摘要
Pituitary tumours are the cause of hyperadrenocorticism in a variety of species, but the role of the pituitary gland in hyperadrenocorticism in ferrets is not known. In this species, the disease is mediated by the action of excess gonadotrophins on the adrenal cortex and is characterized by an excessive secretion of sex steroids. In this study, the pituitary gland of four healthy control ferrets, intact or neutered, and 10 neutered ferrets with hyperadrenocorticism was examined histologically following immunohistochemical labelling for adrenocorticotrophic hormone, α-melanocyte-stimulating hormone, growth hormone, thyroid-stimulating hormone, luteinizing hormone, follicle-stimulating hormone, and prolactin. Immunohistochemistry revealed that somatotrophs, thyrotrophs and lactotrophs were the most abundant cell types of the pars distalis of the pituitary gland in the healthy ferrets. The distribution of corticotrophs was similar to that in the dog and man. In ferrets, as in dogs, the melanotrophic cell was almost the only cell type of the pars intermedia. Gonadotrophs were found in the pars distalis of neutered, but not intact ferrets. All the ferrets with hyperadrenocorticism had unilateral or bilateral alterations of the adrenal gland. In addition, in the pituitary gland of two of these ferrets a tumour was detected. These tumours were not immunolabelled by antibodies against any of the pituitary hormones, and had characteristics of the clinically non-functional gonadotroph tumours seen in man. In some of the other ferrets low pituitary immunoreactivity for gonadotrophic hormones was detected, which may have been due to the feedback of autonomous steroid secretion by the neoplastic transformation of the adrenal cortex. It is concluded that initially high concentrations of gonadotrophins resulting from castration may initiate hyperactivity of the adrenal cortex. The low incidence of pituitary tumours and the low density of gonadotrophin-positive cells in non-affected pituitary tissue in this study suggest that persistent hyperadrenocorticism is not dependent on persistent gonadotrophic stimulation.
摘要译文
垂体肿瘤是多种物种中过度肾上腺皮质激素的原因，但垂体腺在雪貂的超肾上腺皮质激素中的作用尚不清楚。在这个物种中，该疾病是由过量促性腺激素对肾上腺皮质的作用介导的，其特征是性类固醇分泌过多。在这个研究中，四个健康对照雪貂的脑垂体，完整或绝育，免疫组织化学标记肾上腺皮质激素，α-黑素细胞刺激素后，组织学检查了10只患有高肾上腺皮质激素的绝育雪貂，生长激素，促甲状腺激素，黄体生成素，卵泡刺激素和催乳素。免疫组织化学揭示了生长激素，促甲状腺激素和营养缺陷型是健康雪貂脑垂体远端最丰富的细胞类型。促肾上腺皮质激素的分布与狗和人的分布相似。在雪貂中，如在狗中，致病细胞几乎是中间体的唯一细胞类型。在绝育但不完整的雪貂的远端部分发现了促性腺激素。所有患有高肾上腺皮质激素的雪貂都有肾上腺的单侧或双侧改变。此外，在其中两只雪貂的垂体中检测到肿瘤。这些肿瘤未被任何垂体激素的抗体免疫标记，并且具有在人中看到的临床上无功能的促性腺激素肿瘤的特征。在一些其他雪貂中检测到促性腺激素的低垂体免疫反应性，这可能是由于肾上腺皮质的肿瘤转化引起的自主性类固醇分泌的反馈。结论是，由阉割引起的最初高浓度的促性腺激素可引起肾上腺皮质的过度活跃。在这项研究中，未受影响的垂体组织中低密度的促性腺激素阳性细胞表明持续性高肾上腺皮质激素不依赖于持续的促性腺激素刺激。
N.JSchoemaker[a];M.Hvan der Hage[b];GFlik[c];J.TLumeij[a];ARijnberk[d];. Morphology of the Pituitary Gland in Ferrets (Mustela putorius furo) with Hyperadrenocorticism[J]. Journal of Comparative Pathology, 2004,130(4): 255-265