The synergistic effect of sustained administration of neuropeptide y and norepinephrine on the brown fat metabolic activity in cold acclimated obese rats - biomed 2009.

In previous study, we have reported the effects of chronic peripheral infusion of Neuropeptide Y (NPY) and norepinephrine (NE) alone and together on the metabolic activity of the brown adipose tissue (BAT) in warm acclimated studies in genetically obese reflected in the changes in the size of the triglyceride droplets (TGD) of this tissue. Do these hormones have the same effects on cold-acclimated genetically obese animals? Twenty obese (fa/fa) Zucker strain rats were studied. Again, we can confirm that in these animals NE enhanced the metabolic activity of BAT; NPY had an enhancing effect but with lower level than NE. The combined treatment of rats with both hormones resulted in the highest level of metabolic activity of these animals. We suggest that these animals have higher response to these treatments when they are acclimated to cold environment.