1Department of Anatomical Sciences, School of Veterinary Medicine, University of Shiraz, Shiraz, Iran
2Graduated from School of Veterinary Medicine, University of Shiraz, Shiraz, Iran
In the present study, pancreas glands in Mehraban breed of female sheep were histomorphometrically studied in four different age groups included: fetus, newborn, sexually mature and old ages. The results of histomorphometrical analysis with regard to frequency and percentage of parenchymal and stromal structures such as, exocrine secretory units, secretory ducts, blood vessels, islets of Langerhans and stromal connective tissue showed that minimum and maximum percentages of structures within the whole gland belonged in fetal stage, to blood vessels and stromal connective tissue; newborn stage, to blood vessels and exocrine secretory units; in sexually mature, to islets of Langerhans and exocrine secretory units and in old stage, also to islets of Langerhans and exocrine secretory units, respectively. The diameter changes of islets of Langerhans in different age groups from minimum to maximum were included: fetus, old, sexually mature and newborn stages. In comparison between different age groups, the frequency of exocrine secretory units showed a significant increase from fetal stage to newborn, sexually mature and old stages (P<0.05). On the other hand, there was a significant decrease in frequency of secretory ducts from fetal stage to newborn, sexually mature and old stages and there was also a significant decrease in frequency of blood vessels from fetal to newborn stage (P<0.05). Significant decrease was also observed in frequency of islets of Langerhans from fetal and newborn stages to sexually mature and old stages. In comparison between groups, there was a significant increase in diameter of islets of Langerhans from fetal to newborn and sexually mature stages and decrease from newborn to sexually mature and old stages. Our study revealed that, there was no significant difference in parenchymal and stromal structures and diameter of islets of Langerhans between different parts of the gland in each age group. However, the above mentioned parameters often showed significant differences between different age groups. These differences were more prominent between fetal stage compared to the other age groups. Therefore, it can be concluded that structural changes of parenchyma and stroma of pancreas gland begin from pre-natal period and will proportionally continue during the period of post-natal development.