Inhibitory effects of antibiotics on platelet aggregation in vitro

1997 ◽  
Vol 16 (11) ◽  
pp. 662-666 ◽  
Author(s):  
Hiroko Kariyazono ◽  
Kazuo Nakamura ◽  
Terutoshi Shinkawa ◽  
Yukinori Moriyama ◽  
Hitoshi Toyohira ◽  
...  
Keyword(s):  
Platelet Aggregation ◽  
Blood Concentration ◽  
Chemical Structure ◽  
Inhibitory Action ◽  
Adenosine Diphosphate ◽  
Inhibitory Effect ◽  
Carboxyl Group ◽  
Inhibitory Effects ◽  
Induced Aggregation

1 We evaluated in vitro inhibitory effects of six types of antibiotic, aztreonam (AZT), cefamandole (CMD), cefmetazole (CMZ), cefotiam (CTM), flomoxef (FMOX) and latamoxef (LMOX), on platelet aggregation, using healthy volunteers' blood. Four types-FMOX, LMOX, CTM and CMD-inhibited, in concentration of 2500 ?g/ml, the secondary aggregation induced by 3.0 ?M adenosine diphosphate (ADP), and also inhibited the aggregation induced by 0.5 ?g/ml collagen. AZT in the same concentration, did not inhibit the aggregation induced by collagen, and it inhibited only ADP induced aggregation. CMZ, in the same concentration, inhibited neither of the two aggregations. 2 The inhibitory effects of the antibiotics on collagen- induced aggregation were dependent on the concen tration of respective antibiotics. When classified by the strength of inhibitory action, LMOX and FMOX were strong, followed by CTM and CMD. The action of AZT and CMZ was weak. In particular, LMOX showed a 32% inhibitory effect at concentration of 50 ?g/ml, a level near the blood concentration obtained with clinical usual dose. 3 No relationship was observed between inhibitory effects of antibiotics on ADP- or collagen-induced aggregation and the presence or absence of carboxyl group and/or N-methyltetrazolethiol group in the chemical structure.

Inhibitory effects of H2-receptor antagonists on platelet function in vitro

1999 ◽  
Vol 18 (8) ◽  
pp. 487-492 ◽  
Author(s):  
K Nakamura ◽  
H Kariyazono ◽  
T Shinkawal ◽  
T Yamaguchi ◽  
T Yamashita ◽  
...  
Keyword(s):  
Arachidonic Acid ◽  
Platelet Aggregation ◽  
Platelet Function ◽  
Chemical Structure ◽  
Adenosine Diphosphate ◽  
Imidazole Ring ◽  
Inhibitory Effects ◽  
Receptor Antagonists ◽  
Induced Aggregation

1 To evaluate in vitro inhibitory effects of four types of histamine H2-receptor antagonist (H2-receptor antagonists), famotidine, roxatidine, cimetidine and ranitidine, on platelet function, we examined aggregating potency and P-selectin levels with agonist-induced aggregation. Ranitidine and cimetidine inhibited, in concentration of 0.35 mM, the secondary aggregation induced by 5 pM adenosine diphosphate (ADP), the aggregation induced by 1,g/mL collagen and 3 gM arachidonic acid. All of H2-receptor antagonists inhibited, in concentration of 1.4 mm, the aggregation induced by ADP, collagen and arachidonic acid. Ranitidine and cimetidine reduced markedly, in same concentration, P-selectin levels after induction of aggregation by 5 gm ADP, 1 ig/xmL collagen and 3 gM arachidonic acid. When classified by the strength of inhibitory action, ranitidine and cimetidine were strong, followed by famotidine and roxatidine. 2 It is considered that inhibitory effects of H.-receptor antagonists on platelet function are weaker than those of acetylsalicylic acid (ASA), since ASA inhibited platelet aggregation in concentration of 100 MM. 3 No relationship was observed between inhibitory effects of H2-receptor antagonists on platelet aggregation induced by above agonists and the presence or absence of imidazole ring in the chemical structure.

