Overnight food deprivation in normal and diabetic mice markedly enhances thromboxane production by arachidonate stimulated platelet rich plasma and markedly increases platelet phospholipase A₂ activity

These studies report the effect of overnight food deprivation on thromboxane production by mouse platelets stimulated with arachidonic acid. Phospholipase activity was also measured. We used radioimmunoassay to measure thromboxane B₂ (TxB₂) in platelet rich plasma (PRP) stimulated with 0.5 mM sodium arachidonate. TxB₂ levels increased from 30 to 180 seconds after stimulation, and at 90 and 180 seconds were approximately twice as high in PRP from food deprived mice as compared with levels in PRP from fed animals (P<.01). The same period of food deprivation (17-21 hours) doubled the phospholipase A₂ (PLA₂) activity of the mouse platelets. No significant differences were observed between the TxB₂ levels in PRP from normal mice and the PRP from mice with streptozotocin diabetes, although the marked elevation of TxB₂ levels produced by food deprivation was somewhat greater in the PRP from diabetics. No differences were observed in PLA₂ activity in diabetic as compared with control platelets. The marked enhancement of PLA₂ activity produced by food deprivation, was seen in both control and diabetic platelets.