In vitro effects of gelatin solutions on platelet function: a comparison with hydroxyethyl starch solutions

Three substances widely used as vasoactive drugs are known to have an inhibiting effect on platelet aggregation ‘in vitro’. We investigated the changes induced on thrombelastogram, routine clotting tests, euglobulin lysis time (ELT), platelet count, aggregation, and adhesiveness by i, v. administration of these drugs to man. The same indices were also studied ‘in vitro’ by adding comparable concentrations of the substances to human blood or plasma.Aminophilline did not produce any significant variation in ADP-or collagen-induced aggregation either ‘in vitro’ (50 to 200 μg/ml) or ‘in vivo’ (240 mg). A trend to disaggregation was seen only in a few cases. Shorter ELT were found 30 and 120 minutes after injection.A papaverine derivative (Metaverinum, 150 mg) showed a similar ‘in vivo’ pattern: minor changes in platelet function tests and a moderate activation of fibrinolysis were seen. The drug acted ‘in vitro’ as a powerful inhibitor of aggregation (from 30 µg/ml)while fibrinolysis was only activated at the highest concentration (120 µg/ml).Bencyclan, capable of inhibiting platelet function ‘in vitro’ at very low concentrations (0.25µM) did not show similar effects ‘in vivo’ (50 mg) apart from a reduced platelet adhesiveness to glass.

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In vitro effects of cobalt and chromium nanoparticles on human platelet function

Nanotoxicology ◽

10.1080/17435390.2020.1841845 ◽

2020 ◽

pp. 1-14

Author(s):

Dominik Taterra ◽

Bendik Skinningsrud ◽

Przemysław A. Pękala ◽

Iwona M. Tomaszewska ◽

Krzysztof Marycz ◽

...

Keyword(s):

Platelet Function ◽

Human Platelet ◽

In Vitro Effects ◽

Chromium Nanoparticles

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Inhibition of platelet function by organic nitrate vasodilators

Blood ◽

10.1182/blood.v55.4.649.bloodjournal554649 ◽

1980 ◽

Vol 55 (4) ◽

pp. 649-654

Author(s):

AI Schafer ◽

RW Alexander ◽

RI Handin

Keyword(s):

Myocardial Ischemia ◽

Platelet Function ◽

Coronary Circulation ◽

Platelet Reactivity ◽

Inhibitory Effect ◽

Organic Nitrate ◽

Artery Disease ◽

In Vitro Effects ◽

External Calcium

There is evidence that platelet activation in the coronary circulation may be important in the pathogenesis of myocardial ischemia. Since organic nitrate vasodilators are commonly used in coronary artery disease, we have studied the in vitro effects of these drugs on platelet function. Nitroglycerin, isosorbide dinitrate, and their biotransformation product, inorganic nitrite, inhibited platelet aggregation with collagen, epinephrine, arachidonate, and ionophore, and blocked both primary and secondary aggregation in response to ADP. Nitroglycerin was studied in more detail. Its inhibitory effect was reversible and not dependent on external calcium concentration. It inhibited arachidonic acid oxygenation as measured by the arachidonate- induced oxygen burst and malonaldehyde production. These effects were not due to an increase in intracellular cyclic AMP. This unusual generalized inhibition of platelet function by nitroglycerin possibly contributes to its beneficial effect in myocardial ischemia in part by attenuating platelet reactivity in the coronary circulation.

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