Histological and immunohistochemical studies on (adrenal gland) of immature and mature dogs

In this study, fourteen male dogs in two groups (immature and mature ages) used to study the histological structure of the adrenal gland and immunohistochemical reactions of vascular endothelial growth factor, Beta catenine, and Synaptophysin. Histologically the adrenal gland consisted of stroma and parenchyma, the capsule of immature dogs was delicate but thick at mature ages, and the cortex arranged into Zona Arcuta, Faciculata and Reticularis. Zona Arcuata arranged in arch-like structures that appeared more in the mature ages. Zona Faciculata arranged into cords of highly vacuolated cells than Zona Arcuata and Zona Reticularis and between these cords blood sinusoid appeared more in the immature one. The medullary cells arranged into follicles around blood sinusoids between cortical cells of immature glands , centrally localized in the glands of mature ages. Immunohistochemically, Vascular endothelial growth factor gave a strong reaction in cortical and medullary cells of immature ages and a moderate reaction in mature ones. Beta catenine gave a strong reactions in adrenal gland of immature ages and a weak reaction of immature ones. Synaptophysin gave a strong reaction in medulla of immature age and a weaker reaction in mature ones. From these results, we concluded that the Beta catenine localization associated with zonation of the adrenal gland of dogs and VEGF localization and higher expression in immature animals as related to angiogenesis of adrenal gland blood vessels. Similarly, the localization and expression of Synaptophysin in the medulla of immature animals might related to the neuroendocrine differentiation of developing medullary cells.