Cellular and sub-cellular localisation of oxyntomodulin-like immunoreactivity in enteroendocrine cells of human, mouse, pig and rat

Abstract

We use a monoclonal antibody against the C-terminal of oxyntomodulin (OXM) to investigate enteroendocrine cells (EEC) in mouse, rat, human and pig. This antibody has cross-reactivity with the OXM precursor, glicentin (Gli) but does not recognise glucagon. The antibody stained EEC in the jejunum and colon of each species. We compared OXM/Gli immunoreactivity with that revealed by antibodies against structurally related peptides, GLP-1 and glucagon and against GIP and PYY that are predicted to be in some EEC that express OXM/Gli. We used super-resolution to locate immunoreactive vesicles. In the pancreas, OXM/Gli was in glucagon cells but was located in separate storage vesicles to glucagon. I..