Light and electron microscopic examinations of the pancreas in quails (Coturnix coturnix japonica)

SUMMARY The structure and ultra structure of the pancreas was investigated in this study in 20 healthy adult quails using histochemistry and electron microscopy. The quail pancreas inserted between the duodenal arms was divided into 4 lobes (dorsal, ventral, third and splenic lobes) and was anatomically relied to the ascendens duodenum by 3 main excretory ducts proceeding from the ventral, dorsal and the third lobes respectively. The pyramidal secretory cells exhibited a basal nucleus and a cytoplasm rich in rough endoplasmic reticulum (ER) and in zymogene granules and were regrouped into acini. Two cell types (dark and light acinus cells) were identified according to the profusion of ribosomes and polysomes (dark type) and to the aspect of the reticulum cisterns (broadened vesicles in the light type or narrower structure in the dark type). The endocrine cells were amassed into α, β and mixed islets: the α islets were mainly constituted by A and D cells and by C and PP cells at a lesser extend, the β islets principally contained B cells and few D and A cells in periphery and the mixed islets were characterized by the identification of all cellular types. The β islets were the most frequently found in the different lobes (from 53.23 ± 1.07% in the third lobe to 66.07 ± 0.93% in the ventral lobe), whereas the proportions of α- and mixed islets were weaker (from 26.20 ± 0.92% in the splenic lobe to 35.00 ± 0.79% in the third lobe and from 5.03 ± 0.50% in the ventral lobe to 11.77 ± 0.30% in the third lobe, respectively). However, α islets were bigger and less abundant in the splenic lobe than in the other lobes.