The Effect of a Medicinal Chinese Herb on Platelet Function

1982 ◽  
Vol 48 (03) ◽  
pp. 301-306 ◽  
Author(s):  
Z Wang ◽  
J M Roberts ◽  
P G Grant ◽  
R W Colman ◽  
A D Schreiber

SummaryWe investigated the effect of the Chinese herb Injectio Salvia Miltiorrhizae (ISM) on human platelet function in vitro. ISM inhibited platelet aggregation and serotonin release induced by either ADP or epinephrine in a dose dependent manner. This effect of ISM was observed with both gel-filtered platelets (ID50 = 8–30 μg ISM/ml gel-filtered platelets) and platelets in plasma (ID50 = 400–900 μg ISM/ml of platelet-rich plasma). The active molecule(s) in ISM was heat stable, resistant to acid, base and proteolysis and fractionated on Sephadex 6-25 at MW ~ 280. ISM did not interact with the platelet α-adrenergic receptor, but increased cAMP in intact platelets. The results are consistent with the concept that ISM inhibition of platelet aggregation and release is mediated by an increase in platelet cAMP. The exact mechanism whereby ISM increases platelet cAMP appears to be that of inhibition of cyclic AMP phosphodiesterase. The effect of ISM on platelet function is one mechanism which might explain the therapeutic effect of ISM in experimental and clinical coronary artery disease.

1971 ◽  
Vol 26 (03) ◽  
pp. 455-466 ◽  
Author(s):  
R. B Davis ◽  
G. C Holtz

SummaryThe effects of lead on blood platelet function and ultrastructure have been investigated. Lead acetate was injected intravenously in 27 rats and was added to rat and human platelet rich plasma in vitro. In vitro studies showed that concentrations of 2.5 × 10-3 M lead acetate reduced or blocked aggregation of rat and human platelets by adenosine diphosphate, collagen, and thrombin. Radioactive serotonin release from human platelets was inhibited by 10-4 M lead acetate. One hour after the injection of lead, platelet aggregation by thrombin was reduced, but platelet aggregation by adenosine diphosphate and collagen showed little change. Three days after lead, aggregation of platelets by collagen and thrombin was blocked and aggregation by adenosine diphosphate reduced. Thrombocytopenia was present 4 days after intravenous lead acetate. Electron micrographs of platelets showed that the mean number of mitochondria per platelet was increased, whereas alpha granules were reduced. Dense bodies were not significantly changed. Lead acetate affects platelet function in concentrations reported in human bone marrow in lead poisoning, and may relate to the binding of free sulfhydryl groups by lead.


2019 ◽  
Vol 8 (3) ◽  
pp. 4-10 ◽  
Author(s):  
N. N. Petrishchev ◽  
M. A. Galkin ◽  
T. G. Grishacheva ◽  
I. N. Dementjeva ◽  
S. G. Chefu

The goal of the study is to evaluate the effect of Radachlorin (OOO “RADA-PHARMA”, Russia) (RC) on platelet aggregation in ex vivo and in vivo experiments. The experiments were conducted on male Wistar rats. Platelet aggregation activity was determined in platelet-rich plasma (PRP) using a turbidimetric method and the aggregation inducer was ADP at a final concentration of 1.25 μM. PRP samples containing RC were irradiated with ALOD-Granat laser device (OOO “Alkom Medika”, Russia) at 662 nm wavelength with 0.05 W/cm2 power density. After a 5-minute incubation of PRP with RC in the dark, dose-dependent inhibition of platelet aggregation was observed. Laser irradiation (12.5 J/cm2 and, especially, 25 J/cm2) increased the inhibitory effect of RC. 3 hours after intravenous administration of RC, the rate and intensity of platelets aggregation did not change, while disaggregation slowed down significantly. Irradiation at a dose of 5 J/cm2 did not affect the platelets aggregation kinetics, and disaggregation slowed down even more at 10 J/cm2, and at 20 J/cm2 the rate and intensity of platelets aggregation decreased, and no disaggregation occurred.In vitro, RC inhibited the ADP-induced platelet aggregation in rats in a dose-dependent manner; after laser irradiation, this effect was enhanced significantly. The effect of RC on circulating platelets leads to a change in their functional state, which manifests in slowing down the disaggregation after exposure to ADP. After laser irradiation (10 J/cm2 and, especially, 20 J/cm2), the severity of the functional changes increases. The role of decreasing the disaggregation activity of platelets in the mechanism of vascular thrombosis in the affected area of photodynamic therapy (PDT) is discussed.


