Ultrastructural changes of the hypertrophic epithelial cells in the thymus of splenectomized chickens.
Three weeks following the splenectomy of young chickens an increased number of the hypertrophic epithelial cells, which presented various signs of secretory activity, could be observed in the thymus. After splenectomy, these cells usually present a single, large-sized intracytoplasmic vesicle or vacuole lined with microvilli. The lumen of such vesicles is always full of granulated and membranous material. The ultrastructural appearance of the hypertrophic epithelial cells strongly suggests an intensive metabolic activity and a possible active protein synthesis. These results lead to the hypothesis that hypertrophic epithelial cells secrete a lymphopoietic hormones which is active in normal chickens and which is secreted at an accelerated rate during certain hyperfunctional circumstances such as the period following splenectomy.
D000818:Animals; D002645:Chickens; D003594:Cytoplasmic Granules / Q000648:ultrastructure; D004721:Endoplasmic Reticulum / Q000648:ultrastructure; D004848:Epithelium / Q000378:metabolism / Q000473:pathology / Q000648:ultrastructure; D005260:Female; D006984:Hypertrophy / Q000473:pathology; D008297:Male; D008928:Mitochondria / Q000648:ultrastructure; D013156:Splenectomy; D013950:Thymus Gland / Q000378:metabolism / Q000473:pathology* / Q000648:ultrastructure