Sánchez-Gurmaches et al. (2010), using [1-14C]-oleic acid, found that IGF-I was also capable to induce fatty acid uptake and oxidation on rainbow trout myocytes more efficiently than insulin. In fact, fatty acid oxidation appeared to be more sensitive to insulin and IGF-I than glucose oxidation in those experiments. Planas et al. (2000) characterized IGF-I receptors in rainbow trout adipose tissue, and Albalat et al. (2005a, 2005b) investigated the endocrine regulation of lipid metabolism in this tissue using isolated adipocytes, both from rainbow trout and gilthead sea bream, although more research in the control of fat accumulation and mobilization in fish seems necessary. In an in vivo study, Gómez-Requeni et al. (2012) reported the correlation of the growth hormone (GH)/IGF axis and lipid diets in pejerrey juveniles.