Development of fetal rat pancreatic islet A cells. A quantitative and immunocytochemical study

OBJECTIVE: To perform a detailed quantitative immunocytochemical study of the development of fetal rat pancreatic islet A cells.

METHODS: Pancreases were obtained from 19 and 21-day- old fetal rats. Ten rats were used per each group. Non-fasting blood glucose levels were measured to confirm that the animals were normoglycemic. The pregnant rats were anesthetized by ether inhalation, and the fetuses were removed from their uteruses. They were fixed in buffered neutral formalin, dehydrated and embedded in paraplast and serially sectioned (5 um). We examined 32-48 islets (8-12 per section) for each fetus. Sections were stained by avidin biotin complex technique. A quantitative study was performed on the pancreatic islet A cells. Carl Zeiss software from Zeiss was used in this study. This study was carried out at the Department of Anatomy, King Abdul-Aziz University, Jeddah, Kingdom of Saudi Arabia during the period January to December 2005.

RESULTS: The volume density and the number of A cells showed a significant increase during the last days of gestation. All other parameters showed a significant increase during the last days of gestation. The A cell nuclear diameter and volume did not increase significantly during the last days of pregnancy. The A cells were well stained and occupied the peripheral part of the islets.

CONCLUSION: The present study represented a detailed quantitative immunohistochemical study and demonstrated that the size of the endocrine tissue and the islet A cells increased significantly during the last days of gestation.