Ławnicka Hanna, Pisarek Hanna, Kunert-Radek Jolanta, Pawlikowski Marek
Department of Immunoendocrinology, Chair of Endocrinology, Medical University of Lodz, Poland.
Neuro Endocrinol Lett. 2008 Feb;29(1):113-6.
The aim of the study was to examine the effect of somatostatin (SST) on vascular endothelial growth factor (VEGF) secretion from clinically non-functioning pituitary tumors incubated in vitro.
Eight pituitary tumors surgically removed were investigated. All of the tumors were diagnosed before surgery as non-functioning. Seven of them were diagnosed after surgery as pituitary adenomas and expressed either gonadotropins or their subunits as detected by immunohistochemistry. Two tumors additionally expressed prolactin and growth hormone. One tumor was immunonegative for pituitary hormones and was diagnosed as haemangiopericytoma. All tumors but one were investigated immunohistochemically to detect the somatostatin receptors and expressed at least 3 of 5 subtypes of somatostatin receptors. The cells isolated from the examined tumors were exposed in vitro to native SST-14. The concentration of VEGF in the culture media was performed by means of ELISA method.
It was found that the exposure on SST-14 resulted in the divergent changes (increase in 4 cases and decrease in 3 cases) in VEGF concentrations in the medium. It seems that the inhibition of VEGF secretion is related to the expression of somatostatin receptor subtypes sst1 and sst2.
The response of VEGF secretion from pituitary tumoral cells to SST seems to depend on the spectrum of expressed somatostatin receptor subtypes. However, this presumption needs further studies on the larger material.
本研究旨在探讨生长抑素（SST）对体外培养的临床无功能垂体瘤血管内皮生长因子（VEGF）分泌的影响。
对手术切除的8例垂体瘤进行研究。所有肿瘤术前均诊断为无功能肿瘤。其中7例术后诊断为垂体腺瘤，免疫组化检测显示表达促性腺激素或其亚基。另外2例肿瘤还表达催乳素和生长激素。1例肿瘤垂体激素免疫阴性，诊断为血管外皮细胞瘤。除1例肿瘤外，所有肿瘤均进行免疫组化检测生长抑素受体，表达至少5种生长抑素受体亚型中的3种。从所检查的肿瘤中分离出的细胞在体外暴露于天然SST-14。通过ELISA法检测培养基中VEGF的浓度。
发现暴露于SST-14导致培养基中VEGF浓度出现不同变化（4例升高，3例降低）。VEGF分泌的抑制似乎与生长抑素受体亚型sst1和sst2的表达有关。
垂体瘤细胞VEGF分泌对SST的反应似乎取决于所表达的生长抑素受体亚型谱，但这一推测需要对更多样本进行进一步研究。
