Argyrophilic and glucagon-immunoreactive cells in the ileum and colon of the developing opossum Didelphis albiventris (Marsupialia)

Abstract

The ontogenesis of glucagon-producing cells of the ileum and colon of pouch young and of weaned and adult opossums Didelphis albiventris was studied in comparison with the endocrine argyrophilic cell population development. In the ileum, the mean population of argyrophilic cells/mm(2) increased with ontogenesis from 122.9 +/- 18.7 in the pouch young to 211.4 +/- 48.9 in adult animals, while the number of glucagon-immunoreactive cells/mm(2) remained practically constant, i.e. 29.2 +/- 7.3 in the pouch young and 28.1 +/- 5.0 in the adult animal. In the colon, the population of argyrophilic cells/mm(2) remained constant throughout ontogenesis, i.e. 45.8 +/- 6.2 in the pouch young and 48.9 +/- 10.4 in the adult animals. In turn, the enteroglucagon-producing cells increase in number from 4.5 +/- 2.9 to 14.6 +/- 5.2 cells/mm(2) from the pouch young to the adult. We conclude that the intestinal glucagon-producing cells of D. albiventris present a differentiated development in the ileum and colon. This fact suggests that glucagon-immunoreactive cells may play a distinct role in these segments of the intestine during ontogenesis.