Effects Of Different Levels Of Molybdenum On Rumen Milieu Interne And MRNA Expression Of Apoptosis Related Gene In Tissues From Goats

Objective: This experiment was conducted to investigate the effects of different levelsof molybdenum on rumen milieu interne and mRNA expression of apoptosis related genein tissues from goats. In the hope of it can provide theoretical basis for further study on themechanism of molybdenum poisoning.Methods:Selected36healthy Boer goats as experimental animals,which are dividedinto four groups at random,used (NH4)6Mo7O244H2O as test source of molybdenum.Thelevel of ammonium molybdate added set0,15,30and45kg-1(Mo)BW4gradient,pouredpoison once a day.The cycle of experiment continued50days.On days0,25and50of theformal experiment. Three goats were randomly killed from each groups. Collected rumenfluid for the determinations of pH, total ciliate, ciliate vitality, ammonia nitrogen, parasiteprotein and bacterial protein. Taking a small amount of goat liver, kidney and spleentissues to observe tissue ultrastructure by the transmission electron microscope. Anddeterminate mRNA expression of Bcl-2、Bax、Cyt C、Caspase-3and Smac/DIABLO genesrelated to apoptosis in tissues,by the method of TaqMan fluorescent quantitative PCR.Results:(1)Compared with control group, with the increase of molybdenum levels,total ciliates, ciliate activity and the parasite protein were significantly decreased (P<0.05or P<0.01),and it was positively correlated with irrigation poison time. Ammonia nitrogenand bacterial protein concentration were significantly decreased in15mg kg-1group(P<0.05or P<0.01).However,Ammonia nitrogen and bacterial protein concentrationwere significantly increased in15mg kg-1and45mg kg-1group(P<0.05or P<0.01).(2)Observing with the transmission electron microscopy, cells mainly appeared thatthe expansion of endoplasmic reticulum in varying degrees and the number ofmitochondria decreased significantly in high molybdenum group of goat liver, kidney andspleen tissues.Meanwhile,some mitochondria swelled,inside and outside two cavityexpanded,cristae were vague and even mitochondria cristae appeared damage andcavitation.(3)Compared with control group, with the increase of the molybdenum levels, in25and50days from the date of official test,the mRNA expression of bcl-2was significantlydecreased in goat liver and kidney tissues(P<0.05or P<0.01).The mRNA expression ofbax was significantly increased in goats kidney tissues(P<0.05or P<0.01).The mRNAexpression of Cyt C and Caspase-3were significantly increased in goats liver,kidney andspleen tissues(P<0.05or P<0.01).The mRNA expression of Smac/DIABLO wassignificantly increased in goats liver and kidney tissues(P<0.05or P<0.01).Conclusion:Different levels of molybdenum can interfere with the steady state of rumen environment from goats. The mRNA expression levels of genes related to cellapoptosis appeared significant difference in issues and had an indispensable part of themechanism in mitochondrial apoptosis.