Histological evidence of endothelin-1 in macrophages from sarcoid patients. Immunocytochemical detection of endothelin-1 in bronchoalveolar lavage (BAL) cells from patients with sarcoidosis and control individuals, using rabbit monoclonal antibody to human endothelin-1. Cytoplasm of BAL cells from sarcoidosis was strongly stained relative to controls. Immunostaining also demonstrated that most of the immunopositive cells were macrophages. Reproduced with permission from Terashita et al. Respirology 2006. © Blackwell Publishing .