A plasmatic factor may cause platelet activation in acute ischemic stroke.

Area of Science:

• Biochemistry
• Hematology
• Neurology

Background:

• Ischemic stroke involves platelet activation.
• Understanding platelet behavior is crucial for stroke pathogenesis.

Purpose of the Study:

• To investigate the role of ionized calcium ([Cai2+]) in platelet activation during ischemic stroke.
• To determine if stroke-related platelet activation stems from a primary platelet defect or an external factor.

Main Methods:

• Measured ionized calcium ([Cai2+]) in gel-filtered platelets using aequorin.
• Compared basal and stimulated [Cai2+] levels in stroke patients and controls.
• Incubated control platelets with plasma from stroke patients.

Main Results:

• Stroke patients exhibited increased basal [Cai2+] 36-72 hours post-stroke.
• Stimulated [Cai2+] increases were higher in stroke patients but showed parallel profiles.
• Exposure to stroke patient plasma raised basal [Cai2+] and induced serotonin release in control platelets.

Conclusions:

• Elevated basal [Cai2+] in stroke patients indicates a reduced platelet activation threshold.
• The findings suggest a plasmatic factor, rather than a primary platelet defect, contributes to this altered platelet activity.
• This research offers insights into the mechanisms of platelet dysfunction in ischemic stroke.