GPT and metabolic dysfunction-associated steatotic liver disease: However, after ICV injection of AG receptor antagonist [D-Lys-3]-GHRP-6, serum TC, TGs, ALT, and AST decreased significantly when compared with those in the NAFLD group (P<0.05 or 0.01, Figures 2A and 2B), indicating a lipid-lowering and hepatoprotective activities of ICV injection of [D-Lys-3]-GHRP-6.