Adiposity induced by adenovirus 5 inoculation

OBJECTIVE: To investigate the effect of viral inoculation by adenovirus 5 (Ad5) on body composition in a mouse model. DESIGN: Longitudinal monitoring before and after a single injection of virus or saline. SUBJECTS: Two groups of CD1 mice, one group given a single intraperitoneal dose of Ad5 and the control group, saline. MEASUREMENTS: Bodyweights and food intake were recorded before and up to 21 weeks after inoculation. At the end of the study, whole-body H-1 magnetic resonance spectroscopy (MRS) and localised in vivo H-1 MRS spectroscopy of the liver was performed to assess whole-body adiposity and intrahepatic lipid content, respectively. RESULTS: Ad5-treated animals gained significantly more weight over a period of 21 weeks after inoculation than the controls, 21.8 g (18.8 - 25.0) and 18.8 g (17.3 - 19.8) respectively, (P < 0.05). The gain in bodyweight in the former animals arises from increased deposition of adipose tissue as measured by whole-body H-1 MRS. Adiposity was 6.7% (3.10 - 11.20%), and 2.40% (0.85 - 5.65%) for the Ad5-treated and control animals, respectively (P < 0.05). No significant difference in intrahepatic lipid content or food intake was observed between the two groups. CONCLUSION: The significantly higher percentage of adipose tissue in the Ad5- treated mice suggest viral infection may play a contributory role to a predisposition to obesity, although its contribution relative to other factors remains to be determined. International Journal of Obesity (2005).