Thrombin induced platelet aggregation

B-NOD is a new NO donor compound. It has a chemical NO-releasing group similar to that of NTG, however, it releases NO in vitro and in vivo. After administration of B-NOD in vivo its activity persists for more than 7 h. In vitro, the release of NO from B-NOD was augmented by the presence ofliving cells (blood platelets). B-NOD increased cGMP levels and prevented thrombin-induced platelet aggregation in vitro in the same manner as SNP. In vivo, administration of B-NOD in rabbits did not cause a fall in blood pressure or an increase in heart rate [97]. 

It is also possible that vitamin E can nullify some of the main adverse effects of oestrogen on blood platelets. Administration of ethynyloestradiol to female rats increased lipid synthesis, mainly lanosterol, and thrombin-induced platelet aggregation. Treatment of the rats with a-tocopheryl acetate depressed the enhanced lipid synthesis and aggregation induced by the oestrogen. In vitro, too, platelet aggregation was enhanced by the addition of lanosterol, and this response was almost completely antagonised by preincubation with a-tocopheryl acetate [145]. 

Normal thrombin-induced platelet aggregation increase in circulating number of white blood cells TSP-1 is involved in normal lung homeostasis (Lawler etal. 1998). 

Ristocetin and thrombin-induced platelet aggregation at physiological shear rates Differential roles for GPIb and GPIIb-IIIa receptor... 

Williams, J. C., Forster, L. A., Tull, S. P., Wong, M., Bevan, R. J., and Ferns, G. A. (1997) Dietary vitamin E supplementation inhibits thrombin-induced platelet aggregation, but not monocyte adhesiveness, in patients with hypercholesterolaemia. Int J Exp Pathol 78,259-66. 

As shown in "Figs. (34) and (35) ", among the six saponins tested, only ginsenoside Rgi "Fig. (36)" inhibited adrenaline- and thrombin-induced platelet aggregation and 5-HT release dose-dependently. 

Xu and Feng investigated the effects of racemic butylphthalide and its enantionmers (S-, 32) and (/ -, 31) on platelet aggregation in rat PRP [300]. Both enantiomers and the racemic mixture (3-100 pM) dose-dependently inhibited platelet aggregation in rat PRP induced by ADP, collagen and AA, but did not affect thrombin-induced platelet aggregation. Furthermore, the S-enantiomer 32 and racemic mixture (10-100 pM) increased intracellular cAMP concentration in a dose-dependent manner. On the other... 

In addition, licochalcones A and B inhibited thrombin-induced platelet aggregation, dose-dependently "Fig. (40)". Moreover, licochalcones A and B inhibited calcium ionophore-induced production of LTs B4 and C4... 

In human platelets, the compound andrographolide inhibited platelet-activating-factor-induced aggregation in a dose-dependent manner (Amroyan et al. 1999). In mouse platelets, a standardized aqueous extract of andrographis, and the compounds andrographolide and 14-deoxy-ll,12-di-dehydroandrographolide inhibited thrombin-induced platelet aggregation in a dose-dependent manner (Thisoda et al. 2006). 

The compound ar-tumerone was shown to inhibit in vitro platelet aggregation induced by collagen or arachidonic acid but had no effect on platelet-activating factor or thrombin-induced platelet aggregation (Lee 2006). 

An aqueous extract of alfalfa inhibited ADP- and collagen-induced human platelet aggregation but had no effect on arachadonic acid- or thrombin-induced platelet aggregation. Alfalfa inhibited thromboxane B2 synthesis induced by ADP or collagen, and whole blood aggregation induced by collagen (Pierre et al. 2005). 

A partially purified fraction of Indian madder inhibited PAF-induced, but not thrombin-induced, platelet aggregation in rabbit platelets (Tripathi et al. 1993). 

In pig blood platelets, application of phenolic compounds, including fr ns-3,3, 5,5 -tetrahydroxy-4 -metho-xystilbene and yuccaols A and C, as a pretreatment slightly reduced platelet aggregation stimulated by ADP. With thrombin-induced platelet aggregation, the selected compounds exhibited significant inhibition of aggregation (Olas et al. 2002). 

Hemostatic and mild hypotensive activities have been reported (bradly). In an in vitro study, the aqueous extract of U. dioica dose dependently inhibited thrombin-induced platelet aggregation. The observed effect has been attributed to the flavonoid constituents of the extract. The hypotensive effects of U. dioica extracts (aqueous and methanohc, in vivo and in isolated organs) have also been reported by more than one group and the mechanism of action is suggested to be through vasodilation mediated by nitric oxide release, potassium channel opening, and negative inotropic action. ... 

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