Neurotrophins and neurotrophin receptors in human pulmonary arteries

The localization of neurotrophins (NTs) and NT receptors was analyzed in se ctions of human extra- and intrapulmonary arteries by Western blot analysis and immunohistochemistry. In extrapulmonary branches of human pulmonary ar tery, NT and NT receptor immunoreactivity was located in the tunica intima, within endothelium, in the tunica media, within smooth muscle and in the t unica adventitia. In different sized intrapulmonary arteries, NT and NT rec eptor immunoreactivity was observed primarily in the tunica adventitia, A f aint NT and NT receptor immunoreactivity was observed in the tunica media o f large-sized branches of intrapulmonary arteries, but not within medium- o r small-sized intrapulmonary vessels or in tunica intima of different sized intrapulmonary arteries. These findings suggest that NTs may have a role i n the control of vascular responses in the pulmonary system acting as local paracrine or autocrine mediators. The possible relevance of the NT system in human pulmonary vasculature identified in this study is discussed. Copyr ight (C) 2000 S. Karger AG, Basel.