Platelets from eclampsia patients have reduced membrane microviscosity and lower activities of the signalling enzymes

Koner, Bidhan C. ; Jain, Madhu ; Dash, Debabrata (1998) Platelets from eclampsia patients have reduced membrane microviscosity and lower activities of the signalling enzymes International Journal of Biochemistry & Cell Biology, 30 (1). pp. 147-154. ISSN 1357-2725

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Official URL: http://www.sciencedirect.com/science/article/pii/S...

Related URL: http://dx.doi.org/10.1016/S1357-2725(97)00072-1

Abstract

It has been shown that platelets from patients suffering from eclampsia are hyporesponsive to stimulation by agonists like thrombin and ADP. Although platelet hyporeactivity contributes to the pathogenesis of the disease process, the cause for this is still not known. Platelet aggregation and secretion are membrane-based phenomena initiated by the processes of cell signalling. Hence, to understand the mechanisms underlying platelet hyporeactivity in eclampsia, membrane microviscosity and activities of the signalling enzymes were measured in human platelets stimulated with thrombin. Membrane fluidity was determined from the steady-state fluorescence anisotropy of diphenylhexatriene incorporated in cell membranes. Activities of phospholipase C and protein kinase C in stimulated platelets were assessed from the extents of phosphatidic acid generation and pleckstrin phosphorylation, respectively. Platelet membrane microviscosity in eclampsia (2.3±0.2 SEM, n=5) was significantly lower (P<0.05) than that in the matched gravid control subjects (3.1±0.2, n=4). In eclampsia, generation of phosphatidic acid and phosphorylation of pleckstrin were decreased by 25% (P<0.05, n=3) and 35% (P<0.05, n=3), respectively, after 60 sec of platelet stimulation. It was concluded that the hyporeactive platelets obtained from eclampsia have more fluid membranes and diminished activities of phospholipase C and protein kinase C. In summary, this study shows that alterations in membrane fluidity and activities of the signalling enzymes (phospholipase C and protein kinase C) may contribute to the diminished platelet responsiveness observed in the eclamptic condition.

Item Type:Article
Source:Copyright of this article belongs to Elsevier Science.
Keywords:Membrane Fluidity; Platelet Activation; Phospholipase C; Protein Kinase C; Eclampsia
ID Code:101360
Deposited On:04 Feb 2017 17:20
Last Modified:04 Feb 2017 17:20

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