Hormone secretion on several stages of tumorgenesity and growth rates of pituitary adenomas

1.用反向溶血空斑试验研究了正常雌性Fisher 344大鼠和雌激素(E_2)处理的雌性Fisher 344大鼠单个脑垂体细胞的催乳素(PRL)释放。在正常垂体细胞中，PRL的分泌呈多峰分布。相反，经E2处理的垂体细胞呈双峰型分布。随着E2处理时间的延长，单个垂体细胞分泌PRL的异质性降低。结论：1.雌二醇组垂体细胞的催乳素分泌量明显低于正常对照组。用细胞免疫印迹法检测单一分散的人生长激素分泌细胞分泌的生长激素释放激素(GHRH)。提示人GH腺瘤的自分泌生长和/或GHRH对GH分泌的局部调节作用。我们比较了多巴胺激动剂卡麦角林(CG)和溴隐亭(BC)对E_2诱导的大鼠垂体肿瘤…的抗肿瘤作用。更多的是在体外和体内。结果表明，CG对垂体细胞D2受体具有较高的亲和力，且在较低剂量下具有抗肿瘤作用。在人垂体腺瘤的生长速度方面，我们检测了内分泌功能、海绵窦侵袭性，并以抗增殖细胞核抗原(PCNA)和MIB1(一种新的抗Ki-67抗体)为标记物检测了生长速度。提示内分泌功能、海绵窦侵袭、生长速度是相互独立的生物学行为。作为一个新的发现，我们发现侵袭性腺瘤比非侵袭性腺瘤具有更高的IV型胶原溶解活性。因此，我们认为垂体腺瘤中IV型胶原酶的活性可能与其侵袭海绵窦的能力有关。在这一点上还需要进一步的审查。然而，我们已经开始通过细胞免疫印迹试验来检测人类垂体腺瘤分泌的一种IV型胶原酶-基质金属蛋白酶-9。较少

1. We studied prolactin (PRL) release from individual pituitary cells in normal and estrogen (E2) -treated female Fisher 344 rats by means of reverse hemolytic plaque assay. Multimodal distribution of PRL secretion was observed in normal pituitary cells. On the contrary, bimodal distribution was found in E2-treated pituitary cells. The heterogeneity of the PRL secretion from a single pituitary cell decreased in association with the length of E2 treatment. The PRL secretion of the E2-treated pituitary cells was less than that of the normal pituitary cells.2. Growth hormone-releasing hormone (GHRH) secreted by monodispersed human GH-producing pituitary adenoma cells was detected by the cell immunoblot assay. It is suggested that autocrinologic growth and/or local regulation of GH secretion by GHRH in human GH-producing pituitary adenomas.3. We examined an antitumoral effect of Cabergolinc (CG) , a dopamine agonist, with comparison to bromocriptine (BC) on E2-induced rat pituitary tumors … More In vitro and In vivo. The result suggests that CG has a higher affinity for the D2 receptor of pituitary cells and antitumor effect at a lower dosage than BC.4. On growth rates of human pituitary adenomas, we examined endocrinologic function, cavernous sinus invasion, and growth rates examined by using anti-proliferating cell nuclear antigen (PCNA) and MIB1 (a novel anti-Ki-67) as markers. The result suggest that endocrinologic function, cavernous sinus invasion, and growth rates are independent biologic behaviors each other.5. As a novel finding, on cavernous sinus invasion, we found that invasive adenomas had higher type IV collagenolytic activity than noninvasive adenomas. Thus, it is suggested that type IV collagenase activity in a pituitary adenoma may be related to its ability to invade the cavernous sinus invasion.6. Further examinations are needed on this points. However, we have already been started to examin matrix metalloproteinase-9, a type IV collagenase, secreted by human pituitary adenomas by means of the cell immunoblot assay. Less