- The major source of endogenous prostaglandin D2 production is likely antigen-presenting cells. Localization of glutathione-requiring prostaglandin D synthetase in histiocytes, dendritic, and Kupffer cells in various rat tissues. Urade, Y., Ujihara, M., Horiguchi, Y., Ikai, K., Hayaishi, O. J. Immunol. (1989)