Synergism of (15 S)-15-methyl-prostaglandin E1 with either azathioprine or prednisolone on the survival of heart allografts in rats.

Survival time of Brown Norway (BN) to Wistar (WR) heart allografts without immunosuppressive treatment is 7-10 days. Azathioprine or prednisolone do not improve the graft survival in this model significantly. However, treatment with (15 S)-15-methyl-PGE1 (15-M-PGE1), a synthetic long acting prostaglandin, which can be administered orally, in combination with either azathioprine or prednisolone increased the survival of the allogeneic heart grafts substantially. A synergistic inhibitory effect of 15-M-PGE1 and prednisolone was also noted in carrageenan induced granulomatous inflammation.