The Effect Of Acute Temperature Stress On Blood Components And Key Metabolism Mechanisms In Rainbow Trout(Oncorhynchus Mykiss)

These studies were focused on the subject of Rainbow Trout (Oncorhynchusmykiss), the average weight was240±18g and the average height was25.7±1.7cm,wehave studied the effect of the acute temperature on growth, nutrition, immunity andblood. The fish were cultured in the water with a temperature of6℃（low temperatureanimals）and24℃（high temperature animals）separatelyand maintained for2hours,then put back to16℃water. The content of Blood physiology andbiochemistrycomponents, Serum hormone and the expression of several gene weredetected. The result is as follows:1.Thisstudyfocus on the effects of the acute temperature stress on the number ofRBC and Hb, and the content of several SerumBiochemical Components. The resultsshowed thatthe acute temperature stress has some influences on Blood Cells andSerum Biochemical Components in Rainbow Trout in different degrees. RBC and Hbboth decreased at12h in low temperature animals and at6h in high temperatureanimals after acute temperature stress, and then increased afterwards. WBC had aslightly increase at0h and then restored to control level after stress. GLU decreasedsharply at0h after stress and then maintained low level. TP and ALP had significantdecrease at6h or12h after stress and increased afterwards. TBIL and UREA have nosignificant changes after stress. Ca2+had a significant decrease only at24h and P hada significant increase only at0h, there was no difference at other time in both Ca2+and P. The acute temperature stress has some influences on Blood Cells and SerumBiochemical Components in Rainbow Trout in different degrees, and hightemperature has an more significant influence.2.This studyfocus on the effects ofthe acute temperature stress onCF, HIS, thelevels of Serum AST、ALT、ALPand IGF-1, meanwhile detected the influence of the acute temperature stress on the expression of theGH1R、IGF-1and IGF-2of liver. Theresults showed that CF and HIS have no significant change after the acute temperaturestress. AST and ALT have the same tend that increased firstly and then decreased, andwas significant lower at6h or0h compared to control level. ALP decreased sharply at0h after stress and then maintained low level. Serum IGF-1also decreased sharply at0h after stress and then increased to control level in low temperature animals andmaintained low level in high temperature animals. The expression ofGH1R has aslight but not significant decrease. The expression of IGF-1and IGF-2have the sametend that decreased firstly and then increased, and was significant lower at12hcompared to control level. The results revealed that acute temperature hurt the liverand resulted in the increase of AST and ALT, and the decrease of Serum IGF-1andthe expression of GH1R、IGF-1and IGF-2indicated that acute temperature Affect thegrowth of fish. The changes in high temperature were more significant than in lowtemperature indicated that rainbow trout was more sensitive to high temperature.3.Thisstudyfocus on the effects of the acute temperature stress on the levels ofSerum TC, TG, FT3and FT4, meanwhile detected the influence of the acutetemperature stress on the expression of the TRαand TRβof liver. The results showedthat TC decreased sharply at0h after stress and then increased to control level at24h;TG was lower compared to control level in high temperature, but there was no clearregularity, while in low temperature, TG was significantly lower compared to controllevel and maintained low level in the whole study. FT3was significantly lowercompared to control level at6h and12h, while FT4was significantly lower comparedto control level only at0h. The expression ofTRαand TRβhave the same tend thatincreased firstly and then decreased, and was significant lower at6h or0h comparedto control level. The results indicated that the acute temperaturestress reducedthenormal metabolism of TC and TG, suppressed the function of the thyroid gland, have anadverse effecton the physiological metabolism and the growth of fish.4.Thisstudyfocus on the effects of the acute temperature stress on the numberofWBC, LYM and the level of Serum cortisol, meanwhile detected the influence ofthe acute temperature stress on the expression of theGR1,GR2and MR of liver. The results showed that WBC and LYM both decreased after acute temperature,and LYMwas significantly lower at0h and6h compared to control level. Cortisol increasedsharply at0h after stress and then decreased to control level at24h. The expressionofGR1,GR2and MR also increased after stress. Among which The expressionincreased sharply at0h after stress and then decreased afterwards in in hightemperature animals, while for low temperature animals，the expression have the tendthat increased firstly and then decreased, and was significant higher at6h or12hcompared to control level. The result indicated that rainbow trout attempted torespond to the acute temperature stress, and The body’s immune function wassuppressed,and the growth of body was reduced.