Peritoneal and head kidney cell response to intraperitoneally injected yeast glucan in Atlantic salmon, Salmo salar L.

Abstract

Previous studies have shown that intrapcritoneal (i.p.) injection of a yeast cell wall glucan into Atlantic slamon, Salmo salar L., resulted in increased resistance to bacterial pathogens and that the glucan enhanced the protective effect of an i.p.-administered furunculosis vaccine in salmon. In the present work, the peritoneal cell responses to yeast glucan, glycogen, Frcund's incomplete adjuvant (FIA) and saline were compared. Whereas saline gave no detectable peritoneal cell response, injection of the three other agents resulted in accumulation of maerophages, neutrophils and thrombocytes in the peritoneal cavity 2-22 days later. Glucan and glycogen gave maximum leucocyte responses 2 days after injection, whereas the number of leucocytes after FIA injection showed a eontinuous increase during the 22-day experimental period. Two days after injection, maerophages dominated in the leucocyte response to yeast glucan, whereas neutrophils dominated in response to glyeogen and FIA. At 8 and 22 days post-injection of yeast glucan and FIA, thrombocytes represented the largest fraction of peritoneal cells. Except for an elevated number of neutrophils 3 weeks after injection, i.p. administration of yeast glucan gave no significant change in leucocyte numbers from the head kidney. On the other hand, head kidney maerophages from glucan-trcated fish showed an increased ability to kill a virulent strain of Aeromonas salmonicida.

The viability of probiotics as a factor influencing the immune response in the Nile tilapia, Oreochromis niloticus

“…S. cerevisiae contains various compounds such as β-glucans, nucleic acids and mannan oligosaccharides which are considered as immunostimulating compounds (Siwicki et al, 1994;Anderson et al, 1995;Ortuño et al, 2002). It has been recognized that nucleic acids and β-1,3-glucans effectively enhanced immune functions of African catfish (Yoshida et al, 1995), Atlantic salmon (Engstad et al,1992), rainbow trout (Jørgensen et al, 1993;and Siwicki et al, 1994) and shrimp Penaeus monodon (Thanardkit et al, 2002).…”

The leucocyte population of the unstimulated peritoneal cavity of rainbow trout (Oncorhynchus mykiss)

“…Very restricted data have been reported for the resting peritoneal leucocyte population of salmonids (Zeliko# & Enane, 1992;Enane et al, 1993;Jørgensen et al, 1993). While the paper by Jørgensen et al (1993) on peritoneal inflammatory responses to phlogistic agents in Atlantic salmon does not include values for the resting cavity, the work by Zeliko# & Enane (1992) and by Enane et al (1993) reports the controversial finding that the resident peritoneal population of rainbow trout would be entirely made up of macrophages. Here, the leucocyte population was analysed in detail in the unstimulated peritoneal cavity of rainbow trout.…”

The stimulatory effect of a muscle protein hydrolysate from Atlantic cod,Gadus morhuaL., on Atlantic salmon,Salmo salarL., head kidney leucocytes

“…The respiratory burst is probably one of the most important bactericidal mechanisms of phagocytes (Johnston, 1978;Secombes & Fletcher, 1992). Increased respiratory burst activity of fish phagocytes has been described in several studies (Graham et al, 1988;Jørgensen et al, 1993a;Sveinbjørnsson & Seljelid, 1994;Dalmo & Seljelid, 1995) and could be correlated with increased killing ability (Jørgensen et al, 1993b;Sharp & Secombes, 1993). Changes in lysosomal enzyme activities have also been used as criteria for activated macrophages (Cohn, 1978).…”