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

K. Nishiwaki, D. P. Nyhan, R. S. Stuart, P. Rock, P. M. Desai, W. P. Peterson, P. A. Murray

Research output: Contribution to journalArticlepeer-review

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 (LPQ̇) 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 LPQ̇ 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 LPQ̇ 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.

Original languageEnglish (US)
Pages (from-to)H917-H925
JournalAmerican Journal of Physiology - Heart and Circulatory Physiology
Volume264
Issue number3 33-3
DOIs
StatePublished - 1993

Keywords

  • U- 46619
  • acetylcholine
  • bradykinin
  • chronic instrumentation
  • endothelium independent vasodilation
  • endothelium-dependent vasodilation
  • guanosine 3',5'-cyclic monophosphate-mediated vasodilation
  • hypertension
  • pressure-flow plots
  • pulmonary circulation
  • sodium nitroprusside

ASJC Scopus subject areas

  • Physiology
  • Cardiology and Cardiovascular Medicine
  • Physiology (medical)

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