부산대학교 도서관

Using laser scanning confocal microscope (LACM) and flow cytometry (FCM), we found that MK571, a specific inhibitor of multidrug resistance-associated protein (MRP), could increase the accumulation of calcein-AM in Prorocentrum lima, a DSP toxin-producing dinoflagellate. This led to the assumption that the cells of P. lima possess MRP transporters in the plasma membrane. The contents of okadaic acid (OA), a main component of DSP toxins, and MRP activities in P. lima were determined at 4, 20, 28, and 42 days after culture and at 38 day under N- and P-limited conditions. We found that both the OA level and MRP activity in P. lima increased over time; OA concentration and MRP activity conformably increased under N- and P-limited conditions compared with control counterparts. These changes in OA concentration and associated increased MRP activity suggest that MRP might be involved in OA transport in P. lima. However, MK571 and CsA, a broad-spectrum inhibitor of multidrug resistance (MDR)-associated ABC proteins, had no observable effects on OA content in P. lima. It seems that except for MDR-associated ABC proteins, other transporters like PDR might be involved in the transport of OA in P. lima. [ABSTRACT FROM AUTHOR]