Mesna O J, Wilhelmsen T W, Andersen R A
Department of Zoology, Norwegian University of Science and Technology (NTNU), Trondheim, Norway.
Comp Biochem Physiol B Biochem Mol Biol. 2000 Jan;125(1):21-7. doi: 10.1016/s0305-0491(99)00151-0.
Oxygen uptake was determined in liver and kidney slices from Balb/C and C3H/HeJ mice at various time points related to a 4-day cadmium (Cd) i.p. injection regime, the latter strain being not only the higher metallothionein (MT) responder, but also more Cd sensitive. In both strains Cd injections caused an increase in O2 uptake in the tissues, being more expressed in the higher MT responsive C3H/HeJ strain. An ability for fast, additional increase of O2 uptake in response to subsequent Cd exposure was also induced during the injection regime. Maximal obtainable MT levels in the two strains were estimated by forced overwhelming pneumococcal infection challenge, giving induction values above those obtained for the Cd injections in the Balb/C strain and equal to those obtained for Cd in the more responsive C3H/HeJ strain. Together with direct defendants against harmful oxygen radicals, MT may act complementary as a radical scavenger and by Cd inactivation, but to a higher degree in the C3H/HeJ compared to the Balb/C strain.
在与为期4天的腹腔注射镉(Cd)方案相关的不同时间点,测定了Balb/C和C3H/HeJ小鼠肝脏和肾脏切片的氧摄取量。后一种品系不仅是金属硫蛋白(MT)反应更强的品系,而且对镉更敏感。在两个品系中,注射镉均导致组织中氧摄取量增加,在MT反应更强的C3H/HeJ品系中表现得更为明显。在注射方案期间,还诱导了对后续镉暴露快速额外增加氧摄取的能力。通过强制压倒性肺炎球菌感染挑战估计了两个品系中可获得的最大MT水平,得到的诱导值高于Balb/C品系中注射镉所获得的值,且与反应更强的C3H/HeJ品系中注射镉所获得的值相当。MT除了直接抵御有害氧自由基外,还可能作为自由基清除剂并通过使镉失活发挥互补作用,但与Balb/C品系相比,在C3H/HeJ品系中作用程度更高。