Effect of recombinant IL-1 isomers on fetal and adult islet cell function and replication.

Natural human interleukin and the recombinant human IL-1 alpha and beta isomers were tested for effects on both fetal and adult rat isolated pancreatic islets. IL-1 alpha inhibited both replication and insulin secretion and decreased the insulin content of both islets. In contrast, the beta isomer did not affect fetal islets. It is concluded that the two isomers may have different avidities for the same receptors, or that receptors are expressed at different stages of differentiation.