Abstract
By in situ hybridization with biotinylated human interleukin 1α(IL-1α) cDNA probe, distribution of feline IL-1α mRNA-expressing cells was examined in the tissues from 49 cases diagnosed as feline infectious peritonitis (FIP) by pathological examination. IL-1α mRNA-expressing cells were found in visceral peritoneum, lymphoid organs, liver, kidney, pancreas, digestive tract, lung, pleura, brain, palpebral conjunctiva, and bone marrow. Hybridization signals for IL-1α mRNA were mostly located in the local inflammatory lesions on the serosal surface of various organs and omentum, which were frequently involved in the lesions of FIP (27.8±5.1 cells/mm2). Morphological examination suggested that they were infiltrated macrophages. However, few IL-1α mRNA-expressing macrophages were in the lesions of other organs. These data suggested that IL-1α produced from macrophages in the local inflammatory sites might participate in the initiation and development of the lesions on the visceral peritoneum in FIP.