Inhibition of Platelet Function by Antiarrhythmic Drugs, Verapamil and Disopyramide

1982 ◽  
Vol 47 (02) ◽  
pp. 150-153 ◽  
Author(s):  
P Han ◽  
C Boatwright ◽  
N G Ardlie
Keyword(s):  
Platelet Aggregation ◽  
Platelet Function ◽  
Antiarrhythmic Drugs ◽  
Adenosine Diphosphate ◽  
Inhibitory Effect ◽  
Second Phase ◽  
Ionophore A23187 ◽  
High Concentrations ◽  
Artery Disease

SummaryVarious cardiovascular drugs such as nitrates and propranolol, used in the treatment of coronary artery disease have been shown to have an antiplatelet effect. We have studied the in vitro effects of two antiarrhythmic drugs, verapamil and disopyramide, and have shown their inhibitory effect on platelet function. Verapamil, a calcium channel blocker, inhibited the second phase of platelet aggregation induced by adenosine diphosphate (ADP) and inhibited aggregation induced by collagen. Disopyramide similarly inhibited the second phase of platelet aggregation caused by ADP and aggregation induced by collagen. Either drug in synergism with propranolol inhibited ADP or collagen-induced platelet aggregation. Disopyramide at high concentrations inhibited arachidonic add whereas verapamil was without effect. Verapamil, but not disopyramide, inhibited aggregation induced by the ionophore A23187.

Opposite Effect of Lysine on Platelet Aggregation Induced by Arachidonate and by Other Aggregants

1982 ◽  
Vol 48 (01) ◽  
pp. 078-083 ◽  
Author(s):  
C Ts'ao ◽  
S J Hart ◽  
D V Krajewski ◽  
P G Sorensen
Keyword(s):  
Platelet Aggregation ◽  
Secondary Phase ◽  
Aminocaproic Acid ◽  
Adenosine Diphosphate ◽  
Inhibitory Effect ◽  
Human Platelets ◽  
Primary Phase ◽  
High Doses ◽  
The Many ◽  
Induced Aggregation

SummaryEarlier, we found that ε-aminocaproic acid (EACA) inhibited human platelet aggregation induced by adenosine diphosphate (ADP) and collagen, but not aggregation by arachidonic acid (AA). Since EACA is structurally similar to lysine, yet these two agents exhibit vast difference in their antifibrinolytic activities, we chose to study the effect of lysine on platelet aggregation. We used L-lysine-HCl in these studies because of its high solubility in aqueous solutions while causing no change in pH when added to human plasma. With lysine, we repeatedly found inhibition of ADP-, collagen- and ristocetin-induced aggregation, but potentiation of AA-induced aggregation. Both the inhibitory and potentiation effects were dose-dependent. Low doses of lysine inhibited the secondary phase of aggregation; high doses of it also inhibited the primary phase of aggregation. Potentiation of AA-induced aggregation was accompanied by increased release of serotonin and formation of malondialdehyde. These effects were not confined to human platelets; rat platelets were similarly affected. Platelets, exposed to lysine and then washed and resuspended in an artificial medium not containing lysine, remained hypersensitive to AA, but no longer showed decreased aggregation by collagen. Comparing the effects of lysine with equimolar concentrations of sucrose, EACA, and α-amino-n-butyric acid, we attribute the potent inhibitory effect of lysine to either the excess positive charge or H+ and C1− ions. The -NH2 group on the α-carbon on lysine appears to be the determining factor for the potentiation effect; the effect seems to be exerted on the cyclooxygenase level of AA metabolism. Lysine and other chemicals with platelet-affecting properties similar to lysine may be used as a tool for the study of the many aspects of a platelet aggregation reaction.

Mechanism of the Antiplatelet Action of Dipyridamole in Whole Blood: Modulation of Adenosine Concentration and Activity

1986 ◽  
Vol 55 (01) ◽  
pp. 012-018 ◽  
Author(s):  
Paolo Gresele ◽  
Jef Arnout ◽  
Hans Deckmyn ◽  
Jos Vermylen
Keyword(s):  
Platelet Aggregation ◽  
Adenosine Receptor ◽  
Whole Blood ◽  
Blood Cells ◽  
Inhibitory Action ◽  
Phosphodiesterase Inhibitor ◽  
Inhibitory Effect ◽  
Adenosine Concentration ◽  
Pharmacological Studies

