Stress diminishes infiltration and oxygen metabolism of phagocytic cells in calves

Abstract

The influences of a stress situation on the phagocytic cell function before and after infection with Pasteurella haemolytica were measured in calves. No differences in phagocytic and metabolic activity of alveolar macrophages (AMs) were observed in vitro between cells isolated from stressed and nonstressed animals. The uptake of bacteria and the migration of polymorphonuclear leukocytes (PMNs) did not differ. However, the production of superoxide by PMNs isolated from stressed animals was significantly diminished as compared to control PMNs. The stressed and six of the nine control calves were then infected intrabronchially with P. haemolytica. Phagocytic cell function was again evaluated after three days. The lavage fluid obtained from the lungs of the infected animals contained about three times more PMNs and six times more AMs as compared to the lavage fluid of the control calves. However, the increase in phagocytic cell numbers was less by half in the calves infected after the stress period. No differences were detected in phagocytic and metabolic activity of PMNs and AMs among control, infected, and stressed and infected calves. However, the chemotactic activities of PMNs obtained from infected stressed and infected nonstressed animals were diminished as compared to control PMNs. In conclusion, the metabolic responsiveness of PMNs is diminished and the accumulation of phagocytic cells at a site of infection is reduced after a stress period.

Effect of 1-24ACTH administration on sheep blood granulocyte functions

“…The increase of O 2 -production in controls at T48 can be due to the presence of PMN released from bone marrow as a consequence of repeated samplings: early segmented PMN with different functional activities compared with completely mature ones have been in fact previously reported [6]. The lack of this increase in treated sheep seems to support a previously reported stress-induced depression of O 2 -production [8]. Administration of 1-24ACTH, in contrast, did not influence the oxydative responses of PMN to the different activators.…”

“…Data regarding phagocyte functions in spontaneous or experimentally induced stress, are often contradictory and depend on the type of stressor used and on the step of the phagocytic process studied [1,7,8,12,[17][18][19]21]. However the different steps of the phagocytic process have not yet been simultaneously evaluated.…”

Effect of climatic stress on the immunological reactivity of weaned pigs

“…Therefore, it can be concluded that oxygen-dependent intracellular killing mechanisms were not affected differently by the climatic treatment. The same was found in calves, where stress had no effect on the metabolic and phagocytic responsiveness of alveolar macrophages (22). There was, however, a significant decrease in superoxide generation (22), which was not observed in our experiments with pigs.…”

“…Granulocytes were isolated from peripheral blood samples by lysis of contaminating red blood cells and by differential density centrifugation (22). Superoxide anion generation.…”

Transport Stress Increases Somatic Cell Counts in Milk, and Enhances the Migration Capacity of Peripheral Blood Neutrophils of Dairy Cows

“…Differential counts were determined by counting 100 cells under a microscope. Purified neutrophil suspensions from heparinized-jugular blood were collected by Ficoll-Conray (specific gravity, 1.081) density gradient centrifugation followed by hypotonic lysis of red blood cells and several washes by PBS, as described previously [15]. Based on the May-Grünwald-Giemsa staining and microscopic analysis, cells were routinely determined to be > 95% pure and the viability was determined to be > 98%, as based on Trypan blue exclusion method.…”