Ghrelin in small intestine, its contribution to regulation of food intake and body weight in cross-intestinal parabiotic rats.

Ghrelin has been shown to be associated with feeding behavior in humans and rodents. It has been suggested that ghrelin may play a role behind the effect of bariatric surgery. Inbred rats were made into parabiotic pairs so that they shared a single abdominal cavity. A further operation is performed later in which the small intestines are transected and re-connected so that one rat continually lost nutrition to its partner. Changes in food intake and body weight were recorded. Seven weeks later, content of ghrelin in the plasma, stomach and upper intestines were measured in the paired rats. Rats which lost nutrients to its counterpart (Loss rats) ingested significantly more food than sham control rats (p<0.001). Rats which gained nutrient (Gain rats) ingested less than controls (p<0.001). There was no significant difference in body weight, blood glucose, insulin, free fatty acids and triglycerides between the paired rats. There was significantly higher levels of ghrelin in the plasma (p<0.008) and the intestine of the Loss rats (p<0.02). There were no difference in ghrelin in the stomach between parabiotic rats and sham operated controls. The ghrelin content of the plasma and intestines were significantly higher in the Loss rats, which ate more, and normal in the Gain rats, which ate less than controls. Because no remarkable changes in the ghrelin content were observed in the stomach, difference in the quality of the chime may affect the local synthesis and release of ghrelin.