Schechter J, Goldsmith P, Wilson C, Weiner R
Department of Anatomy and Cell Biology, University of Southern California School of Medicine, Los Angeles 90033.
J Clin Endocrinol Metab. 1988 Oct;67(4):713-9. doi: 10.1210/jcem-67-4-713.
This study was undertaken to clarify the vascular anatomy of human prolactinomas and specifically to determine whether arteries were present. Sixteen prolactinomas were studied by electron microscopy. The presurgical diagnosis of the tumors as prolactinomas was based on the findings of hyperprolactinemia and radiographic abnormalities, and was confirmed by the electron microscopic features of the specimens as well as by immunocytochemical staining for PRL. In addition to the presence of fenestrated endothelial cells, which are characteristic of the normal capillaries of the anterior pituitary, 13 of the 16 prolactinomas contained arteries. These arteries ranged from well formed vessels with multiple layers of smooth muscle cells to abnormal terminal arterioles, i.e. vessels with fenestrated endothelium surrounded by a variable number of smooth muscle cells. Arteries were not found in anterior pituitaries from 8 patients with no pituitary disease. In the prolactinomas, smooth muscle cells also were found, either isolated in the pericapillary connective tissue space or in small cords some distance from the vessel lumen. The results suggest that vascular changes, including arteriogenesis, occur in prolactinomas (and possibly other types of pituitary tumor). The arteries entering the anterior pituitary directly could be congenital or develop during formation of the tumor. An arterial blood supply to a region of the anterior pituitary could result in the escape of that area from hypothalamic regulation, since systemic blood contains negligible levels of hypothalamic hormones. In the case of PRL-secreting cells, which are tonically inhibited by the hypothalamic hormone dopamine, this would result in hypertrophy, hyperplasia, and possibly tumorigenesis.
本研究旨在阐明人催乳素瘤的血管解剖结构，特别是确定其中是否存在动脉。通过电子显微镜对16例催乳素瘤进行了研究。肿瘤术前诊断为催乳素瘤基于高催乳素血症和影像学异常的发现，并经标本的电子显微镜特征以及PRL免疫细胞化学染色得以证实。除了存在有窗孔的内皮细胞（这是垂体前叶正常毛细血管的特征）外，16例催乳素瘤中有13例含有动脉。这些动脉范围从具有多层平滑肌细胞的结构良好的血管到异常的终末小动脉，即内皮有窗孔且周围有数量不等平滑肌细胞的血管。在8例无垂体疾病患者的垂体前叶中未发现动脉。在催乳素瘤中，还发现了平滑肌细胞，它们要么孤立于毛细血管周围结缔组织间隙中，要么位于距血管腔一定距离的小索状结构中。结果表明，包括动脉生成在内的血管变化发生在催乳素瘤（可能还有其他类型的垂体肿瘤）中。直接进入垂体前叶的动脉可能是先天性的，也可能在肿瘤形成过程中发育形成。垂体前叶某区域的动脉血供应可能导致该区域脱离下丘脑调节，因为全身血液中下丘脑激素的水平可忽略不计。对于受下丘脑激素多巴胺持续性抑制的催乳素分泌细胞而言，这将导致细胞肥大、增生，并可能引发肿瘤形成。
