DISTRIBUTION OF CELL TYPES OF THE ISLETS OF LANGERHANS IN THE PANCREAS OF THE ALBINO RATS

Abstract

The rat pancreas is an irregularly shaped, elongated organ extending between the duodenum and spleen.
OBJECTIVE: The distribution of the islets of Langerhans of the pancreas with different cell types in different
regions of the pancreas was observed in this study. SETTING: Basic Medical Science Institute, JPMC, Karachi.
MATERIAL & METHODS: 12 animals were included in present study. The animals were sacrificed under ether
anaesthesia. Tissues were processed and three microns thick sections were cut and stained with haematoxylin and
eosin and chrome-alum haematoxylin phloxine stain, examined under low and high magnifications of light
microscope. RESULTS: The study of the tissues showed greater number of the islets of Langerhans in the tail and
the body than in the head of the pancreas. No significant difference was observed in the size of islets. There were
more cells per islet in the tail than the head and the body. The alpha and the delta-cells were more abundant in the
head than in the body and the tail of the pancreas while the beta-cell were more abundant in the tail of the pancreas.
The mean nuclear diameter of the alpha and the beta-cell was more in the head and the body than in the tail while
the mean nuclear diameter of the delta-cell was more in the body than in the head and the tail and the alpha and the
delta-cells appeared to be larger than the beta-cell. The cytoplasm of the alpha, the beta and the delta-cell was
granular with centrally located round to oval nuclei. The present study showed that the alpha-cells were located
mostly at the periphery, the delta-cell at the junction of the centre and the periphery while the beta-cell were located
in the centre of the islets. CONCLUSION: The present study showed greater number of Islets of Langerhans in tail
and the body as compared to the head region. The alpha-cells were located at the periphery of islets, the delta-cells
were located at the junction of centre and the periphery, and the beta-cells were located mostly in the centre of islets.