A new method for studying platelets based on low-angle light scattering has been applied to studies in experimental toxicology and clinical pathology, using animal and human platelets. Index EC50for ADP within control groups was estimated to be in the range of 100–180 nmol l–1(healthy men, rabbits, rats). The refractory state of platelets was obtained by use ADP or ATP concentrations that just caused platelet activation. The time constant and the half-cycle of the refractory state of platelets were calculated. Kinetic parameters of platelet aggregation at interference of hemostasis (rabbit) and the influence of the age factors on the aggregation indices of platelets (rat) were studied. The method of low-angle light scattering was used as a diagnostic tool in experimental low-level intoxication by organophosphates and for interpretation of the pathogenesis of delayed effects. In human patients with ischemic heart disease or with prosthetic heart valves, significant changes in the functional state of platelets were observed. A model for cooperative binding of receptors with ligands on platelets from pregnant women with preeclampsia was developed.

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A low-angle light scattering technique, which has been applied previously to studies of blood platelets and Ehrlich ascite tumor cells, revealed differences in the dynamics of necrotic and apoptotic red blood cell death. Under hypotonic loading or in ammonia medium, red blood cells (RBC) swelled to a critical size (diameter approximately 13 µm) prior to hemolysis (necrosis). Under acidic loading, hemolysis occurred with less pronounced swelling of cells (diameter approximately 10 µm). Apoptosis induced by a calcium ionophore resulted in initial formation of echinocytes, followed by development of rounded red blood cells with uneven membrane, capable of agglomeration. In such a way, RBC aggregation can precede the final stages of the RBC apoptosis when small cellular fragments are generated. On the basis of erythrograms of the cells hemolysing in ammonia medium, the echinocytic (preapoptotic) and stomatocytic (prenecrotic) RBC were discerned due to the very high resistance of apoptotic RBC to osmotic (ammonia) loading.

A new method for studying platelets based on low-angle light scattering has previously revealed that platelets taken from pregnant women with preeclampsia are hypersensitive to ADP, with aggregation developing at concentrations of 7–15 nmol l−1. The method has been applied to further studies in experimental toxicology and clinical pathology. Toxicological experiments with fluoroacetate (FA), an inhibitor of TCA cycle, showed that the platelet hypersensitivity could also be caused by energy depletion. In modeling experiments, the low-angle light scattering method was applied to assessment of potential corrective agents of the pathological states related to hypersensitivity of platelets. Sodium glutamate (SG) was shown to be a potent antiaggregantin vitro, and subsequentin vivostudies demonstrated that SG can apparently serve as anaplerotic agent and normalize the platelet status of rats intoxicated with FA. Donators of nitric oxide (NO), such as isosorbide-5′-dinitrate, can also normalizein vitrothe hypersensitive status of platelets taken from the patients with preeclampsia.