Ghrelin, an endogenous ligand for the growth hormone secretagogue receptor, has been detected in the thymus of multiple vertebrates. However, little is known about its distribution in the thymus of the African ostrich. In this study, we evaluated the distribution and morphological characteristics of ghrelin-producing cells in the thymus of the African ostrich. Our results revealed that the thymus consists of a capsule and a parenchyma, which comprises the cortex and medulla. Compared to the cortex, the medulla had a fewer number of thymocytes and a greater number of epithelial cells. Additionally, three thymic corpuscles were identified. Ghrelin- immunopositive (ghrelin-ip) cells were detected both in the cortex and medulla of the African ostrich thymus, specifically within epithelial cells and thymic corpuscles. On the other hand, no ghrelin-ip cells were detected within thymocytes. These results clearly demonstrate the presence of ghrelin-ip cells in the thymus of the African ostrich.
KEY WORDS: African ostrich; Ghrelin; Thymus; Immunohistochemistry.