Neutrophil turnover in normal rabbit lungs.

Abstract

A B S T R A C T Neutrophil turnover was studied in the blood and alveoli of normal rabbits. Blood neutrophil turnover was examined by two different methods. In the first method, donor rabbit neutrophils were labeled in vivo by injecting tritium-labeled thymidine intravenously. After 72 h recipient rabbits received blood from the donors. The decline of the specific radioactivity of blood neutrophils was used to determine that their half-life was 4.03 h. In the second method, rabbit peritoneal exudative neutrophils were elicited with oyster glycogen. These cells were labeled with "'Indium oxine and infused into the blood of recipient animals. By their decline in specific radioactivity, the half-life of the blood neutrophil was 4.08 h. These halflives are not significantly different.Lung lavage was performed on the animals that received the "'Indium-labeled neutrophils and the turnover time of the lung neutrophil was found to be 2.63 h. The turnover of the alveolar neutrophil pool accounted for only 0.19% of the total turnover of the blood neutrophils. Therefore, the lung appears to contribute only minimally to the total capacity of the body to dispose of neutrophils.

Variations in Neutrophil Count in Preterm Infants With Respiratory Distress Syndrome Who Subsequently Developed Chronic Lung Disease

“…1,2 Thommasen et al 3 reported that during ARDS an acute fall of neutrophils was associated with the onset of respiratory failures, and furthermore, that a progressive decrease in the neutrophil count in the high-risk adult has predic-tive value in the development of ARDS. These findings are strengthened by observations 4 that demonstrated a state of constant interchange between the vascular pool of circulating neutrophils with that of neutrophils in the lungs. It is becoming increasingly evident that ARDS and neonatal RDS (NRDS) are but two variants of lung injury.…”

Fibrin is a determinant of neutrophil sequestration in the lung.

“…2728 However, we observed similar pulmonary hemodynamics in the two groups and reduced pulmonary blood flow did not alter neutrophil kinetics in the sheep lung. 22 Another mechanism of uptake of neutrophils and fibrin may be the stationary intravascular mononuclear phagocytes. 29 We have shown that uptake of particles (99m-Tc-sulfur colloid) by pulmonary intravascular macrophages in sheep is sustained up to 24 hours 30 in contrast to the present observations.…”

Pathogenesis of foreign body infection. Evidence for a local granulocyte defect.

“…In order to get an estimate of the time of exposure of PMN to the tissue cage surface, we studied their turnover time as previously described by Cohen et al (33). Briefly, 5 X 106-1 X 10' Percoll-purified homologous blood PMN were resuspended in 1 ml of PBS.…”

“…The cell-associated radioactivity was usually 70-80% of the added value during the first 30 h after PMN administration into the cages. Turnover rate (k) and turnover time (t,) were calculated as described by Cohen et al (33). Superoxide production.…”