The effects of long-duration, low-temperature ground transportation on physiological and biochemical indicators of stress in mice.

Transportation can cause stress to laboratory animals and alter physiological characteristics that may confound experimental results. The authors investigated stress-related effects of 3-4 h of transportation by truck in two strains of mice (C57BL/6, which are known to be aggressive, and ICR, which are less aggressive). Transported mice had sufficient space and access to water, though temperature in the truck was lower than what is usually recommended. Transportation affected the following parameters in both strains of mice: (i) serum corticosterone concentrations, (ii) expression of the chaperone proteins Hsp70 and Grp78 in various tissues and (iii) concentrations of serological enzymes that are associated with liver disease. These parameters also differed substantially between the two strains of mice.

Overexpression of human selenoprotein M differentially regulates the concentrations of antioxidants and H2O2, the activity of antioxidant enzymes, and the composition of white blood cells in a transgenic rat.

Selenoprotein is associated with a variety of serious diseases, including infectious diseases, neurodegenerative disorders, cancer and cardiovascular disease. The aim of this study was to produce a new transgenic (Tg) rat expressing human selenoprotein M (SelM) in order to examine the protective function of the antioxidant status in vivo. To achieve this, a new lineage of Tg rats was produced by the microinjection of pCMV/GFP-hSelM constructs into a fertilized rat egg. Several conclusions can be drawn based on the results of the present study. The human SelM gene was successfully expressed at both the transcription and protein levels in the CMV/GFP-hSelM Tg rats. This Tg rat showed a different enzyme activity for the antioxidant protein in the various tissues examined. In response to the 2,2'-azobiz(2-amidinopropane) dihydrochloride (AAPH) injection, the Tg rats showed a lower level of antioxidant and H2O2 concentration as the activity of the antioxidant enzyme was maintained at a higher level in the Tg rats than in the non-Tg rats. Also, the neutrophil-to-lymphocyte ratio was significantly increased in this Tg rat, even though the level of corticosterone remained unchanged in both genotypes. Thus, the results of this study demonstrated that the CMV/GFP-hSelM Tg rat can serve as an animal model for the maintenance of a high level of antioxidant status and can be used to study the biological function of selenoprotein in infectious diseases, cardiovascular disease and cancer.