Central lactate metabolism regulates food intake

1 Department of Physiology and 2 Department of Medicine, University of Toronto and 3 Toronto General Hospital Research Institute, University Health Network, Toronto, Ontario, Canada Submitted 30 May 2008 ; accepted in final form 17 June 2008 The central nervous system regulates food intake (FI) and body weight (BW), but the associated mechanisms remain to be elucidated. Here we report that central injections of lactate reduced FI and BW in rodents. Inhibition of central lactate metabolism to pyruvate with the lactate dehydrogenase inhibitor oxamate abolished the central effects of lactate on FI and BW. Conversely, central injections of pyruvate recapitulated the effects of lactate. Finally, inhibition of central lactate metabolism prevented the ability of circulating lactate to lower FI and BW. Together, the data indicate that activation of central lactate metabolism lowers FI and BW. central nervous system; obesity; diabetes Address for reprint requests and other correspondence: T. K. T. Lam, MaRS Centre, 101 College St., Toronto Medical Discovery Tower, Rm. 10-706, Toronto, ON, Canada M5G 1L7 (e-mail: tony.lam{at}uhnres.utoronto.ca )