Growth Hormone Overexpression Induces Hyperphagia and Intestinal Morphophysiological Adaptations to Improve Nutrient Uptake in Zebrafish

Graphical AbstractGH overexpression increases the intestinal mass and absorptive surface area both through the direct effects of GH transgenics (up-regulating the expression of its cognate receptor and insulin-like growth factor, igf1a) and through indirect effects through an increase in the amount of food consumed. In addition, hyperphagia provides a greater amount of nutrients in the intestinal lumen and stimulates the synthesis of di- and tri-peptide transporters, which are the main route of absorption of dietary products from protein degradation.