title: Automated measurement of blood flow velocity and direction and hemoglobin oxygen saturation in the rat lung using intravital microscopy.
abstract: Intravital microscopy of the pulmonary microcirculation in research animals is of great scientific interest for its utility in identifying regional changes in pulmonary microcirculatory blood flow. Although feasibility studies have been reported, the pulmonary window can be further refined into a practical tool for pharmaceutical research and drug development. We have established a method to visualize and quantify dynamic changes in three key features of lung function: microvascular red blood cell velocity, flow direction, and hemoglobin saturation. These physiological parameters were measured in an acute closed-chest pulmonary window, which allows real-time images to be captured by fluorescence and multispectral absorption microscopy; images were subsequently quantified using computerized analysis. We validated the model by quantifying changes in microcirculatory blood flow and hemoglobin saturation in two ways: 1) after changes in inspired oxygen content and 2) after pharmacological reduction of pulmonary blood flow via treatment with the β1 adrenergic receptor blocker metoprolol. This robust and relatively simple system facilitates pulmonary intravital microscopy in laboratory rats for pharmacological and physiological research.
authors.affiliation: Dept. of Radiation Oncology, Duke University Medical Center, Durham, NC 27710, USA.
authors.forename: Gabi
authors.initials: G
authors.lastname: Hanna
authors.forename: Andrew
authors.initials: A
authors.lastname: Fontanella
authors.forename: Gregory
authors.initials: G
authors.lastname: Palmer
authors.forename: Siqing
authors.initials: S
authors.lastname: Shan
authors.forename: Daniel R
authors.initials: DR
authors.lastname: Radiloff
authors.forename: Yulin
authors.initials: Y
authors.lastname: Zhao
authors.forename: David
authors.initials: D
authors.lastname: Irwin
authors.forename: Karyn
authors.initials: K
authors.lastname: Hamilton
authors.forename: Alina
authors.initials: A
authors.lastname: Boico
authors.forename: Claude A
authors.initials: CA
authors.lastname: Piantadosi
authors.forename: Gert
authors.initials: G
authors.lastname: Blueschke
authors.forename: Mark
authors.initials: M
authors.lastname: Dewhirst
authors.forename: Timothy
authors.initials: T
authors.lastname: McMahon
authors.forename: Thies
authors.initials: T
authors.lastname: Schroeder
mesh_terms: D000818:Animals; D001783:Blood Flow Velocity / Q000187:drug effects; D004912:Erythrocytes / Q000502:physiology; D005260:Female; D006454:Hemoglobins / Q000378:metabolism*; D008168:Lung / Q000098:blood supply; D008790:Metoprolol / Q000494:pharmacology; D008833:Microcirculation / Q000502:physiology*; D018715:Microscopy, Video; D010100:Oxygen / Q000097:blood*; D051381:Rats
chemical_list: D006454:Hemoglobins; D008790:Metoprolol; D010100:Oxygen