Photochemical (PUVA) treatment of isolated rat islets.

Isolated rat islets were irradiated with long-wave ultraviolet light alone or in combination with the photosensitizer 8-methoxypsoralen. The influences on specific beta cell functions were determined with the aim of finding out experimental conditions which allow the use of such islets for transplantation. Short-term effects: Ultraviolet light affected [3H]leucine incorporation into (pro)insulin (5 J/cm2: 53.8%, 10 J/cm2: 41.0% of the controls) and insulin release was slightly reduced. 8-methoxypsoralen enhanced the irradiation effect. Long-term effects: A restoration of irradiation-affected beta cell function was detected after 5 days of culture unless the dose exceeded 2 J/cm2 (0.1 microM 8-methoxypsoralen) or 1 J/cm2 (1 microM 8-methoxypsoralen). After functional restoration islets can be used for transplantation experiments.