Peroxidase activity as a measure of neutrophil populations in inflammatory peritoneal exudates of rainbow trout, Oncorhynchus mykiss (Walbaum)

Abstract

A quantitative peroxidase assay using tetramethylbenzidine was applied to exudates from peritoneal cavities of rainbow trout which had been inflamed by intraperitoneal injection of Yersinia ruckeri. Most of the peroxidase activity was cell‐associated, with values for extracellular peroxidase below 5% of total peroxidase. No free peroxidase activity was detected in resting cavities. The kinetics of neutrophil numbers and peroxidase activity in peritoneal exudates during the 6 days of inflammation studied followed identical patterns, with a correlation coefficient of 0.996. This shows that the peroxidase assay can be used as an indirect, quantitative evaluation of neutrophil responses during peritoneal inflammation.

Glycogen granules in resting and inflammatory rainbow trout phagocytes-an ultrastructural study

“…No significant differences in glycogen content were found between blood and resting peritoneal neutrophils. This result, in accordance with the observation that peroxidase content in these 2 neutrophil populations was also similar (Afonso et al 1999), may be taken as an indication that the small population of neutrophils found in resting peritoneal cavities of rainbow trout is not activated.…”

Non‐specific immune response associated with infections of lymphocystis disease virus in American plaice, Hippoglossoides platessoides (Fabricius)

“…Phagocytic cells of the fish head kidney include neutrophils and macrophages, the former being the most numerous and the latter the most active (Secombes 1996). Lymphocystis disease was associated with an increase in the efficiency of phagocytosis, presumably because of macrophage activity, and with the production of reactive oxygen species (hydrogen peroxidase) which is associated with both neutrophil activity and fish phagocytosis (Secombes 1996; Afonso, Oliveira, Ellis & Silva 1999). These oxygen free radicals are toxic for bacteria and protozoans (Secombes 1996).…”

Temperature-dependent expression of immune-relevant genes in rainbow trout following Yersinia ruckeri vaccination

“…Even though immersion vaccination with Y. ruckeri bacterin is effective, injection delivery of the bacterin results in a superior protection against ERM compared to other routes of administration (Johnson & Amend 1983). Further, i.p.-injected Y. ruckeri bacterin induces inflammation and influx of neutrophils and macrophages into the peritoneal cavity (Afonso et al 1998(Afonso et al , 1999. Therefore, we focused on the gene expression in immunerelevant organs initiated by i.p.-delivered Y. ruckeri bacterin.…”