1977 ◽  
Author(s):  
K. Subbarao ◽  
F. Forestier

Physiological diamines and polyamines occur in high concentrations in various parts of animal tissues. These amines are known to interact with and stabilize nucleic acids, membranes and ribosomes (Tabor and Tabor, Pharmac. Rev., 16, 245). The effect of putrescine, cadaverine, spermidine and spermine on platelet function is not yet fully explored. We studied the effect of these reagents on in vitro aggregation of human platelet rich plasma (PRP) induced by the addition of ADP, thrombin, collagen and serotonin. Cadaverine, spermidine and spermine at concentrations from 2-5 μM strongly inhibited the aggregation of platelets and the [14C]-serotonin release reaction induced by ADP and thrombin in a concentration dependent manner, but did not show any effect on aggregation induced by other agents. Putrescine, on the other hand, failed to produce any effect on the aggregation of platelets and [14C]-serotonin release reaction. Studies on the binding of purified human thrombin treated with [14C]-diisopropylfluoro-phosphate (DFP) to washed human platelets indicated that cadaverine (1-5 μmoles) increased the binding of total [14C]-DFP-thrombin to platelets by 30%. The data suggest that the alteration of platelet function by diamines and polyamines was probably achieved by their binding to platelet membranes.


1977 ◽  
Author(s):  
A. C. Carvalho ◽  
R. W. Colman ◽  
R. Vaillancourt ◽  
R. Cabrai ◽  
R. Anaya

Diazepam (Valium) is one of the most prescribed medications in the world. Patients on Diazepam may need platelet function evaluation. Therefore, a study of its effect on both in vivo and in vitro platelet function was undertaken in 8 normal volunteers. Diazepam (10–40μg/ml) was incubated in vitro with platelet rich plasma (250,000/μl) at intervals of 15, 30, 60, 120, and 240 minutes followed by determination of platelet aggregation and 14C-serotonin release. Fifty percent inhibition of platelet aggregation and release by Diazepam was obtained at 1 hr with epinephrine (p<0.01) and at 2 hrs with ADP (p<0.01), but no significant effect was noted with collagen. The Diazepam inhibitory effect on platelet aggregation and release was overcome by high concentrations of aggregating agents, suggesting that its primary effect is not mediated by inhibition of prostaglandin synthesis.Following oral ingestion of 5mg of Diazepam, platelet aggregation and 14C-serotonin release were determined serially (2, 4, 8, 12, 24, and 48 hours) in the 8 normal subjects. After 8 hours, Diazepam inhibited ADP-induced aggregation and release by 39% (p<0.01) and epinephrine by 50% (p<0.01). No significant inhibition of collagen was observed. Forty-eight hours after Diazepam intake, platelet function returned to normal in all subjects.Our data show that Diazepam impairs both platelet aggregation and release in vitro and in vivo. Although the effect of Diazepam on in vivo hemostasis is still uncertain, our results suggest caution in the interpretation of platelet function testing in patients on this drug.


1996 ◽  
Vol 76 (01) ◽  
pp. 088-093 ◽  
Author(s):  
Hanne Berg Ravn ◽  
Henrik Vissinger ◽  
Steen Dalby Kristensen ◽  
Steen Elkjcer Husted

SummaryThe in vitro effect of magnesium (Mg) on platelet aggregation and platelet release function was evaluated in healthy volunteers. Platelet aggregation was induced with collagen, ADP, or thrombin after incubation of the sample with saline or increasing concentrations of magnesium sulphate (MgSO4) (0.5-8.0 mM). Mg showed a dose-dependent inhibition of platelet aggregation in whole blood, platelet rich plasma and washed platelets. An antiaggregatory effect was also present with low Mg concentrations. Statistically significant inhibition of the mean aggregation response was obtained in 83% of the different media and agonists tested following the addition of 1.0 mM Mg. The remaining 17% were significantly inhibited with the addition of 2.0 mM Mg. The platelet synthesis of thromboxane A2 and release of beta-thrombo-globulin were also inhibited by Mg, in a dose-dependent manner. In order to evaluate if any of these effects were modified by conventional antithrombotic treatment with low-dose acetylsalicylic acid (ASA), volunteers were asked to meet on two consecutive days. On day 2 the participants were given 300 mg ASA orally, one hour prior to blood sampling. The Mg mediated effects were present independent of this pretreatment with ASA. Following stimulation with collagen a synergistic effect of Mg and ASA was demonstrated on platelet aggregation. The platelet inhibiting effect demonstrated in this study may in part explain the beneficial effect of Mg infusion in some patients with acute myocardial infarction. The effect of Mg infusion, given alone or administered simultaneously with ASA, should also be evaluated in other arterial thrombotic disease states.


