Acetyl-CoA carboxylase and fatty acid synthase activities in human hypothalamus

Abstract

Several data indicate that hypothalamic fatty acid synthesis pathway plays an important role in the control of food intake and energy expenditure in rodents. However, the confirmation of its physiological relevance in regulation of feeding in human remains incomplete. For fatty acid synthesis pathway to function as regulator of energy balance in human hypothalamus, acetyl-CoA carboxylase (ACC), fatty acid synthase (FAS) and other lipogenic enzymes activities must be present. The presence of FAS in human hypothalamic neurons has been shown by immunohistochemistry, but quantitative studies on FAS activity there has not been performed so far. There is no available data concerning ACC activity in human hypothalamus. Thus, we investigated ACC and FAS (as well as other lipogenic enzymes) activities in human hypothalamus of subjects who died in car accidents. The results presented in this paper indicate that ACC and FAS activities are present in human hypothalamus and that these activities are 2- to 3-fold lower than in rat hypothalamus. Moreover, our data presented in this paper indicate that other lipogenic enzymes activities are also present in human hypothalamus. The activity of FAS, ACC and other lipogenic enzymes in human hypothalamus suggests that fatty acid synthesis actively occurs there. Therefore, it is likely, that in human this pathway may be relevant to hypothalamic functioning as food intake and energy expenditure regulator, similarly as it was suggested in rodents.