ABSTRACT
BACKGROUND: The angiotensin system has a role in the pathogenesis of pulmonary fibrosis. This study examines the antifibrotic effect of losartan, an angiotensin II type 1 receptor antagonist, in bleomycin induced lung fibrosis and its possible implication in the regulation of prostaglandin E(2) (PGE(2)) synthesis and cyclooxygenase-2 (COX-2) expression. METHODS: Rats were given a single intratracheal instillation of bleomycin (2.5 U/kg). Losartan (50 mg/kg/day) was administrated orally starting one day before induction of lung fibrosis and continuing to the conclusion of each experiment. RESULTS: Losartan reduced the inflammation induced by bleomycin, as indicated by lower myeloperoxidase activity and protein content in the bronchoalveolar lavage fluid. Collagen deposition induced by bleomycin was inhibited by losartan, as shown by a reduction in the hydroxyproline content and the amelioration of morphological changes. PGE(2) levels were lower in fibrotic lungs than in normal lungs. Losartan significantly increased PGE(2) levels at both 3 and 15 days. A reduction in COX-2 expression by bleomycin was seen at 3 days which was relieved by losartan. CONCLUSIONS: The antifibrotic effect of losartan appears to be mediated by its ability to stimulate the production of PGE(2). Losartan, which is already widely used clinically, could be assessed as a new treatment in lung fibrosis.
Subject(s)
Angiotensin II Type 1 Receptor Blockers/therapeutic use , Dinoprostone/metabolism , Losartan/therapeutic use , Pulmonary Fibrosis/prevention & control , Animals , Antimetabolites, Antineoplastic , Bleomycin , Cyclooxygenase 2/metabolism , Male , Pulmonary Fibrosis/chemically induced , Pulmonary Fibrosis/metabolism , Random Allocation , Rats , Rats, Sprague-Dawley , Reverse Transcriptase Polymerase Chain ReactionABSTRACT
Diffuse pulmonary ossification, a rare condition characterized by metaplastic ossification of the lung, is usually associated with diseases causing diffuse pulmonary lesions. Two types dendriform and nodular have been identified. In dendriform ossification, the less common type, osseous ramifications occur along the distal airways, with occasional islets of bone marrow. We report a case of diffuse dendriform pulmonary ossification associated with idiopathic pulmonary fibrosis. The diagnosis was based on histological examination, which demonstrated multiple nodules and ramified osseous spicules around the lung, mainly at the lower lobes, where the fibrotic lesions were also most evident.
Subject(s)
Lung/pathology , Ossification, Heterotopic/pathology , Pulmonary Fibrosis/pathology , Aged , Biopsy , Humans , Male , Ossification, Heterotopic/diagnostic imaging , Pulmonary Fibrosis/diagnostic imaging , Radiography, Thoracic , Tomography, X-Ray ComputedABSTRACT
La osificación pulmonar difusa es una entidad poco frecuente en la que se produce una metaplasia ósea del pulmón y que suele asociarse con enfermedades que ocasionan lesiones pulmonares difusas. Existen dos tipos de osificación pulmonar: la dendriforme y la nodular. La forma dendriforme es la menos frecuente y se caracteriza por ramificaciones de estructura ósea a lo largo de las vías aéreas distales con islotes ocasionales de médula ósea. Se presenta un caso de osificación pulmonar difusa de tipo dendriforme asociada con fibrosis pulmonar idiopática. El diagnóstico se estableció mediante el examen histológico, que demostró la presencia de múltiples nódulos y espículas óseas ramificadas en la periferia del pulmón, principalmente en los lóbulos pulmonares inferiores, donde las lesiones fibróticas eran más evidentes. (AU)
