Effects of intracarotid hyperosmolar mannitol in triethyl tin (TET)-induced rat brain edema--preservation of blood-brain barrier (BBB) in TET edema.

The effect of intracarotid hyperosmolar mannitol on the blood-brain barrier (BBB) in triethyl tin (TET)-induced rat brain edema was examined by using intravenous Evans blue (EB, MW 68,000) and Adriamycin (ADM, MW 580) as tracers. Three ml of 1.4 M mannitol solution were administered through the right carotid artery during 45 s for BBB opening. The barrier was opened for 60-120 minutes and then re-established. The reversibility was preserved in TET-treated rats and controls. In fact, the intravenous injection of EB stained both TET-treated and non-treated cerebral hemispheres with mannitol-induced transient BBB disruption, but not without BBB disruption. BBB was resistant to both high and low molecular weight substances in TET-induced edema. The importance of this hyperosmotic studies provides the evidence for normal BBB function in TET-induced brain edema.