抄録
To investigate whether stimulatory effect of ghrelin on food intake and inhibitory effect of leptin on gaining body weight are modified by cholecystokinin (CCK), levels of ghrelin, leptin and CCK in circulatory blood were measured by ELISA method at 7 and 38 weeks old of male Otsuka Long-Evans Tokushima Fatty (OLETF) rats and its normal counterpart of male Long-Evans Tokushima Otsuka (LETO) rats. The averaged body weight of OLETF rats and levels of active ghrelin and leptin in OLETF rats were significantly increased as compared to those of LETO rats. Level of CCK of OLETF rats were significantly decreased as compared to those of LETO rats. Multiple linear regression analysis demonstrated that the ratio of active ghrelin to desacyl ghrelin was a significant determinant for food intake in OLETF rats and that leptin was a significant determinant for body weight in LETO rats. The ratio of the difference in the amount of food intake between the ages of 7 and 38 weeks to the difference in levels of active ghrelin between the ages was increased when CCK was decreased. The ratio of the difference in body weight between the ages to the difference in levels of leptin between the ages was increased when CCK was decreased. Thus, the decreased level of CCK in OLETF rats augment the effect of ghrelin on feeding and the inhibitory effect of leptin on gaining body weight, simultaneously. In OLETF rats, the effect of ghrelin may dominate that of leptin, resulting in obesity. [J Physiol Sci. 2007;57 Suppl:S89]
