Immunohistochemical and morphometric study of the development of fetal and newborn rat pancreatic islets

OBJECTIVE: The aim of this study is to perform a detailed morphometric immunohistochemical study of the development of fetal and newborn rat pancreatic islets.

METHODS: Twenty-four pancreases were obtained from 19 and 21-day-old fetal rats, one and 4-day-old newborn rats. They were fixed in buffered neutral formalin, dehydrated and embedded in paraplast. Sections were stained with anti-insulin antibodies. A morphometric study was performed on the pancreatic islets at the Department of Anatomy, King Abdul-Aziz University, Jeddah, Kingdom of Saudi Arabia, between 2001 and 2002.

RESULTS: The volume density of B cells showed a gradual increase during the last days of gestation and a slight increase during the first 4 days after birth. All the other morphometric parameters showed a gradual increase during the last days of gestation and during the first days after birth. The B cell nuclear diameter and volume showed a slight increase after birth. The B cells were well stained and present in the central part of fetal and newborn islets, while, the other islet cells were present in the periphery of the islets.

CONCLUSION: The size of the endocrine tissue, which was represented by the islet diameter, islet volume, islet volume density, total number of islet cells, number of B cells and volume density of B cells showed a progressive increase during the perinatal period.