EFFECTS OF DAURICINE AND TETRANDRINE ON ³H WEB 2086 SPECIFIC BINDING TO BOVINE ANTERIOR CEREBRAL ARTERIAL SMOOTH MUSCLE CELLS IN VITRO

By using ³H WEB 2086, a PAF antagonist, specific binding sites of PAF on bovine anterior cerebral arterial smooth muscle cells was identified. Two populations of binding sites with different dissociation constants on the cells were found. The K_d-1=22.8±5.0 nmol.L^-1, K_d-2=186±20.5 nmol.L^-1 at 25 C. The total number of binding sites were B_max-1=2.1±0.3 pmol/10⁶ cells and B_max-2=12.1±1.5 pmol/10⁶cells. Dauricine and tetrandrine, two active compounds with similar chemical structure extracted from traditional Chinese herbs, were found to inhibit ³H WEB 2086 specific binding significantly in culture cells.