Peptide immunoreactivity in developing entero-endocrine cells in endodermal grafts.

Presumptive endoderm was excised from 19-h chick or quail embryos and grafted, together with a fragment of notochord from a 48-h host chick embryo. After 14 days the graft showed differentiation towards several digestive and respiratory tract structures. Entero-endocrine cells were demonstrated in these structures. Peptide immunoreactivity in these structures was similar to some extent to the peptide spectrum in corresponding regions during normal development, though the number of demonstrable peptides per region under the conditions of grafting appeared to be higher than in control conditions.