No abstract

No abstract

Abstract:The primary aim of the present study was to define central and peripheral physiological differences between dietary obesity-susceptible (DOS) and obesity-resistant (DOR) outbred Sprague Dawley (SD) rats when given a moderate high fat diet containing 32.34% of energy as a fat. After a 9-week feeding period, the DOS-SD rats consumed significantly more feed (11.1%) and had higher abdominal (39.9%) and epididymal (27.5%) fat pads than the DOR-SD rats. In addition, serum leptin and insulin levels were significantly increased in the DOS-SD rats compared with those in the DOR-SD rats. However, we did not observe significant differences in serum triglyceride, cholesterol and glucose. No differences in hypothalamic OB-Ra and Rb mRNA expressions were found between the two groups. In contrast, arcuate NPY immunohistochemical expression was much higher in the DOS-SD rats than in the DOR-SD rats, though NPY expression in the supraoptic and paraventricular nuclei was not different between the two phenotypes. In peripheral tissues, the DOS-SD rats showed noticeably increased acetyl CoA carboxylase (ACC) mRNA expression in the liver, not epididymal fat. However, Western blot of peroxisomal proliferator activated factor γ (PPARγ) in the liver and epididymal fat was not different between the two phenotypes of SD rats. It was concluded that different body weight phenotypes within outbred SD population responded differently to the development of dietary induced obesity via altered anabolic features in the hypothalamus and liver.

No abstract

Laboratory animals generally experience numerous unfamiliar environmental and psychological influences such as noises, temperatures, handling, shaking, and smells during the process of air transportation. To investigate whether stress induced by air transportation affects stress-related factors in animals, the levels of hormone and chaperone protein were measured in several tissues of F344 rats transported for 13 h and not transported. Herein, we conclude that the levels of corticosterone, HSP70, and GRP78 were significantly increased in the transported group compare to not transported group, but they were rapidly restored to the not transported group level after a recovery period of one week. However, the magnitude of induction and restoration levels of these factors varied depending on the tissue type. Thus, these results suggest that air transportation should be considered for the improvement of laboratory animal health and to reduce the incidence of laboratory animal stress.