Mechanisms of decrease in cytoplasmic motility of alveolar macrophages during immediate asthmatic response in dogs

M. Yamaya, K. Zayasu, K. Sekizawa, K. Yamauchi, T. Fukushima, H. Sasaki, T. Takishima

Research output: Contribution to journalArticlepeer-review

2 Citations (Scopus)

Abstract

To study the cytoplasmic motility (CM) of alveolar macrophages (AM) during immediate asthmatic response, we measured remanent field strength (RFS) in dogs in vivo after Ascaris suum-antigen (AA) inhalation. Four days after instillation of ferrimagnetic particles (Fe3O4, 3 mg/kg) into the right lower lobe bronchus, RFS was measured at the body surface immediately after magnetization of the Fe3O4 particles by an externally applied magnetic field. RFS decreased with time because of particle rotation (relaxation). Relaxation is thought to be correlated to CM of AM (J. Appl. Physiol. 55: 1196-1202, 1983). AA inhalation increased respiratory resistance (Rrs) in 10 dogs (responders; P < 0.01), and did not change Rrs in five dogs (nonresponders; P > 0.50). The relaxation rate (λ0) significantly decreased because of AA inhalation in responders (P < 0.01), whereas λ0 did not change in nonresponders (P > 0.50). Intravenous injection of indomethacin or diclofenac sodium (5 mg/kg) 30 min before AA inhalation completely inhibited the decrease in λ0 induced by AA inhalation, although both drugs did not inhibit the increase in Rrs (P > 0.10). In in vitro experiments, AM (5 x 106 cells) harvested by bronchoalveolar lavage showed a significant dose-dependent decrease in λ0 with prostaglandins (PG) E1 and E2. However, histamine and platelet-activating factor increased λ0 significantly (P < 0.01), whereas PGD2, PGF(2α), PGI2, thromboxane A2, leukotrienes B4, C4, and D4, and AA itself were without effect (P > 0.50). Furthermore, PGE2 aerosols mimicked AA-induced effects on AM. These results suggest that bronchoconstriction and changes in CM of AM are mediated via different mechanisms, and cyclooxygenase products of arachidonate metabolism, probably the PGE series, are responsible for the decrease in λ0 during immediate asthmatic response.

Original languageEnglish
Pages (from-to)L220-L226
JournalAmerican Journal of Physiology - Lung Cellular and Molecular Physiology
Volume258
Issue number3 2-2
DOIs
Publication statusPublished - 1990

Keywords

  • Ascaris antigen
  • bronchial hyperreactivity
  • cytoskeletal system
  • ferrimagnetic particles
  • remanent field strength

ASJC Scopus subject areas

  • Physiology
  • Pulmonary and Respiratory Medicine
  • Physiology (medical)
  • Cell Biology

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