Effect of the Viscous Exudate of Mekabu (Sporophyll of Undaria pinnatifida) on Glucose Absorption in Rats

Abstract

The absorption of glucose in rats was investigated to elucidate the effect of ingesting the viscous exudate of mekabu on digestive absorption. A solution containing 10% dried viscous exudate of mekabu and 10% glucose was administered orally to rats. Changes in blood sugar levels were then measured as well as retention time of the contents in the stomach and small intestine using rats which had undergone surgery to connect the end of the ileum with the distal colon. It was found that the maximum blood sugar levels tended to be lower in the rats which had received the feed with viscous exudate than in those in a control group which had received the solution containing glucose only; this suggested that the ingestion of mekabu viscous exudate together with glucose suppressed the maximum blood sugar level. The retention time in the stomach and small intestine was longer in the group administered feed containing viscous exudate than in the control group. Movement of the contents from the stomach to the small intestine was delayed, which is presumed to be the cause of the suppressed rise in blood sugar level. The viscosity of viscous exudate samples prepared at 10°C and 80°C differed, and we also investigated whether or not this difference affected glucose absorption. Rats given the feed containing the viscous exudate prepared at 80°C, which had a higher viscosity, had lower maximum blood sugar levels than those ingesting the feed containing 10°C exudate. The retention time of the digestive tract contents was also longer, and the fecal weight and sugar amount in feces tended to be greater.