Search for the Lesion(s) of Platelet Storage.
Abstract
Techiniques were developed for: (1) measuring the lipase activities of human platelets by patterns of release of endogenous fatty acids, as opposed to the release of fatty acids from model substrates; (2) measuring the phospholipase A2 activity of human platelets by the release of arachidonic acid as well as by oxygen consumption; (3) assessing the metabolism of platelets and arteries in vivo. Primate platelets and arteries are incapable of converting lanosterol to cholesterol in vivo; (4) isolating alpha granules and mitochondria from platelet homogenates. Success was attributed to two departures; homogenization by cavitation forces developed by explosive decompression, and the elimination of a preliminary centrifugation to remove debris prior to ultracentifugation. Using this technique, platelet factor XIII was shown to be a cytoplasmic component whereas fibrinogen and platelet factor 4 are concentrated in alpha granules, and platelet factor 3, although present in all fractions was on the basis of phospholipid content, highest in the alpha granule and soluble fractions; (5) measuring the function of mitochondria in the intact human platelet by exposing the platelets to graded decrements of osmolarity. Human platelets are capable of tight respiratory coupling, and are otherwise similar to other mammalian platelets in their metabolic responses in vitro.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 1975
- Accession Number
- ADA053074
Entities
People
- Phin Cohen
Organizations
- Harvard T.H. Chan School of Public Health