The developmental plasticity of colocalization pattern of peptide YY and glucagon-like peptide-1 in the endocrine cells of bovine rectum

Abstract

Peptide YY (PYY) and glucagon-like peptide-1 (GLP-1) are produced in endocrine cells that show distal distribution in each of small and large intestine. They are colocalized in the same endocrine cells at different ratios depending on the animal species. The present study examined the possibility of plasticity in the colocalization pattern in the bovine rectum, which is known to contain endocrine cells at a high concentration. Consecutive sections from different pre- and postnatal stages were stained immunohistochemically. The immunoreactive (IR) cells were divided into three groups: 1) cells IR for both PYY and GLP-1 (PYY/GLP-1-IR cells), 2) cells IR only for PYY (PYY-IR cells), and 3) cells IR only for GLP-1 (GLP-1-IR cells). The percentage of PYY/GLP-1-IR cells was high in the prenatal (early, mid- and late fetuses) and suckling stages, whereas it decreased in the herbivorous (weaning, weaned and adult) stages. In contrast, percentages of PYY and GLP-1-IR single cells were low in the prenatal and suckling stages and increased after the suckling stage. PYY/GLP-1 endocrine cells may adapt to the change of digestion depending on feeding habits and/or specific developmental stages of cattle. The present results suggest the developmental plasticity of the colocalization pattern of gut hormones with nutritional transition.