[Production of prostaglandins in mixed lymphocyte cultures (MLC) between allograft donors and recipients]

A prostaglandin-like activity, as evaluated by a bio-assay using the fundus of Rat stomach, has been demonstrated in supernatants of lymphocyte cultures. This activity undergoes a striking increase in supernatants of mixed cultures of allograft donor and recipient cells, when compared with control supernatants of donor or recipient cells cultured alone. This phenomenon is observed after 24 hrs. of culture. It disappears if the supernatant is dialyzed. Little or no increase in prostaglandin-like activity is found in supernatants of primary mixed lymphocyte cultures (without previous allograft), at lest in the first two days of culture.