SummaryDipyridamole inhibits platelet aggregation in whole blood at lower concentrations than in plasma. The blood cells responsible for increased effectiveness in blood are the erythrocytes. Using the impedance aggregometer we have carried out a series of pharmacological studies in vitro to elucidate the mechanism of action of dipyridamole in whole blood. Adenosine deaminase, an enzyme breaking down adenosine, reverses the inhibitory action of dipyridamole. Two different adenosine receptor antagonists, 5’-deoxy-5’-methylthioadenosine and theophylline, also partially neutralize the activity of dipyridamole in blood. Enprofylline, a phosphodiesterase inhibitor with almost no adenosine receptor antagonistic properties, potentiates the inhibition of platelet aggregation by dipyridamole. An inhibitory effect similar to that of dipyridamole can be obtained combining a pure adenosine uptake inhibitor (RE 102 BS) with a pure phosphodiesterase inhibitor (MX-MB 82 or enprofylline). Mixing the blood during preincubation with dipyridamole increases the degree of inhibition. Lowering the haematocrit slightly reduces the effectiveness.Although we did not carry out direct measurements of adenosine levels, the results of our pharmacological studies clearly show that dipyridamole inhibits platelet aggregation in whole blood by blocking the reuptake of adenosine formed from precursors released by red blood cells following microtrauma. Its slight phosphodiesterase inhibitory action potentiates the effects of adenosine on platelets.

Inhibition of Human Platelet Aggregation by the Proteolytic Effect of Streptokinase (SK). Role of the Factor VIII Related Antigen

1975 ◽  
Author(s):  
R. Castillo ◽  
S. Maragall ◽  
J. A. Guisasola ◽  
F. Casals ◽  
C. Ruiz ◽  
...  
Keyword(s):  
Platelet Aggregation ◽  
Factor Viii ◽  
Platelet Rich Plasma ◽  
Gel Filtration ◽  
Inhibitory Effect ◽  
Factor Viii Related Antigen ◽  
Human Factor Viii ◽  
Induced Aggregation

Defective ADP-induced platelet aggregation has been observed in patients treated with streptokinase. This same effect appears “in vitro” when adding SK to platelet rich plasma (PRP). Classic hemophilia and normal platelet poor plasmas (PPP) treated with SK inhibit the aggregation of washed platelets; plasmin-treated normal human serum also shows an inhibitory effect on platelet aggregation. However, von Willebrand SK-treated plasmas do not inhibit the aggregation of washed platelets. The same results appear when plasmas are previously treated with a rabbit antibody to human factor VIII.This confirms that the antiaggregating effect is mainly linked to the digested factor VIII related antigen.The inhibition of ADP-induced platelet aggregation has been proved in gel filtration-isolated and washed platelets from SK-treated PRP.Defective ristocetin-induced platelet aggregation has also been observed- This action does not appear in washed platelets from SK-treated PRP in presence of normal PPP, but it does in presence of SK-treated PPP, which suggests that the inhibition of the ristocetin-induced aggregation is due to the lack of factor VIII and not to the factor VIII-related products.Heparin, either “in vivo” or “in vitro”, has corrected the antiaggregating effect of SK.

Ticlopidine Selectively Inhibits Human Platelet Responses to Adenosine Diphosphate

1991 ◽  
Vol 66 (06) ◽  
pp. 694-699 ◽  
Author(s):  
Marco Cattaneo ◽  
Benjaporn Akkawat ◽  
Anna Lecchi ◽  
Claudio Cimminiello ◽  
Anna M Capitanio ◽  
...  
Keyword(s):  
Platelet Aggregation ◽  
Adenosine Diphosphate ◽  
Inhibitory Effect ◽  
Clot Retraction ◽  
Fibrinogen Binding ◽  
Low Concentrations ◽  
Binding Inhibition ◽  
High Concentrations ◽  
Formalin Fixed

SummaryPlatelet aggregation and fibrinogen binding were studied in 15 individuals before and 7 days after the oral administration of ticlopidine (250 mg b.i.d.). Ticlopidine significantly inhibited platelet aggregation induced by adenosine diphosphate (ADP), the endoperoxide analogue U46619, collagen or low concentrations of thrombin, but did not inhibit platelet aggregation induced by epinephrine or high concentrations of thrombin. Ticlopidine inhibited 125I-fibrinogen binding induced by ADP, U46619 or thrombin (1 U/ml). The ADP scavengers apyrase or CP/CPK, added in vitro to platelet suspensions obtained before ticlopidine, caused the same pattern of aggregation and 125I-fibrihogen binding inhibition as did ticlopidine. Ticlopidine did not inhibit further platelet aggregation and 125I-fibrinogen binding induced in the presence of ADP scavengers. After ticlopidine administration, thrombin or U46619, but not ADP, increased the binding rate of the anti-GPIIb/IIIa monoclonal antibody 7E3 to platelets. Ticlopidine inhibited clot retraction induced by reptilase plus ADP, but not that induced by thrombin or by reptilase plus epinephrine, and prevented the inhibitory effect of ADP, but not that of epinephrine, on the PGE1-induced increase in platelet cyclic AMP. The number of high- and low-affinity binding sites for 3H-ADP on formalin-fixed platelets and their K d were not modified by ticlopidine. These findings indicate that ticlopidine selectively inhibits platelet responses to ADP.

