J. Bogwald et al., THE STIMULATORY EFFECT OF A MUSCLE PROTEIN HYDROLYSATE FROM ATLANTIC COD, GADUS-MORHUA L, ON ATLANTIC SALMON, SALMO-SALAR L, HEAD KIDNEY LEUKOCYTES, Fish & shellfish immunology, 6(1), 1996, pp. 3-16
This study shows the stimulatory capacity of a cod muscle protein hydr
olysate on Atlantic salmon head kidney leucocytes both in, vivo and in
vitro. Increased respiratory burst activities were demonstrated in le
ucocytes after stimulation with a peptide fraction in the molecular we
ight range 500-3000 Da. The respiratory burst activity was quantified
using reduction of nitroblue tetrazolium (NET) as a measure of superox
ide anion production following stimulation with phorbol myristate acet
ate (PMA) as the trigger. In vitro dose-response studies demonstrated
an increased stimulation with increasing concentrations of the peptide
fraction (30-1000 mu g ml(-1)). Intraperitoneal injection of the pept
ide fraction in Atlantic salmon (100 mg kg(-1)) resulted in enhanced l
evels of superoxide anion production in head kidney leucocytes 2 and 4
days post-injection when assayed immediately after isolation. Culturi
ng the cells for 18 or 41 h abolished the stimulatory capacity of the
peptides. Also, increased levels of the lysosomal enzyme acid phosphat
ase were measured in the isolated head kidney leucocytes after intrape
ritoneal injection. Microscopic examination of tissue slices two days
after i.p, administration revealed accumulation of FITC-labelled muscl
e hydrolysate (500-3000 Da) mainly in macrophages and endothelial cell
s of the kidney. (C) 1996 Academic Press Limited