increase in expression similar to that observed in mice (Saladinet al., 1995), leptin-a mRNA levels did not change upon long-term fasting for up to six weeks (Huising et al., 2006a). This links the
liv er to the regulation of short-term food intake in teleostean fish.Together with the gut, the liver is a logical place to integrate information regarding food intake, as it directly receives blood from the gut via the portal vessel system, and the increase in leptin-a follows the post-prandial increase in glucose and drop in non-esterified fatty acids (NEFA) (Huising et al., 2006a). If the increa se in leptin-a expression is regulated directly via nutrients, or via other (humoral) regulators such as insulin or cholecystokinin(CCK) remains unanswered.