The expression of P- and E-selectins in three models of middle cerebral artery occlusion

The expression and localization of P- and E-selectins in rat brain (n = 126) were examined using immunohistochemical techniques at various time points after induction of middle cerebral artery (MCA) occlusion in the suture, thrombotic and embolic models of stroke. Expression of P-or E-selectin was not observed in brain tissue of sham operated control rats (n = 9). P-selectin immunoreactivity was detected as early as 15 min and decreased to control level at 1 h after the onset of the MCA occlusion in all three models. P-selectin then slightly increased at 2 h and peaked at 6 h after MCA occlusion. E-selectin immunoreactivity was first observed at 2 h and peaked at 6 h and 12 h of after MCA occlusion in all three models. P- and E-selectin immunoreactivity was colocalized with von Willebrand factor immunoreactive microvessels. 90.4 +/- 2.0% of all vessels expressing P-selectin immunoreactivity were 7.5 to 30.0 mu m in diameter; 3.6 +/- 1.4% were contained in vessels smaller than 7.5 mu m, and 6.0 +/- 1.8% were localized in vessels greater than 30.0 mu m in diameter. The percent distribution of E-selectin immunoreactive vessels were 75.9 +/- 2.1% in vessels 7.5 to 30.0 mu m in diameter; 23.6 +/- 2.2% were in vessels smaller than 7.5 mu m, and 0.6 +/- 0.4% were localized in vessels greater than 30.0 mu m in diameter. These findings indicate that the temporal profiles of P-and E-selectin expression are independent of these models of MCA occlusion and are consistent with the time course of selectin mediated leukocyte infiltration after focal cerebral ischemia in the rat. (C) 1998 Elsevier Science B.V.