Histological Study Of Age- Relatedchanges In The Spleen Of Albino Rats

Most of previous studies have focused on spleen and its clinicaldisorders. Studies of the changes in the cellular content of spleen duringits development were scarce. The present study was performed todescribe the histological and immunohistochemical changes in spleen ofalbino rats at different ages.Thirty male albino rats were used in this study and were classifiedinto three groups; A. B, C. Each group contained 10 animals.Group (A): Animals aged one day (Neonatal group).Group (B): Animals aged 3-6 months (Adult group).Group (C): Animals aged 18-20 months (Senile group).The animals were anesthetized using ether inhalation, and then thespleens were carefully dissected out. Small specimens were.andfixed in formol saline for 24 hours for light microscopic examination.Sections (5 um thick) were obtained, stained with H & E to study thegeneral structure of the spleen. Other sections were stained with silver tostudy the reticular framework of spleen. Immunohistochemicaltechniques were applied to study Tcells, B cells and dendritic cellsmorphology and distributions.Microscopic examination of a one day old albino rat spleenrevealed a very thin capsule covered with mesothelium. The parenchymawas mainly formed of red pulp while, the white pulp was represented byfew scattered dense accumulation of small lymphocytes. Megakaryocytesappeared as giant cells with multilobed nuclei and acidophilic cytoplasmdistributed in the red pulp.Examination of the adult group revealed thick capsule. The whitepulp was formed of periarterial lymphatic sheath and lymphoid follicles.