Ultrastructural changes and immunolocalization of P-selectin in platelets from patients with major depression

Abstract Depression is considered an important risk factor in patients with cardiovascular disease (CVD). Although the biological mechanism is unknown, it has been suggested that hyperactivity of platelets may have an important role in the onset and evolution of cardiovascular damage. The goals of this study were to evaluate by transmission electron microscopy and immunohistochemistry the presence of ultra-structural variations in platelets from individuals with recent diagnosis of major depression disease (MDD, patients without previous anti-depressant treatment and from healthy control subjects.). Platelets from depressed patients had a greater proportion of dendritic forms compared with those obtained from control subjects. Morphological changes, such as dilation of open canalicular and dense tubular systems, platelet vacuolization, electrodense pattern of membranes, and a different immunolocalization of P-selectin were observed in the platelets from depressed patients compared with those isolated from healthy subjects. Our results revealed ultra-structural changes in platelets isolated from patients with MDD suggestive of enhanced platelet activation.