GUARANA (Paullinia cupana) INHIBITS AGGREGATION IN WHOLE BLOOD

1987 ◽  
Author(s):  
D A F Chamone ◽  
M Ivany-Silva ◽  
C Cassaro ◽  
G Bellotti ◽  
C Massumoto ◽  
...  
Keyword(s):  
Platelet Aggregation ◽  
Whole Blood ◽  
Ex Vivo ◽  
Platelet Rich Plasma ◽  
Oral Intake ◽  
Inhibitory Effect ◽  
Impedance Method ◽  
Paullinia Cupana ◽  
Induced Aggregation

Guarana, a methylxanthine obtained from the seeds of Paullinia cupana has been largely used in the Amazon region by native indians during centuries as stimulant. We evaluated the effect of guarana on ex-vivo and in vitro platelet aggregation induced by adenosine-5-diphosphate (ADP) in human and rat whole blood with an impedance (Chrono-Log, model 500) and in their platelet rich plasma (PRP) with an optical aggregometer (Chrono-Log, model 440). Ex-vivo studies were carried out after single oral intake of guarana. Seven healthy volunteers (5 male and 2 female) aged 19-26 years who had taken no drugs for 10 days before, ingested 8gm of crude powder of guarana. Blood samples were drawn before and 1 hour after guarana intake. We observed a significative inhibition of platelet aggregation in whole blood meanwhile PRP was un changed as compared to basal values. In vitro studies were performed in whole blood and PRP from human volunteers and male Wis-tar rats. The combined effect of guarana and adenosine was also studied. A control aggregation was always run with saline. The results demonstrated an inhibition statistically significative (p < 0.001) of platelet aggregation in whole blood. Differently from whole blood the PRP with the same concentration of guarana did not result in inhibition of ADP induced aggregation when eva luated with the impedance method. The blood incubation with adenosine and guarana resulted in synergistic inhibitory effect that was much more strinking in whole blood than in PRP. Guarana fails to inhibit aggregation of rat platelets.Our results demonstrate that guarana prevents platelet aggregation in whole blood which depends on red blood cells, probably involving adenosine.

scholarly journals Shear-induced platelet aggregation can be mediated by vWF released from platelets, as well as by exogenous large or unusually large vWF multimers, requires adenosine diphosphate, and is resistant to aspirin

Blood ◽  
1988 ◽  
Vol 71 (5) ◽  
pp. 1366-1374 ◽  
Author(s):  
JL Moake ◽  
NA Turner ◽  
NA Stathopoulos ◽  
L Nolasco ◽  
JD Hellums
Keyword(s):  
Shear Stress ◽  
Platelet Aggregation ◽  
Fluid Shear Stress ◽  
Thrombus Formation ◽  
Adenosine Diphosphate ◽  
Shear Stresses ◽  
Fluid Shear ◽  
Von Willebrand ◽  
Induced Aggregation

Abstract Fluid shear stress in arteries and arterioles partially obstructed by atherosclerosis or spasm may exceed the normal time-average level of 20 dyne/cm2. In vitro, at fluid shear stresses of 30 to 60 dyne/cm2 applied for 30 seconds, platelet aggregation occurs. At these shear stresses, either large or unusually large von Willebrand factor (vWF) multimers in the suspending fluid exogenous to the platelets mediates aggregation. Adenosine diphosphate (ADP) is also required and, in these experiments, was released from the platelets subjected to shear stress. At 120 dyne/cm2, the release of endogenous platelet vWF multimers can substitute for exogenous large or unusually large vWF forms in mediating aggregation. Endogenous released platelet vWF forms, as well as exogenous large or unusually large vWF multimers, must bind to both glycoproteins Ib and the IIb/IIIa complex to produce aggregation. Shear- induced aggregation is the result of shear stress alteration of platelet surfaces, rather than of shear effects on vWF multimers. It is mediated by either large plasma-type vWF multimers, endogenous released platelet vWF forms, or unusually large vWF multimers derived from endothelial cells, requires ADP, and is not inhibited significantly by aspirin. This type of aggregation may be important in platelet thrombus formation within narrowed arterial vessels, and may explain the limited therapeutic utility of aspirin in arterial thrombosis.

