Premium
AGE‐RELATED CHANGES IN PLATELET MICROVISCOSITY AND AGGREGATION IN RATS
Author(s) -
Hossain Shahdat,
Hashimoto Michio,
Masumura Sumio
Publication year - 1999
Publication title -
clinical and experimental pharmacology and physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.752
H-Index - 103
eISSN - 1440-1681
pISSN - 0305-1870
DOI - 10.1046/j.1440-1681.1999.03053.x
Subject(s) - microviscosity , chemistry , platelet , fluorescence anisotropy , phospholipid , polyunsaturated fatty acid , arachidonic acid , anisotropy , thrombin , biophysics , medicine , endocrinology , biochemistry , biology , fatty acid , physics , quantum mechanics , membrane , enzyme
1. To study possible changes in platelet microviscosity in aged animals, 1,6‐diphenyl‐1,3,5‐hexatriene (DPH) was used as a non‐polar probe embedded in thrice‐washed platelets from young, adult and aged rats. With the known values of maximum limiting anisotropy and the structural parameter of DPH and by estimating the steady state of fluorescence anisotropy and the average fluorescence of lifetime, we applied the Perrin equation to calculate the microviscosity. 2. We measured platelet aggregation, platelet lipids and platelet polyunsaturated fatty acids to determine any causal relationship between these parameters. Platelet aggregation, the platelet molar ratio of cholesterol to phospholipid ([C]/[PL]) and platelet microviscosity increased with age ( P < 0.05) and were correlated with one another ( P < 0.05). 3. Age‐dependent increases in the steady state of fluorescence anisotropy, order parameters and the short component of fluorescence lifetime of the fluorophore were expressed as functions of variables, such as microviscosity or the [C]/[PL] ratio. 4. Platelet concentrations of arachidonic and eicosapentaenoic acids increased with age, but were not associated with aggregation. Age‐related changes in microviscosity and the [C]/[PL] ratio seemed to be determinants affecting biophysical properties of platelet aggregation.