Effects of pentoxifylline and protein kinase C inhibitor on phorbol ester-induced intercellular adhesion molecule-1 expression in brain microvascularendothelial cells

AIM: To study the potential roles of protein kinase C (PKC) on expression o f intercellular adhesion molecule-1 (ICAM-1) in rat brain microvascular end othelial cells (RBMEC). METHODS: ICAM-1 expression in RBMEC was measured by ELISA analyses. RESULTS: Phorbol ester ( PMA) enhanced the expression of I CAM-1 in a concentration (10 - 100 nmol.L-1) and time (4 - 16 h)-dependent manner in RBMEC. Pentoxifylline (PTX) 1 - 100 mu mol.L-1 and the PKC inhibi tor H7 5 - 50 mu mol.L-1 prevented PMA-induced stimulation of ICAM-1 expres sion. At PTX100 mu mol.L-1 and H7 50 mu mol. L-1, they reached maximal inhi bitory effects [ICAM-1 expression(A) from (0.410 +/- 0.014) to (0.175 +/- 0 .022) and (0.182 +/- 0.013), respectively; P < 0.01]. CONCLUSION: Activatio n of PKC in RBMEC is associated with increased expression of ICAM-1 in RBME C. PTX and H7 preincubation may inhibit PKC-induced up-regulation of ICAM-1 .