Action of sex-hormones on pancreatic islet function in female domestic duckling.

The aim of the present study was to examine the action of sex-hormones on the endocrine pancreas of the female domestic duckling. Estrogen alone, or in combination with progesterone, inhibited mitosis and caused degranulation only in the B-cells of the pancreatic islets. A- or D-cells of the islets were not affected. Progesterone alone had no effect on any islet cells. It is suggested that estrogen may have dual action (mitotic inhibition and beta cell stimulation) only on B-cells of the pancreatic islets of the domestic ducklings.