[Immunohistological study of the expression of glucagon in dorsal pancreatic endoderm in the early chick embryo].

An immunohistological study demonstrated that glucagon first appears in the dorsal pancreatic endoderm of the chick embryo at stage 16 of Hamburger and Hamilton during normal development. It was also shown that the self-differentiation potency of the isolated dorsal endoderm to express glucagon in vitro in the absence of adjoining tissues appears at stage 11.