title: Vascular Dysfunction in Pneumocystis-Associated Pulmonary Hypertension Is Related to Endothelin Response and Adrenomedullin Concentration.
abstract: Pulmonary hypertension subsequent to an infectious disease can be due to vascular structural remodeling or to functional alterations within various vascular cell types. In our previous mouse model of Pneumocystis-associated pulmonary hypertension, we found that vascular remodeling was not responsible for observed increases in right ventricular pressures. Here, we report that the vascular dysfunction we observed could be explained by an enhanced response to endothelin-1 (20% greater reduction in lumen diameter, P ≤ 0.05), corresponding to an up-regulation of similar magnitude (P ≤ 0.05) of the endothelin A receptor in the lung tissue. This effect was potentially augmented by a decrease in production of the pulmonary vasodilator adrenomedullin of almost 70% (P ≤ 0.05). These changes did not occur in interferon-γ knockout mice similarly treated, which do not develop pulmonary hypertension under these circumstances. Surprisingly, we did not observe any relevant changes in the vascular endothelial nitric oxide synthase vasodilatory response, which is a common potential site of inflammatory alterations to pulmonary vascular function. Our results indicate the diverse mechanisms by which inflammatory responses to prior infections can cause functionally relevant changes in vascular responses in the lung, promoting the development of pulmonary hypertension.
authors.affiliation: Department of Microbiology and Immunology, Montana State University, Bozeman, Montana.
authors.forename: Dan W
authors.initials: DW
authors.lastname: Siemsen
authors.affiliation: Department of Microbiology and Immunology, Montana State University, Bozeman, Montana.
authors.forename: Erin
authors.initials: E
authors.lastname: Dobrinen
authors.affiliation: Department of Microbiology and Immunology, Montana State University, Bozeman, Montana.
authors.forename: Soo
authors.initials: S
authors.lastname: Han
authors.affiliation: Department of Microbiology and Immunology, Montana State University, Bozeman, Montana.
authors.forename: Kari
authors.initials: K
authors.lastname: Chiocchi
authors.affiliation: Department of Microbiology and Immunology, Montana State University, Bozeman, Montana.
authors.forename: Nicole
authors.initials: N
authors.lastname: Meissner
authors.affiliation: Department of Microbiology and Immunology, Montana State University, Bozeman, Montana. Electronic address: steve.swain@montana.edu.
authors.forename: Steve D
authors.initials: SD
authors.lastname: Swain
mesh_terms: D053607:Adrenomedullin / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D016232:Endothelins / Q000378:metabolism*; D006976:Hypertension, Pulmonary / Q000378:metabolism* / Q000503:physiopathology; D007371:Interferon-gamma / Q000378:metabolism; D008168:Lung / Q000378:metabolism*; D008807:Mice, Inbred BALB C; D052250:Nitric Oxide Synthase Type III / Q000378:metabolism; D011010:Pneumocystis / Q000378:metabolism*; D011651:Pulmonary Artery / Q000378:metabolism* / Q000503:physiopathology; D015854:Up-Regulation; D014665:Vasodilator Agents / Q000494:pharmacology
chemical_list: D016232:Endothelins; D014665:Vasodilator Agents; D053607:Adrenomedullin; D007371:Interferon-gamma; D052250:Nitric Oxide Synthase Type III