Immunosuppressive effect of human pregnancy zone protein on H-2 incompatible mouse heart allografts.

Human pregnancy zone protein (PZP) given intraveneously, significantly (p less than 0.001) prolonged the survival of heterotopic A/J heart transplants in A.CA recipients, compared to untreated control recipients, recipients treated with phosphate buffered saline and recipients treated with a control preparation from male serum. The results support the hypothesis that PZP protein exerts an unspecific immunosuppressive effect in vivo.