Effects Of Aging On Pancreatic Islet Cell Function : An Experimental Immunohistochemical And Ultrastructural Study

Abdel-Rahman, Ahmed H.; Hassan, Hassan Abdel-Hady; Kasem, Mohamed A.; Osman, Hosam El-Din H.; Abdel-Hamid, Hanan S.; El- Basil, Mohamed; Mashahit, Mohammed A.

doi:10.21608/ejhm.2007.17703

Effects Of Aging On Pancreatic Islet Cell Function : An Experimental Immunohistochemical And Ultrastructural Study

Document Type : Original Article

Authors

¹ Departments of Pathology Al-Azhar Faculty of Medicine (Assuit& Cairo)

² Histology Al-Azhar Faculty of Medicine (Assuit& Cairo)

³ Anatomy Al-Azhar Faculty of Medicine (Assuit& Cairo)

⁴ Departments of Pathology Kasr El-Aini Faculty of Medicine (Cairo)

⁵ Internal Medicine Kasr El-Aini Faculty of Medicine (Cairo)

⁶ Department of Internal Medicine Al-Fayoum University.

10.21608/ejhm.2007.17703

Abstract

A strong relationship between aging and diabetes mellitus has been clinically suggested, however, none of the previous published data had clearly focused on the age-related cytomorphological changes in the pancreas which are the goal of this study.Three groups of male apparently healthy rabbits have been used, ten animals each; classified as group-1 (3- 5months old); group-2 (9-12 months old) and group-3 (24-36 months old). After sacrification, sections from the pancreas were stained by Haematoxylin and Eosin (H&E), Gomori trichromic stain & ultrastructurally to detect aging histologic changes as well as immunohistochemically to identify insulin and glucagon secreting cells using their appropriate monoclonal antibodies .
A progressive histological distortion with fibrosis and fatty changes were directly proportional to age, being mild in group-2 and severe in group-3. Morphometric studies by computerized image analysis showed that the mean number of islets was significantly higher in group2 (8.98±1.51), lowest in group-1 (5.08±1.48) and intermediate in group-3 (6.37±1.37). The mean diameter and square area of islets were significantly higher in group-2 compared to other groups (P< 0.05). The mean number of  cells per islet & their secretary granules were significantly (P <0.05) higher in group-2, intermediate in group-1 and lowest in group-3.In contrast, the mean number of cells per islet and their secretory granules were insignificantly (P< 0.05) higher in group -2, intermediate in group-3 and lowest in group-1.Also, the / ratio ( cells/ cells) was greatest in group-2 (3.059:1), intermediate in group-1 (3.37:1), and lowest in group-3 (2.479:1).
The increased number of  cells may be due to a compensatory process to correct the hormonal feedback mechanism of insulin .The results of this work suggest that  cells are generally more vulnerable to aging, an observation which might be correlated clinically with higher incidence of diabetes in older ages.