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PC: PS liposomes induce a recruitment of neutrophils and the release of TNFa in the lungs of mice sensitized with Saccharopolyspora rectivirgula
Author(s) -
BELLEMARE F.,
ISRAELASSAYAG E.,
CORMIER Y.
Publication year - 1995
Publication title -
european journal of clinical investigation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.164
H-Index - 107
eISSN - 1365-2362
pISSN - 0014-2972
DOI - 10.1111/j.1365-2362.1995.tb01711.x
Subject(s) - liposome , bronchoalveolar lavage , neutrophilia , dexamethasone , saline , pharmacology , chemistry , tumor necrosis factor alpha , immunology , medicine , lung , biochemistry
. The aim of this study was to verify the effectof nasally instilled liposomes (L) or dexamethasone‐containing L (Ldexa) on normal or inflamed lung tissue. Three groups of mice were studied. Group I was given saline instillations for 3 weeks prior to the instillation with liposomes. In groups I1 and 111 lunginflammation was induced by repeated instillations of Saccharopolyspora rectivirgula before the instillation of liposomes (group 11) or liposomes containing dexamethasone (group 111). Animals from all groups were killed at regular time intervals for up to 48 h after the instillation of liposomes. The total cell count in bronchoalveolar lavage fluid did not differ signifi‐ cantly between groups I and 11. However, in group I11 it decreased rapidly from 6.2 to 2.8 × 10 5 cells mL‐ within 2 h. Differential counts did not change in group I, but in group I1 a transient neutrophilia was observed 180 min after the instillation of liposomes. In group 111, the instillation of dexamethasone‐containing liposomes depleted all neutrophils and lymphocytes after 4h. No TNFa was found in samples of lavage fluid from any of the groups at time 0. In group I, liposomes induced the production of 0.03 ngmL‐l of TNFa in the 1 h sample only. In group 11, TNFa peaked to 1 ngmL ‐1 at 1 h and had decreased to 0.35 ngmL ‐1 by 3 h. In group 111, TNFa peaked at 1 h, but only reached a level of 0.1 ng mL ‐1 . It is concluded that liposomes cause few acute inflammatory effects when instilled in normal lungs, although in the presence of an underlying inflammation these lipids can induce a further neutrophilic response and the release of TNFa. However, this response and the underlying inflammation are inhibited by the incorporation of dexamethasone into the liposomes.