1994 ◽  
Vol 72 (02) ◽  
pp. 309-312 ◽  
Author(s):  
R Berkels ◽  
W Klaus ◽  
M Boiler ◽  
R Rösen

SummaryThe in vitro effect of nifedipine, a calcium channel blocker of the dihydropyridine (DHP) type, on platelet aggregation was reinvestigated considering especially the capability of platelets to form endogenous nitric oxide (NO). We studied the dose-dependent antiaggregatory property of nifedipine in porcine platelet rich plasma. Aggregation was stimulated by collagen (7.5 ¼g/ml). Nifedipine inhibited collagen-induced platelet aggregation with an IC50 of 380 nmol/1. The antiaggregatory effect of nifedipine could be significantly diminished by N-nitro-L-arginine (NNA) in a concentration dependent manner, whereas oxy haemoglobin (4 ¼M), a NO scavenger, totally abolished the effect of nifedipine. L-Arginine, the precursor of NO, dose-dependently inhibited the collagen-induced platelet aggregation but did not potentiate the effects of nifedipine. Therefore, we propose that in platelet rich plasma the nifedipine induced inhibition of platelet aggregation is mediated by NO, a potent endogenous inhibitor of aggregation. We could confirm this hypothesis by measuring NO directly with a specific electrode.


1987 ◽  
Author(s):  
Y Ikeda ◽  
M Murata ◽  
Y Araki ◽  
M Yamamoto ◽  
K Watanabe ◽  
...  

It is well known that human platelets can aggregate in vitro under certain shear stress without adding aggregating inducers. However, the mechanism of this shear-induced platelet aggregation has not been clarified yet. In this paper, we have investigated the role of fibrinogen and GP IIb/IIIa in shear-induced platelet aggregation. Citrated human platelet-rich plasma (PRP) was subjected to controlled shear stress levels in a polycarbonate cone and plate viscometer at 37°C for 2 minutes. After shearing the particle count was measured by an electronic particle counter. Particles with sizes from 3 to 20 μ cum were considered as single platelets. In unsheared PRP most of the particles were single platelets, but platelet doublets and platelet fragments larger than 3 μ cum were also counted. After exposure to shear rate of 3,600 - 9,000 sec−1 , the particle counts were decreased in a shear rate dependent manner, while LDH leakage from platelets was not significantly increased and 3H-serotonin release was 2-7%. Scanning electronmicroscopy clearly showed the presence of large platelet aggregates when the particle counts were decreased. Platelets from two patients with thrombasthenia and one patient with afibrinogenemia, however, failed to aggregate at a shear rate of 9,000 sec−1. Shear-induced aggregation was inhibited by monoclonal antibody to GPIIb/IIIa (1 μg/ml) and synthetic peptide, Arg-Gly-Asp-Ser, (1 mM). When fibrinogen was added to PRP from a patient with afibrinogenemia, shear-induced aggregation became evident as seen in normal platelets. Apyrase and hirudin showed no effect on shear-induced aggregation. Indomethacin (100 μM) and TXA2 synthetase inhibitor, OKY-046 (100 μM) markedly inhibited aggregation, while TXA2 competitive inhibitor, ONO-3708 (100 μM) exhibited only partial inhibition.Our results indicate that binding of fibrinogen to GPIIb/lIIa is also crucial for shear-induced platelet aggregation and that the exposure of fibrinogen receptor on GPIIb/IIIa may partially depend upon TXA2 synthesis in platelets.


2017 ◽  
Vol 2017 ◽  
pp. 1-6 ◽  
Author(s):  
Yun-Xiang Zhang ◽  
Ting-Ting Yang ◽  
Liu Xia ◽  
Wei-Fen Zhang ◽  
Jia-Fu Wang ◽  
...  

