Pulmonary intravascular macrophages and hemodynamic effects of liposomes in sheep

• DOI: 10.1152/jappl.1988.64.3.1143
• Publication Date: 2017-12-21T15:07:47Z
• Authors: K. Miyamoto; E. Schultz; T. Heath; M. D. Mitchell; K. H. Albertine; N. C. Staub
• Keywords: Thromboxane B2

We studied the effects of liposomes on pulmonary circulation sheep and found a close correlation between liposome retention in lung intravascular macrophages. A test dose (5.5 mumol total lipids) injected intravenously transiently increased arterial pressure from 24 +/- 2 to 55 16 (SD) cmH2O. The responses were dependent reproducible. rise was blocked completely by indomethacin 75% thromboxane synthase inhibitor. Systemic B2 concentration base-line level less than 50 pg/ml 250 130 at peak pressor response. Larger doses (220 infused over 1 h maximally within first 15 min. Lymph flow lymph protein decreased, suggesting venoconstriction. Over half (62.4 15.7%) 111In-labeled remained after h. Fluorescence transmission electron microscopy showed that greater 90% associated with mononuclear cells lumen alveolar wall microvessels. conclude affect mechanism involving arachidonate cascade, principally thromboxane. Our observations suggest population macrophages is likely be source hemodynamic dynamic changes occur dose-dependent fashion, although interactions liposomes, leukocytes, or endothelial cells, addition macrophages, have not been ruled out. believe this demonstration may metabolites rather neutrophils, perivascular interstitial cells.