Lu 23051, A New Potent Inhibitor Of Platelet Aggregation

1981 ◽  
Author(s):  
H D Lehmann ◽  
J Gries ◽  
D Lenke
Keyword(s):  
Platelet Aggregation ◽  
Ex Vivo ◽  
Platelet Rich Plasma ◽  
Coronary Vessels ◽  
Inhibitory Effect ◽  
Spontaneously Hypertensive ◽  
Dependent Inhibition ◽  
Induced Aggregation

6- [p-(2-(Chiorpropionylamino)phenyl] -4.5-dihydro-5-methyl-3(2H)-pyridazinone, LU 23051, is primarily characterized by its strong inhibition of platelet aggregation under in vitro and in vivo conditions. In vitro there is a concentration-dependent inhibition of ADP and collagen induced aggregation in platelet rich plasma of man, rat and dog. The inhibitory concentration EC 33 % is 0.0010-0.030 mg/1 (man: ADP-0.030, col 1.-0.013 mg/l) depending on species and type of aggregation. When administered orally in ex vivo experiments on rats and dogs the substance is found to have a dose-dependent antiaggregatory effect in the range from 0.1-3.16 mg/kg. The ED 33 % is 0.27-0.63 mg/kg.-In addition after oral administration the substance has a good inhibitory effect in models being based on intravascular platelet aggregation. Thus, a dose of 1 mg/kg inhibits laser-induced aggregation in mesenteric venules of rats. Mortality after i.v. injection of collagen in mice is reduced by 50 % after a dose of 0.02 mg/kg. A dose of 0.039 mg/kg prolongs the bleeding time of rats by 50 %. The aggregation-inhibiting action is of long duration (0.1 mg/kg p.o.∼24 h). The substance does not interfere with clotting.Besides its effect on platelet aggregation LU 23051 acts as vasodilatator as well. Dilatation of coronary vessels by 100 % is seen in isolated guinea-pig hearts at a concentration of 0.1 mg/l. In spontaneously hypertensive rats the substance has an anti hypertensive effect. The ED 20 % is 0.36 mg/kg p.o.The combination of antiaggregatory and vasodilatatory effects opens up interesting aspects with respect to the pharmacotherapeutic use of the new substance

scholarly journals Macrostachyols A-D, oligostilbenes from Gnetum macrostachyum inhibited in vitro human platelet aggregation

2021 ◽  
Vol 10 (3) ◽  
pp. 339-343
Author(s):  
Serm Surapinit ◽  
Nuttakorn Baisaeng
Keyword(s):  
Platelet Aggregation ◽  
Human Platelet ◽  
Adenosine Diphosphate ◽  
Positive Control ◽  
Inhibitory Effects ◽  
Aggregation Assay ◽  
Human Platelet Aggregation ◽  
Platelet Aggregation Assay ◽  
Inhibitory Activities

Introduction: Gnetum macrostachyum is a known Thai medicinal plant as a source of bioactive oligostilbenes, which possess platelet inhibitory activities. The study aimed to evaluate the in vitro human platelet aggregation inhibitory activities of macrostachyols A-D (compounds 1-4) isolated from the roots of G. macrostachyum. Methods: The in vitro human platelet aggregation assay was assayed with a 96-well microtiter plate format. The well-known aggregating agents were used to investigate the possible mechanism of inhibition, including adenosine diphosphate (ADP), arachidonic acid (AA), thromboxane A2 analog (U-46619), collagen, thrombin, and thrombin receptor-activating peptide-6 (TRAP-6). Results: Compound 1 was more potent than ibuprofen (positive control) on the adenosine diphosphate- induced platelet aggregation assay (P < 0.05). Compound 3 was more potent than 1, 2, and 4 (P < 0.05), but all active oligostilbenes were less potent than the positive control (P < 0.05) on the arachidonic acid-induced platelet aggregation assay. The oligostilbenes 1, 2, 3, and 4 also displayed the inhibitory effects on the U-46619-induced platelet aggregation. The tetrameric stilbenes 1 was the only compound that exhibited inhibitory effects on thrombin-induced platelet aggregation without TRAP-6 mediated platelet aggregation. Conclusion: The findings revealed the inhibitory effects of oligostilbenes on human platelet aggregation through a target-specific experimental design. It suggests that oligostilbenes from this plant might be applied as antiplatelet aggregation agents in platelet hyperreactivity- related diseases.

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