Investigation of PAR-1-type thrombin receptors in rat glioma C6 cells witha novel monoclonal anti-PAR-1 antibody (Mab COR7-6H9)

Rat glioma C6 cells have been demonstrated to be a suitable model in the in vestigation of PAR-1-type thrombin receptors in brain. However, anti-PAR-1 antibodies, which should be very helpful tools in studying PAR-1 in rat cel ls, have not been available up until now. Therefore, we prepared a monoclon al anti-thrombin receptor antibody (Mab COR7-6H9) directed against the pept ide sequence GRAVYLNKSRFPPMPPPPFISEDASG in the N-terminus below the thrombi n cleavage site of the rat PAR-1-type thrombin receptor. Using this antibod y, we demonstrated the presence of PAR-1 binding sites on the plasma membra ne of rat glioma C6 cells both with confocal laser fluorescence and with sc anning electron microscopy. In addition, Mab COR7-6H9 was shown to block PA R-1-mediated transmembranal signaling as demonstrated by measurement of fre e intracellular calcium and cyclic AMP. This novel anti-PAR-1 antibody is t herefore likely to be a very helpful tool in studying PAR-1-type thrombin r eceptors in rat brain.