Expression of prostacyclin-stimulating factor, a novel protein, in tissues of Wistar rats and in cultured cells.

We recently purified and cloned a newly identified PGI2-stimulating factor (PSF). In the present study, we examined the PSF expression in the tissues of Wistar rats and in cultured cells, such as fibroblast cells (FCs), endothelial cells (ECs), and smooth muscle cells (SMCs). The expression of PSF was observed in many tissues of Wistar rats, such as brain, lung, liver, kidney, skeletal muscle, and fat tissue. Especially, lung and kidney showed a greater expression than the other tissues. PSF was also expressed in cultured FCs, ECs, and SMCs. These results indicate that PSF is conserved over species, suggesting that PSF plays a significant role in regulating PGI2 production.