title: Pulmonary carbonic anhydrase in the garter snake, Thamnophis sirtalis.
abstract: This study examined whether the snake lung possesses intravascular carbonic anhydrase (CA). Lungs were perfused with control salines and with salines containing CA inhibitors. Perfusion with control salines resulted in a stable CO(2) excretion, whereas CA inhibitors significantly reduced pulmonary CO(2) excretion. Membrane-permeable and membrane-impermeable CA inhibitors produced comparable decreases in CO(2) excretion, suggesting that extracellular, intravascular CA participated in the pulmonary CO(2)-HCO3(-)-H(+) reactions. Treatment of lungs with phosphatidylinositol specific-phospholipase C (PI-PLC) significantly decreased CO(2) excretion, indicating that CA was connected to the luminal endothelial cell membrane by a phosphatidylinositol glycan linkage. Taken together, these results are the first to demonstrate the presence of membrane-bound, intravascular CA (CA IV) in the snake lung.
authors.affiliation: Department of Biology, Bradley University, 1501 W. Bradley Avenue, Peoria, IL 61625, USA. eks@bradley.edu
authors.forename: Erich K
authors.initials: EK
authors.lastname: Stabenau
authors.forename: Kimberly R N
authors.initials: KR
authors.lastname: Vietti
mesh_terms: D000086:Acetazolamide / Q000494:pharmacology; D000818:Animals; D002245:Carbon Dioxide / Q000378:metabolism / Q000502:physiology*; D002257:Carbonic Anhydrase Inhibitors / Q000494:pharmacology; D002256:Carbonic Anhydrases / Q000302:isolation & purification / Q000502:physiology; D017812:Colubridae / Q000378:metabolism / Q000502:physiology*; D005110:Extracellular Space / Q000201:enzymology / Q000502:physiology; D008168:Lung / Q000201:enzymology*; D010477:Perfusion / Q000379:methods; D011659:Pulmonary Gas Exchange / Q000502:physiology*; D013990:Tidal Volume / Q000502:physiology*
chemical_list: D002257:Carbonic Anhydrase Inhibitors; D002245:Carbon Dioxide; D002256:Carbonic Anhydrases; D000086:Acetazolamide