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Medical AI Inquiry: You was designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.  Labels: BACKGROUND, METHODS, RESULTS. Meshes: Angiotensin II Type 1 Receptor Blockers, Angiotensin II Type 2 Receptor Blockers, Animals, Bleomycin, Blood Cell Count, Bronchoalveolar Lavage Fluid, Disease Models, Animal, Hydroxyproline, Imidazoles, Macrophage Inflammatory Proteins, Male, Mice, Mice, Inbred ICR, Pulmonary Fibrosis, Pyridines, Receptor, Angiotensin, Type 1, Receptor, Angiotensin, Type 2, Tetrazoles, Tumor Necrosis Factor-alpha, Vasoconstrictor Agents.
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Does angiotensin II type 2 receptor antagonist reduce bleomycin-induced pulmonary fibrosis in mice? Context: The role of angiotensin II type 2 receptor (AT2) in pulmonary fibrosis is unknown. To evaluate the influence of angiotensin II type 1 receptor (AT1) and AT2 antagonists in a mouse model of bleomycin (BLM)-induced pulmonary fibrosis. We examined effects of the AT1 antagonist (AT1A) olmesartan medoxomil (olmesartan) and the AT2 antagonist (AT2A) PD-123319 on BLM-induced pulmonary fibrosis, which was evaluated by Ashcroft's pathological scoring and hydroxyproline content of lungs. We also analyzed the cellular composition and cytokine levels in bronchoalveolar lavage fluid (BALF). With olmesartan, the lung fibrosis score and hydroxyproline level were significantly reduced, and lymphocyte and neutrophil counts and tumor necrosis factor (TNF)-alpha levels in BALF were reduced on day 7. On day 14, macrophage and lymphocyte counts in BALF were reduced, accompanied by a reduction in the level of transforming growth factor (TGF)-beta1. With PD-123319, the lung fibrosis score and hydroxyproline level were reduced. On day 7, macrophage, lymphocyte, and neutrophil counts in BALF were reduced, accompanied by reductions in TNF-alpha and monocyte chemoattractant protein (MCP)-1 levels. On day 14, macrophage, lymphocyte, and neutrophil counts in BALF were also reduced, accompanied by a reduction in the level of macrophage inflammatory protein (MIP)-2 level but not TGF-beta1.
assistant
Both AT1 and AT2 are involved in promoting interstitial pneumonia and pulmonary fibrosis via different mechanisms of action. Final Decision: yes