title: Rhythms of isolated platelet glutathione, aging, and the internal evolution of species.
abstract: Platelet integrity upon reinfusion after storage for varying periods of time constitutes a clinical problem requiring chronobiologic study. For such a study, total glutathione (GSH) served as an index. Blood from healthy volunteers drawn at 0800 was mixed with citrate-citric acid-dextrose (CCD) and centrifuged at 100g to obtain platelet-rich plasma (PRP), transferred to sterile containers, and maintained under ordinary laboratory conditions at room temperature in casually alternating light (L) and darkness (D), in LD 16.8, in continuous light (LL), or in continuous darkness (DD). In 5-ml aliquots of PRP mixed with 500 microliter of 0.34 M EDTA and recentrifuged for 15 min at 200g, a circadian rhythm of GSH per 10(9) platelets was found. The fit to 4-hr data of a linear trend and a 24-hr cosine yields similar acrophases (phi) under the various conditions investigated. With 360 degrees = 24 hr and with 95% limits in parentheses, the acrophases for PRP from a male donor stored in LD, LL, or DD are -64 degrees (-20 degrees, -107 degrees), -67 degrees (-28 degrees, -106 degrees), and -74 degrees (-35 degrees, -112 degrees), respectively. The corresponding values for platelets from a female donor in LD, LL, and DD are -49 degrees (-17 degrees, -80 degrees), -82 degrees (-50 degrees, -113 degrees), and -68 degrees (-29 degrees, -107 degrees), respectively. Six of six best-fitting circadian periods are longer than 24 hr, a result in keeping with a possibly free-running circadian rhythm.(ABSTRACT TRUNCATED AT 250 WORDS)
mesh_terms: D005075:Biological Evolution; D001792:Blood Platelets / Q000032:analysis*; D002940:Circadian Rhythm; D003469:Culture; D005260:Female; D005978:Glutathione / Q000097:blood*; D006801:Humans; D066298:In Vitro Techniques; D008297:Male; D010507:Periodicity; D013997:Time Factors
chemical_list: D005978:Glutathione