Increased platelet intracellular calcium concentration in patients with bipolar affective disorders

Area of Science:

• Neuroscience
• Biochemistry
• Psychiatry

Background:

• Intracellular calcium ions play a crucial role in platelet activation and signaling.
• Dysregulation of intracellular calcium has been implicated in various mood disorders.
• Platelets offer a accessible model for studying cellular mechanisms in psychiatric conditions.

Purpose of the Study:

• To investigate differences in free intracellular calcium ion concentration in blood platelets across various mood disorder states.
• To compare calcium mobilization responses to specific agonists between patients with mania, bipolar depression, unipolar depression, and healthy controls.

Main Methods:

• Utilized the fluorescent indicator Fura 2 to measure free intracellular calcium ion concentration.
• Assessed baseline calcium levels and responses to platelet-activating factor and thrombin stimulation.
• Included patients with untreated mania, bipolar depression, unipolar depression, recovered patients, and age/sex-matched controls.

Main Results:

• Significantly increased baseline intracellular calcium in platelets of patients with mania compared to controls.
• Significantly higher intracellular calcium after stimulation in platelets of manic and bipolar depressed patients versus other groups.
• A significantly lower increase in intracellular calcium over baseline upon stimulation in unipolar patients compared to bipolar patients.

Conclusions:

• Platelets from manic and bipolar depressed patients demonstrate enhanced intracellular calcium activity.
• Unipolar patients show a distinct impairment in intracellular calcium mobilization in response to stimulation.
• These findings suggest differential platelet calcium handling mechanisms in bipolar versus unipolar depression.