Platelet hyperactivity plays an important role in arterial thrombosis and atherosclerosis. The present study was aimed to investigate the effects of different extracts of propolis and components of flavonoids on platelet aggregation. Platelet-rich plasma was prepared and incubated in vitro with different concentrations of the tested extracts and components of flavonoids. Platelets aggregation was induced by different agonists including adenosine diphosphate (ADP, 10 μM), thrombin receptor activator peptide (TRAP, 50 μM), and collagen (5 μg/mL). At 25 mg/L to 300 mg/mL, the water extract propolis (WEP) inhibited three agonists-induced platelet aggregations in a dose-dependent manner. The flavonoids isolated from the propolis also showed markedly inhibited platelet aggregation induced by collagen, ADP, and TRAP, respectively. The components including caffeic acid phenethyl ester (CAPE), galangin, apigenin, quercetin, kaempferol, ferulic acid, rutin, chrysin, pinostrobin, and pinocembrin and their abilities of inhibiting platelet aggregation were studied. It was concluded that propolis had an antiplatelet action in which flavonoids were mainly implicated.


1973 ◽  
Vol 30 (02) ◽  
pp. 315-326
Author(s):  
J. Heinz Joist ◽  
Jean-Pierre Cazenave ◽  
J. Fraser Mustard

SummarySodium pentobarbital (SPB) and three other barbituric acid derivatives were found to inhibit platelet function in vitro. SPB had no effect on the primary response to ADP of platelets in platelet-rich plasma (PRP) or washed platelets but inhibited secondary aggregation induced by ADP in human PRP. The drug inhibited both phases of aggregation induced by epinephrine. SPB suppressed aggregation and the release reaction induced by collagen or low concentrations of thrombin, and platelet adherence to collagen-coated glass tubes. The inhibition by SPB of platelet aggregation was readily reversible and isotopically labeled SPB did not become firmly bound to platelets. No inhibitory effect on platelet aggregation induced by ADP, collagen, or thrombin could be detected in PRP obtained from rabbits after induction of SPB-anesthesia.


1995 ◽  
Vol 73 (03) ◽  
pp. 472-477 ◽  
Author(s):  
H R Lijnen ◽  
B Van Hoef ◽  
D Collen

SummaryThe interactions of recombinant staphylokinase (SakSTAR) with human platelets were investigated in a buffer milieu, in a human plasma milieu in vitro, and in plasma from patients with acute myocardial infarction (AMI) treated with SakSTAR.In a buffer milieu, the activation rate of plasminogen by SakSTAR or streptokinase (SK) was not significantly altered by addition of platelets. Specific binding of SakSTAR or SK to either resting or thrombin- activated platelets was very low. ADP-induced or collagen-induced platelet aggregation in platelet-rich plasma (PRP) was 94 ± 2.7% or 101 ± 1.7% of control in the presence of 0.1 to 20 μM SakSTAR, with corresponding values of 95 ± 2.8% or 90 ± 4.6% of control in the presence of 0.1 to 4 μM SK. No effects were observed on platelet disaggregation. ATP secretion following collagen-induced platelet aggregation was 4.3 ± 0.26 μM for SakSTAR (at concentrations of 0.1 to 20 μM) and 4.4 ± 0.35 μM for SK (at concentrations of 0.1 to 4 μM), as compared to 3.4 ± 0.70 μM in the absence of plasminogen activator.Fifty % lysis in 2 h (C50) of 60 μl 125I-fibrin labeled platelet-poor plasma (PPP) clots prepared from normal plasma or from plasma of patients with Glanzmann thrombasthenia and immersed in 0.5 ml normal plasma, was obtained with 12 or 16 nM SakSTAR and with 49 or 40 nM SK, respectively. C50 values for lysis of 60 μl PRP clots prepared from normal or patient plasma were also comparable for SakSTAR (19 or 21 nM), whereas SK was 2-fold more potent toward PRP clots prepared from Glanzmann plasma as compared to normal plasma (C50 of 130 versus 270 nM).No significant effect of SakSTAR on platelet function was observed in plasma from patients with AMI treated with SakSTAR, as revealed by unaltered platelet count, platelet aggregation and ATP secretion.Thus, no effects of high SakSTAR concentrations were observed on human platelets in vitro, nor of therapeutic SakSTAR concentrations on platelet function in plasma.


Sign in / Sign up

Export Citation Format

Share Document