The ototoxic mechanisms of
cisplatin on the organ of Corti and spiral ganglion neurons have been extensively studied, while few studies have been focused on the stria vascularis (SV). Herein, we verified the functional and morphological impairment in SV induced by a single injection of
cisplatin (12 mg/kg, I.P.), represented by a reduction in Endocochlear Potentials (EP) and strial
atrophy, and explored underlying mechanisms. Our results revealed increased extravasation of chromatic tracers (
Evans blue dye and
FITC-dextran) around microvessels after
cisplatin exposure. The increased vascular permeability could be attributed to changes of pericytes (PCs) and perivascular-resident macrophage-like melanocytes (PVM/Ms) in number or morphology, as well as the enhanced level of HIF-1α and downstream
VEGF. This capillary leakage led to a high accumulation of
cisplatin in the perivascular space in SV, and disrupted the integrity of blood-labyrinth barrier (BLB). Also, tight junction (ZO-1) loosening and Na+, K+-
ATPase damage was considered to be other critical contributors of BLB breakdown, which resulted in EP drop and consequent
hearing loss. This study explored the role of stria vascularis in
cisplatin-induced
ototoxicity in terms of BLB hyperpermeability and pointed to a novel therapeutic target for the prevention of
cisplatin-related
hearing loss.