Time course of hypoxic pulmonary vasoconstriction in dogs
Ishibe, Y.; Suekane, K.; Umeda, T.; Nakamura, M.; Izumi, T.; Mino, Y.
Masui. Japanese Journal of Anesthesiology 36(1): 53-58
1987
ISSN/ISBN: 0021-4892 PMID: 3560427 Document Number: 288148
The time course of hypoxic pulmonary vasoconstriction was examined in the separately ventilated left lower lobe lung model in 17 anesthetized and open chest dogs. Left lower lobe blood flow .ovrhdot.QLLL and total lung blood flow (.ovrhdot.QT) arterial, right atrial, pulmonary arterial and left atrial blood pressures were measured continuously. A hypoxic response was determined as the changes of .ovrhdot.QLLL, PaO2 and left lower lobe pulmonary vascular resistance when the left lower lobe was ventilated with a hypoxic mixture containing 5% CO2 and balance N2 for 120 min. Immediately after a hypoxic ventilation, .ovrhdot.QLLL decreased and showed the first maximum constriction response returned to the peak of relaxation at 28 min, 57 sec, (mean) and again .ovrhdot.QLLL, but the hypoxic response was sustained for 120 min, of a hypoxic challenge and the 61.9% of blood flow was diverted from the left lower lobe during hypoxia. In conclusion, an initial periodic change of a hypoxic response should be emphasized whenever the results of HPV experiments are examined.