Functional Significance of Mobile Receptors on Human Platelets
作者:
James White,
期刊:
Arteriosclerosis and Thrombosis: A Journal of Vascular Biology
(OVID Available online 1993)
卷期:
Volume 13,
issue 8
页码: 1236-1243
ISSN:1049-8834
年代: 1993
出版商: OVID
关键词: glycoprotein lib/Ilia;surface activation;suspension activation;open canalicular system;receptor/ligand complex translocation
数据来源: OVID
摘要:
Mobile receptors on surfaceand suspension-activated platelets bind a variety of specific and nonspecific antigens and particulates and clear them from the plasma membrane to channels of the open canalicular system (OCS). The present study examined the interaction of platelets with latex spherules of increasing size to identify the role of mobile receptors and binding sites in hemostatic physiology. Small latex spherules 0.09 to 3.13 /tm in average diameter were cleared from peripheral margins to central zones and the OCS on surface-activated platelets and from the surface membrane to the OCS of platelets in suspension. Larger spheres, 6.4 /tm in diameter, could not be moved across the membranes of solid phaseand fluid phase-activated platelets. Instead, platelets moved their surface membranes through the contact sites fixed on the surface of immobile spheres, bringing interior membranes of the OCS channels to the latex. This change, in which mobile membranes move through fixed contact sites rather than mobile receptor complexes moving across plasma membranes, results in evagination of almost all OCS channels on large latex spherules. A similar mechanism may be involved in the interaction of platelets with relatively flat surfaces, such as denuded subendothelium.
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