1 ; metabolism ; Receptor, PAR-2 ; genetics ; metabolism ; Receptors, Proteinase-Activated ; metabolism ; Receptors, Thrombin ; metabolism

OBJECTIVETo investigate the influence of high-voltage electrical burn (HEB) on the aggregation and adhesion of platelet and leukocyte in rats and the interventional effect of pentoxifylline (PTX).

METHODSOne hundred and eighty SD rats were divided into control, electrical burn (EB), and pentoxifylline treatment (PT) groups according to the random number table, with 60 rats in each group. (1) Ten rats were taken from each group at 15 minutes before injury for the observation of the microcirculatory perfusion of chest skin with Laser Doppler Perfusion Imager (LDPI), and the number of leukocyte adherent to mesenteric venule with Bradford Variable Projection Microscope (BVPM). Serum was collected from heart blood to determine the contents of platelet activating factor (PAF), thromboxane B2 (TXB2), prostacyclin (PGI2), P-selectin, E-selectin and L-selectin by double-antibody sandwich enzyme-linked immunosorbent assay. The ratio of TXB2 to PGI2 was calculated therefrom. (2) Model of HEB was reproduced in the remaining 50 rats of EB group and that of PT group with voltage regulator and experimental transformer (the electrical current applied to the left forelimb and exited from the right hind limb). The remaining 50 rats of control group were sham injured with the same devices without electric current. Within 2 minutes post injury (PIM), rats in control group and EB group were intraperitoneally injected with 2 mL isotonic saline, while rats in PT group were intraperitoneally injected with 2 mL pentoxifylline (50 mg/mL). At PIM 5 and 1, 2, 4, 8 hour(s) post injury (PIH), 10 rats of every group were randomly chosen at each time point for the observation of the microcirculatory perfusion of chest skin and the number of leukocytes adherent to mesenteric venule through the same method as used above, and the levels of the related factors of aggregation and adhesion of platelets and leukocytes were determined, and then the relative ratio was calculated. Data were processed with the analysis of variance of factorial design and LSD test.

RESULTSThe contents of PAF, TXB2, PGI2, P-selectin, E-selectin, L-selectin, and the ratio of TXB2 to PGI2, as well as the number of adhered leukocyte in EB group were higher, while the microcirculatory perfusion value was lower than those of control group, with F values from 854.20 to 8156.52, P values all below 0.01. The microcirculatory perfusion value and PGI2 content of PT group were higher, while the contents or number of other indexes were lower than those of EB group, with F values from 33.18 to 1033.99, P values all below 0.01. Only the data within EB group and PT group were comparable. The contents of PAF, TXB2, PGI2, P-selectin, E-selectin, L-selectin, and the ratio of TXB2 to PGI2, as well as the number of adhered leukocyte in EB group and PT group at each time point were significantly higher than those at 15 minutes before injury, while the microcirculation perfusion value was significantly lower than that at 15 minutes before injury (P values all below 0.001), with the exception of the ratio of TXB2 to PGI2 in PT group and E-selectin in EB group and PT group at PIM 5. The contents of PAF, TXB2, and E-selectin and the ratio of TXB2 to PGI2 in EB group peaked at PIH 4, and they were respectively (9.3 ± 0.9) ng/mL, (14.31 ± 0.65) nmol/mL, (271.2 ± 18.4) ng/mL and 4.62 ± 0.26. The contents of PGI2 and P-selectin, and the number of adhered leukocyte in EB group peaked at PIH 8, and they were respectively (3.98 ± 0.24) nmol/mL, (514 ± 24) ng/mL, and (25.50 ± 4.14) per 100 µm venule. The content of L-selectin peaked at PIH 2 [(876 ± 54) ng/mL]. The microcirculatory perfusion value was lowest at PIM 5 [(1.17 ± 0.10) V].

CONCLUSIONSHEB can increase the contents of PAF, TXB2, PGI2, P-selectin, E-selectin, L-selectin, the ratio of TXB2 to PGI2, and the number of adhered leukocyte, as well as decrease the skin microcirculatory perfusion value. PTX can inhibit the aggregation and adhesion of platelets and leukocytes through increasing the content of PGI2 and decreasing contents of other factors mentioned above, thus alleviating the microcirculatory dysfunction after HEB.

Animals ; Blood Platelets ; drug effects ; Burns, Electric ; blood ; physiopathology ; Leukocytes ; drug effects ; physiology ; Male ; Pentoxifylline ; pharmacology ; Platelet Aggregation ; drug effects ; Rats ; Rats, Sprague-Dawley

The purpose of this study was to evaluate in vitro the effects of hydrocortisone and aminophylline on adenosine diphosphate (ADP)-induced platelet aggregation in horses. Blood samples from 30 healthy Thoroughbred horses were collected by via jugular venipuncture to assess platelet aggregation. Platelet-rich and platelet-poor plasma were prepared from all samples by centrifugation and divided into three different aliquots. In the first aliquot, platelet aggregation was measured after platelet activation with 1 microM and 0.5 microM ADP (Group A). In the other two aliquots, the effect of a 10 min preincubation with hydrocortisone (Group B) or aminophylline (Group C) on ADP-induced aggregation at final ADP concentrations of 1 microM and 0.5 microM was observed. Platelet aggregation, recorded by an aggregometer, was evaluated by measuring the maximum degree of platelet aggregation and the initial velocities of platelet aggregation were obtained. Our results demonstrated the inhibitory effect of hydrocortisone and the induction effect of aminophylline on equine platelet responses in vitro.
Adenosine Diphosphate/pharmacology ; Aminophylline/*pharmacology ; Animals ; Anti-Inflammatory Agents/*pharmacology ; Female ; Horses/*physiology ; Hydrocortisone/*pharmacology ; Male ; Platelet Aggregation/*drug effects