TGRI's Dr. Tony Lam and his team have uncovered important findings that could help explain how glucose (sugar) production and blood sugar levels are regulated in healthy and obese/diabetic individuals. These findings have important implications for future therapies using glycine or a glycine analogue to lower blood sugar levels in diabetes and obesity.

"We've been able to show that delivery of glycine activates, or turns on, specific brain receptors and triggers a brain-liver axis of communication to lower sugar production," explains Dr. Lam. "Our studies demonstrated for the first time not only that a region of the brain called dorsal vagal complex (DVC) is sufficient to lower blood sugar levels, but that the signal(s) in the DVC can be activated by glycine."

Using animal model, the team used several approaches to show that activating the NR1 (glycine binding site) and NR2 subunits of NMDA receptors in the DVC--receptors responsible for brain cell communication--lowers sugar production and blood sugar levels. Future studies will look towards testing glycine effects in multiple diabetic and obese models as well as discovering new activators of NMDA receptors that could potentiate the glucose-lowering effect in diabetes and obesity. Clarifying the role of NMDA receptors in the DVC that relay gut signals to lower blood sugar levels is also important future research.

Lam CK, Chari M, Su BB, Cheung GW, Kokorovic A, Yang CS, Wang PY, Lai TY, Lam TK. J Biol Chem. 2010 May 6. [Epub ahead of print]. [Pubmed abstract]. Research supported by the Canadian Institutes of Health Research, the Banting and Best Diabetes Centre and the University of Toronto, the John Kitson McIvor Endowed Chair in Diabetes Research,and the Canada Research Chairs Program.