Studies of aggregation and thromboxane B2 synthesis in avian thrombocytes: comparison between...

Comparison of thrombocyte aggregation in response to arachidonic acid and synthesis of prostaglandins from C14-arachidonic acid by thrombocytes was made between atherosclerosis-susceptible White Carneau and atherosclerosis-resistant Show Racer Pigeons. Contrary to the expectations, thrombocytes from atherosclerosis-susceptible pigeons were a) less sensitive to arachidonic acid induced aggregation and b) synthesized less thromboxane B2 (stable product of proaggregatory thromboxane A2) from C14-arachidonic acid. Analysis of fatty acid composition of thrombocyte phospholipids indicated a higher concentration of arachidonic acid in White Carneau Pigeons. These results suggest that thrombocytes from atherosclerosis-susceptible pigeons are altered early and as a defense mechanism display less responsiveness towards aggregation.