Ultraviolet radiation-induced inflammation and leukocytes.

To evaluate the role of leukocytes in inflammation induced by ultraviolet radiation, the response of guinea pigs make leukopenic with cyclophosphamide was compared with the response of nonleukopenic animals. The response of leukopenic animals to UVB (295 nm) was significantly altered. Leukopenic animals and saline-treated (i.e., nonleukopenic) animals responded similarly to (1) UVC (250 nm), (2) UVA (340 nm) given after 8-methoxypsoralen pretreatment (PUVA), (3) intradermal histamine and (4) a topically applied prostaglandin analogue. These results suggest that leukocytes are important in UVB-induced inflammation but not in the inflammation induced by UVC or PUVA.