PMID- 16808843 OWN - NLM STAT- MEDLINE DCOM- 20060929 LR - 20191210 IS - 1465-993X (Electronic) IS - 1465-9921 (Print) IS - 1465-9921 (Linking) VI - 7 IP - 1 DP - 2006 Jun 29 TI - Hypoxic vasoconstriction of partial muscular intra-acinar pulmonary arteries in murine precision cut lung slices. PG - 93 AB - BACKGROUND: Acute alveolar hypoxia causes pulmonary vasoconstriction (HPV) which serves to match lung perfusion to ventilation. The underlying mechanisms are not fully resolved yet. The major vascular segment contributing to HPV, the intra-acinar artery, is mostly located in that part of the lung that cannot be selectively reached by the presently available techniques, e.g. hemodynamic studies of isolated perfused lungs, recordings from dissected proximal arterial segments or analysis of subpleural vessels. The aim of the present study was to establish a model which allows the investigation of HPV and its underlying mechanisms in small intra-acinar arteries. METHODS: Intra-acinar arteries of the mouse lung were studied in 200 mum thick precision-cut lung slices (PCLS). The organisation of the muscle coat of these vessels was characterized by alpha-smooth muscle actin immunohistochemistry. Basic features of intra-acinar HPV were characterized, and then the impact of reactive oxygen species (ROS) scavengers, inhibitors of the respiratory chain and Krebs cycle metabolites was analysed. RESULTS: Intra-acinar arteries are equipped with a discontinuous spiral of alpha-smooth muscle actin-immunoreactive cells. They exhibit a monophasic HPV (medium gassed with 1% O2) that started to fade after 40 min and was lost after 80 min. This HPV, but not vasoconstriction induced by the thromboxane analogue U46619, was effectively blocked by nitro blue tetrazolium and diphenyleniodonium, indicating the involvement of ROS and flavoproteins. Inhibition of mitochondrial complexes II (3-nitropropionic acid, thenoyltrifluoroacetone) and III (antimycin A) specifically interfered with HPV, whereas blockade of complex IV (sodium azide) unspecifically inhibited both HPV and U46619-induced constriction. Succinate blocked HPV whereas fumarate had minor effects on vasoconstriction. CONCLUSION: This study establishes the first model for investigation of basic characteristics of HPV directly in intra-acinar murine pulmonary vessels. The data are consistent with a critical involvement of ROS, flavoproteins, and of mitochondrial complexes II and III in intra-acinar HPV. In view of the lack of specificity of any of the classical inhibitors used in such types of experiments, validation awaits the use of appropriate knockout strains and siRNA interference, for which the present model represents a well-suited approach. FAU - Paddenberg, Renate AU - Paddenberg R AD - University of Giessen Lung Center, Institute for Anatomy and Cell Biology, Justus-Liebig-University, Giessen, Germany. Renate.Paddenberg@anatomie.med.uni-giessen.de FAU - Konig, Peter AU - Konig P FAU - Faulhammer, Petra AU - Faulhammer P FAU - Goldenberg, Anna AU - Goldenberg A FAU - Pfeil, Uwe AU - Pfeil U FAU - Kummer, Wolfgang AU - Kummer W LA - eng PT - Journal Article PT - Research Support, Non-U.S. Gov't DEP - 20060629 PL - England TA - Respir Res JT - Respiratory research JID - 101090633 RN - 0 (Enzyme Inhibitors) RN - 0 (Free Radical Scavengers) RN - 0 (Nitric Oxide Donors) RN - 0 (Nitro Compounds) RN - 0 (Propionates) RN - 0 (Vasoconstrictor Agents) RN - 0 (Vasodilator Agents) RN - 298-83-9 (Nitroblue Tetrazolium) RN - 642-15-9 (Antimycin A) RN - 76898-47-0 (15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid) RN - EC 1.3.5.1 (Electron Transport Complex II) RN - EC 7.1.1.8 (Electron Transport Complex III) RN - QY4L0FOX0D (3-nitropropionic acid) SB - IM MH - 15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid MH - Animals MH - Antimycin A/pharmacology MH - Cell Hypoxia MH - Electron Transport Complex II/antagonists & inhibitors/metabolism MH - Electron Transport Complex III/antagonists & inhibitors/metabolism MH - Enzyme Inhibitors/pharmacology MH - Free Radical Scavengers/pharmacology MH - In Vitro Techniques MH - Lung/*blood supply MH - Mice MH - Models, Animal MH - Muscle, Smooth, Vascular/metabolism/*physiopathology MH - Nitric Oxide Donors/pharmacology MH - Nitro Compounds/pharmacology MH - Nitroblue Tetrazolium/pharmacology MH - Propionates/pharmacology MH - Pulmonary Artery/metabolism/*physiopathology MH - *Vasoconstriction/drug effects MH - Vasoconstrictor Agents MH - Vasodilation MH - Vasodilator Agents/pharmacology PMC - PMC1524949 EDAT- 2006/07/01 09:00 MHDA- 2006/09/30 09:00 PMCR- 2006/06/29 CRDT- 2006/07/01 09:00 PHST- 2006/04/21 00:00 [received] PHST- 2006/06/29 00:00 [accepted] PHST- 2006/07/01 09:00 [pubmed] PHST- 2006/09/30 09:00 [medline] PHST- 2006/07/01 09:00 [entrez] PHST- 2006/06/29 00:00 [pmc-release] AID - 1465-9921-7-93 [pii] AID - 10.1186/1465-9921-7-93 [doi] PST - epublish SO - Respir Res. 2006 Jun 29;7(1):93. doi: 10.1186/1465-9921-7-93.