Spreading depression and the blood-brain barrier.
The propagation of spreading cortical depression was studied in rabbits during the reversible opening of the blood-brain barrier induced by hypertonic aqueous solutions of sodium chloride and sodium diatrizoate. The rupture of the blood-brain barrier was monitored by the leakage of Evans blue-albumin from pial vessels. Spreading depression was monitored by recording its characteristic slow voltage variations. Test substances were injected into the carotid artery or topically applied to the pia-arachnoid surface. Intracarotid injection of hypertonic solutions that open the blood-brain barrier do not block the propagation of spreading depression. Topical application of NaCl solutions can block the spread of the cortical depression reaction without opening the blood-brain barrier. Recurrent spreading depression waves at a mean frequency of one every 5 min, for 4 h do not cause the release of Evans blue-albumin complex from pial vessels.
D000287:Administration, Topical; D000818:Animals; D001812:Blood-Brain Barrier; D002540:Cerebral Cortex / Q000502:physiology; D013181:Cortical Spreading Depression / Q000187:drug effects*; D003973:Diatrizoate / Q000494:pharmacology*; D005070:Evans Blue / Q000008:administration & dosage; D007269:Injections, Intra-Arterial; D008991:Monitoring, Physiologic; D011817:Rabbits; D012462:Saline Solution, Hypertonic / Q000494:pharmacology*; D012965:Sodium Chloride / Q000494:pharmacology*
D012462:Saline Solution, Hypertonic; D003973:Diatrizoate; D012965:Sodium Chloride; D005070:Evans Blue