Abnormal responses to pulmonary vasodilators in conscious dogs after left lung autotransplantation.

Academic Article

Abstract

  • We investigated the extent to which left lung autotransplantation (LLA) alters endothelium-dependent (bradykinin and acetylcholine) and endothelium-independent (sodium nitroprusside) vasodilation in the pulmonary circulation of conscious dogs. Continuous left pulmonary vascular pressure-flow (LPQ) plots were generated in conscious dogs 3-4 wk post-LLA and in sham-operated controls. LLA resulted in a marked upward shift in the baseline LPQ relationship compared with the control group (P < 0.01), i.e., LLA caused a chronic increase in pulmonary vascular resistance. The thromboxane analogue, U-46619, was used to acutely preconstrict the pulmonary circulation in control dogs, which shifted the control LPQ relationship to the same position measured post-LLA. Under these circumstances, bradykinin, acetylcholine, and nitroprusside caused pulmonary vasodilation in the control group, whereas these responses were either attenuated or reversed to vasoconstriction post-LLA. After acute preconstriction with U-46619 post-LLA, the pulmonary vasodilator responses to bradykinin and acetylcholine were again attenuated, but the response to nitroprusside was unaltered compared with control. These results indicate that a significant component of the chronic increase in pulmonary vascular resistance post-LLA is passively mediated and does not reflect an active increase in baseline vasomotor tone. Moreover, LLA results in an impairment in endothelium-dependent, but not endothelium-independent, pulmonary vasodilation in conscious dogs.
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    Keywords

  • 15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid, Acetylcholine, Animals, Bradykinin, Dogs, Endothelium, Vascular, Lung, Lung Transplantation, Male, Nitroprusside, Prostaglandin Endoperoxides, Synthetic, Vascular Resistance, Vasoconstrictor Agents, Vasodilation, Vasodilator Agents
  • Digital Object Identifier (doi)

    Author List

  • Nishiwaki K; Nyhan DP; Stuart RS; Rock P; Desai PM; Peterson WP; Murray PA
  • Start Page

  • H917
  • End Page

  • H925
  • Volume

  • 264
  • Issue

  • 3 Pt 2