Jw. Kitlen et al., GROWTH-PERFORMANCE AND RESPIRATORY BURST ACTIVITY IN RAINBOW-TROUT TREATED WITH GROWTH-HORMONE AND VACCINE, Fish & shellfish immunology, 7(5), 1997, pp. 297-304
Size-selected (167+/-11 mm) female rainbow trout were: given a high (1
.8 mu g g(-1) body weight per week) or low (0.35 mu g g(-1)) dose of r
ecombinant bovine growth hormone (GH), delivered by cholesterol pellet
implant; injected with a commercial bivalent (vibriosis-furunculosis)
vaccine; provided with each dose of GH plus vaccine; implanted with a
pellet alone; or left untreated (N=20 per group). Growth in each trea
tment group was monitored over a 7 week period. Four weeks into the tr
ial, and at trial termination, head kidney neutrophils were quantified
using a histochemical method, and their respiratory burst (CL) respon
se evaluated (N=10 per group). By week 4 of the trial, high dose GH tr
eatment was observed to enhance the CL response of vaccinated fish (P<
0.05) above that of control and other groups. High dose GH treated ani
mals also returned greater, although relative to week 4 data significa
ntly lower, CL response at trial termination. Vaccination had an overa
ll negative effect (P<0.05) upon trout growth performance during the t
rial, although this consequence was annulled when vaccine was co-admin
istered with high dose GH. When considered conjointly with the finding
s of others, the results of the present investigation provide evidence
in support of the existence of a hypothalamo-pituitary-immune axis in
teleosts. (C) 1997 Academic Press Limited.