Rápido controle da Diabetes pode estar associado a neoglucogenese intestinal
Rapid Control of Diabetes After Gastric Bypass Linked to Intestinal Gluconeogenesis
NEW YORK (Reuters Health) Sept 02 – The results of an animal study suggest that the rapid and substantial diabetes control seen after Roux-en-Y gastric bypass surgery is due, at least in part, to increased intestinal gluconeogenesis.
When the liver senses the increased glucose level in the portal vein, it reduces its own production of the sugar. Since the liver contributes much more to the body's overall glucose production than do the intestines, the net effect is enhanced glucose control.
The increase in intestinal glucose formation was only noted with gastric bypass, not with gastric banding, which may explain why only the former has been associated with enhanced diabetes control, French researchers report in the September 3rd edition of Cell Metabolism.
Besides removing a substantial portion of the stomach, gastric bypass reorganizes the intestines into two parts, study co-author Dr. Gilles Mithieux, from Universite de Lyon, said in a statement. The proximal portion no longer receives nutrients directly from the stomach, whereas the more distal portion of the intestines now receives direct output from the stomach.
These changes, according to Dr. Mithieux, cause an increase in glucose production. Specifically, the lower portion, which usually produces little glucose, increases its production, more closely resembling the upper portion in this regard. Sensors in the liver detect the elevated glucose and send an appetite-suppressing signal to the brain, which contributes to the satiety and weight loss seen with gastric bypass.
In the current investigation, the authors examined the effects of gastric bypass and gastric banding in mice. In addition to the link between gastric bypass and intestinal gluconeogenesis, they found that a glucose transporter called GLUT-2 is needed for the liver to sense glucose levels in the portal vein. Mice lacking GLUT-2 did not experience the enhanced glycemic control usually seen after gastric bypass.
Cell Metabolism 2008;8:201-211.
Fonte : reuters health information