Favorable and unfavorable effects of permissive hypercapnia on pulmonary microcirculation - Permissive hypercapnia: Natural or not?

K. Yamaguchi, K. Naoki, K. Nishio, Y. Suzuki, K. Suzuki, T. Aoki, A. Miyata, N. Sato, K. Takeshita, H. Kudo, H. Tsumura

Research output: Contribution to journalArticle

Abstract

To examine the beneficial effects of permissive hypercapnic ventilation (PHC), we studied alterations in pulmonary microvascular reactivity to hypoxia, hydrogen ions or CO2 in injured lungs harvested from animals after prolonged exposure to a hyperoxic environment. In addition, the influence of hypercapnic acidosis induced by PHC on cellular and subcellular functions was examined by analyzing changes in intracellular Ca ions and expression of various adhesion molecules in human pulmonary artery endothelial cells (HPAEC). The following conclusions were obtained in lungs injured by exposure to hyperoxia: 1) constriction of precapillary arterioles in response to hypoxic stimulation is attenuated, probably due to upregulation of COX-1, eNOS, and iNOS within the acini, 2) hydrogen ion-elicited arteriolar constriction is significantly increased, although it appears not to be mediated by either COX- or NOS-related vasoactive substances, 3) in association with intraacinar augmentation in COX, CO2 evoked microvascular dilation is blunted, 4) PHC significantly increases concentration of free Ca ions in HPAECs, 5) depending on the degree of acidosis and on the CO2 concentration, expression of VCAM-1 and ICAM-1 on HPAEC surface is upregulated. These findings suggest that PHC has some disadvantages in addition to the advantages that have been documented.

Original languageEnglish
Pages (from-to)143-147
Number of pages5
JournalJapanese Journal of Thoracic Diseases
Volume35
Issue numberSUPPL.
Publication statusPublished - 1997 Dec 1

Keywords

  • Acinus
  • Adhesion molecules
  • Hyperoxia-exposed lung injury
  • Hypoxic pulmonary vasoconstriction
  • Intracellular free Ca
  • Permissive hypercapnia
  • Pulmonary microcirculation

ASJC Scopus subject areas

  • Pulmonary and Respiratory Medicine

Fingerprint Dive into the research topics of 'Favorable and unfavorable effects of permissive hypercapnia on pulmonary microcirculation - Permissive hypercapnia: Natural or not?'. Together they form a unique fingerprint.

  • Cite this

    Yamaguchi, K., Naoki, K., Nishio, K., Suzuki, Y., Suzuki, K., Aoki, T., Miyata, A., Sato, N., Takeshita, K., Kudo, H., & Tsumura, H. (1997). Favorable and unfavorable effects of permissive hypercapnia on pulmonary microcirculation - Permissive hypercapnia: Natural or not? Japanese Journal of Thoracic Diseases, 35(SUPPL.), 143-147.