Quantitative estimation of islet tissue of pancreas in Spinifex hopping mouse (Notomys alexis)



Pancreases from three male and three female adult Spinifex hopping mice (Notomys alexis) were studied. No correlation was found between pancreas weight and body weight. Estimations of islet tissue mass and of individual cell types were made on paraffin sections of Bouin-fixed tissue taken from head, neck, body and tail regions of pancreas of each animal. Islet tissue mass was assessed using a linear scanning technique on sections stained with haematoxylin and eosin, and was compared with body weight. Specific cell types were assessed using a point-intercept method, on aldehyde-fuchsin-stained sections for beta (β) cells, and on immunoperoxidase labelled sections for alpha (α) cells (glucagon) and delta (δ) cells (somatostatin). Positive regional differences noted were a greater proportion of islet tissue in the tail region, and a lower proportion of α cells in the head region. Alpha cells were peripherally situated in the islets.

These results show some elements of agreement with a previously proposed hypothesis regarding the general patterns of arrangement of the mammalian endocrine pancreas.