Effect of environmental stress on biochemical and physiological features in cultured fish

Transcription

1 Effect of environmentl stress on biochemicl nd physiologicl fetures in cultured fish Toshiki Nkno, Toshiysu Ymguchi, nd Yoshihiro Ochii Grd. Sch. Agric. Sci., Tohoku Univ., Sendi, Jpn Fmous Smuri Mr. Msmune Dte He is first feudl lord of Sendi re.

2 Reserch Interest Fish re often exposed to complex of stresses derived from both globl nd locl stressors (in both nture nd rtificil conditions). In ddition, the temperture of ocen hs been grdully incresing by globl wrming. We should study on the stress response nd on reltionship between stress nd helth in fish. - Tody s topics - 1. Definition of stress 2. Stress responses in fish 3. Eustress nd distress Our former Ammiy cmpus (Fc. Agric., Tohoku Univ.)

3 Wht is stress? Hirose River, Sendi, Jpn

4 Definition of stress Like rubber bll Stressor: pressure cused by finger (externl fctor) Hnd model: our mster course student Rik Okd Stress stte: sitution of bttered (depressed) rubber bll Externl nd internl stimuli which cuse mny kinds of biochemicl nd physiologicl responses in body

5 Mny types of stress (stressors) Fish re surrounded by mny kinds of stress Physicl stress Temperture Slinity Rdition, etc. Artificil condition Hndling Density, etc. Chemicl (Contminnts) stressphysiologicl stress Chemicls Hevy metl, etc. Infection Nutrition, etc.

6 Differences in therml stress responses of two fish species, temperte coho slmon O. kisutch nd tropicl rbbitfish S. gutttus Sesoko Mrine Sttion, Univ. Ryukyus, Okinw, Jpn Rbbitfish, S. gutttus

7 Therml stress ffected plsm glutthione level Optimum temp.+11 for 2 h Rbbitfish Coho slmon Glutthione (µmol / ml) 0,02, b, b b b, c c 0 control 2h 17h 48h (n=5) Time post stress Min Points: (n=5) 1. In rbbitfish, glutthione (GSH) decresed grdully nd reched its lowest vlue t 48 h post stress. 2. On the other hnd, GSH in coho slmon decresed tenttively t 2 h post stress fter which it then incresed.

8 Therml stress induced lipid peroxides in plsm TBARS (Reltive units) Min Points: Rbbitfish control Time post stress (h) (n=5) TBARS (Reltive units),b Coho slmon Although the plsm lipid peroxides (LPO) levels in rbbitfish were lmost the sme for ll smpling periods, they incresed significntly in coho slmon t both 17 h nd 48 h post stress control Time post stress (h) (n=6) b b

9 Therml stress induced HSP70 expression in the liver Rbbitfish Coho slmon Hsp70/β-ctin b Hsp70/β-ctin b 0 Min Points: control (n=8) Time post stress (h) 0 control (n=4) Time post stress (h) Hsp70 expression in the liver of both fish species incresed t bout 17 h post stress

10 Growth in vertebrte GH/IGF-I Axis Growth is regulted by the growth hormone (GH) nd insulin like growth fctor (IGF) xis. Growth is influenced by complex set of cellulr, endocrine, Pituitry nd environmentl fctors. GH Growth hormone GHR GH receptor IGFreceptor IGFR IGF trnscriptionl fctor IGF Binding protein (IGFBP) Liver Blood vessel IGF Insulin like growth fctor GHR Prolifertion Differentition Metbolism etc. Trget tissue (Muscle, Bone nd Hert etc.) Growth Hiri(1996) Moriym et l. (2000)

11 Therml stress induced GH mrna expression in the pituitry Optimum temp.+11 for 2 h Rbbitfish Coho slmon Min Points: Pituitry GH mrna expression in coho slmon incresed t 2 h post stress but returned to control levels t 17 h nd 48 h post stress. GH mrna expression in rbbitfish pituitry grdully incresed following het stress tretment.

12 Therml stress induced IGF-I mrna expression in the liver Rbbitfish Coho slmon Min Points: Heptic IGF-I mrna in coho slmon grdully decresed following het stress tretment; while in rbbitfish liver it incresed, reching its highest vlue t 17 h post stress before decresing.

13 Rbbitfish Summry Coho slmon The level of stress-relted mrkers in coho slmon hve been chnged by stress t initil stge, compred with rbbitfish. The susceptibility for stress might depend on fish species. Temperte fish species such s coho slmon is subject to therml stress, compred with tropicl fish.

14 Effect of ntibiotics oxytetrcyclineinduced chemicl stress on biochemicl indices in coho slmon Sendi Tnbt Festivl (the Str Festivl, Aug. 2017)

15 High doses of oxytetrcycline induced dmge in the liver of coho slmon OTC OTC: 100 mg/kg body weight/dy for 2 wks Min Points: The both level of heptosomtic index nd plsm ALT/GPT ctivity in OTC-fed fish ws higher thn those in control fish. The liver of OTC-fed fish might be dmged by OTC.

16 High doses of oxytetrcycline decresed totl ntioxidtive ctivity in coho slmon Liver Muscle b Min Points: The totl ntioxidtive ctivities indicted s n oxygen rdicl bsorbing cpcity (ORAC) vlue of both liver nd muscle in OTCfed fish were lower thn those in control fish.

17 Proposed internl phenomen in stressed fish Oxidtive stress might be often induced. Oxidtive stress

18 Influence of stressors on physiology Eustress (good stress) nd Distress (bd stress) Stressor Deficiency Optimum Excess Stte of biologicl system is kind of bll Eustress Bsl Distress Okegbe et l. (2012)

19 The norml functionl stte of biologicl system could be likened to bll on plteu. Stressors cn push the bll to the edge of the precipice, but biologicl systems ctivity mintin the functionl stte. This sometimes requires the orgnism to trnsition to new, qulittively different functionl stte, s cn occur when the stressor is source of eustress.

20 Proposed internl Conclusion phenomen in stressed fish Oxidtive stress is often induced in tissues of fish. So ntioxidtive dietry supplements could suppress oxidtive stress nd improve redox stte nd growth in cultured fish. Stress Mnipultion of eustress (good, positive, moderte stimuli, such s mild physiologicl or therml tretment, osmotic stress, nd light condition) might be useful to control fish fitness in terms of helth, growth, immune system, etc. Oxidtive stress

21 Importnce of eustress study in griculture (quculture s well) Stress Unfortuntely, very few nlysis of stress ttend to the concept of eustress. Eustress Thnk you for your ttention THE END