Breakdown of the blood-brain barrier and neuropathological changes induced by Phoneutria nigriventer spider venom

摘要: The blood-brain barrier (BBB) is responsible for selective flux of substances between blood and brain. permeability the BBB crucial maintenance brain microenvironment homeostasis, alterations in may be involved many pathophysiological processes. Phoneutria nigriventer armed spider venom produces excitatory signals symptoms humans, its recognized neurotoxic action suggests a potential ability to alter permeability. aim present study was investigate capacity P. (PNV) promoting breakdown adult rats. After intravenous injection 850 µg/kg whole venom, lesions were evaluated after 18 h 9 days by ultrastructural methods using extracellular tracer lanthanum nitrate. Clinical signs rats showed acute neurotoxicity, with some animals presenting convulsions, but which clinically resolved 12 post-envenoming. results that PNV able increase permeability, particularly hippocampus. Changes first detected arterioles post-capillary venules 5 inoculation. increased permeation peaked on day 1, representing about 42% examined vessels (P<0.01). This appeared occur both transendothelial intercellular routes, i.e., pinocytic transport through interendothelial junctions. Concomitantly, surrounding tissue vasogenic edema swollen astrocytic processes, without inflammatory infiltrates. peak occurrence observed 3, 60% (P<0.001). Enhanced capillary 9, affected 36% all capillaries (P<0.05). characterized number pinocytotic vesicles, which, addition, filled tracer, visible pathway. demonstrates systemic inoculation induces trans- paracellular routes. It concluded an event not associated neurotoxicity exhibited