Saitoh Y, Arita N, Ohnishi T, Ekramullah S, Takemura K, Hayakawa T
Department of Neurosurgery, Osaka University Medical School, Japan.
Acta Neurochir (Wien). 1997;139(9):851-6. doi: 10.1007/BF01411403.
Octreotide is a potent agonist of somatostatin that lowers the serum level of growth hormone (GH), and reduces the size of somatotropinomas. However, the detailed mechanism of shrinkage of this tumour is not known. We, therefore, evaluated 11 patients with somatotropinomas who were treated with octreotide 300 micrograms/day for 2-5 weeks to observe the morphological changes in the tumour using electron microscopy and the immunocytochemical study of apoptosis using polyclonal anti-single stranded DNA. Findings were compared with those obtained with bromocriptine treatment (10 mg/day, 2 weeks) of 5 patients with somatotropinomas, and 11 patients who received no preoperative treatment (control group). The octreotide group showed neither increase in stromal tissue nor cell death. The size of tumour cells appeared to be slightly reduced. No typical apoptotic bodies were seen on the electron micrographs. The apoptotic index in the octreotide group (0.40 +/- 0.60%; mean +/- SD) resembled that in the control group (0.81 +/- 0.79%). In contrast, the bromocriptine group showed some cell death and an increase in stromal tissue. The bromocriptine group also showed the apoptotic index which (20.1 +/- 14.8%) was significantly higher than that of the control group (0.81 +/- 0.79%). Thus, octreotide did not induce apoptosis in somatotropinomas despite the presence of tumour shrinkage. Because of the lack of fibrosis observed in the octreotide-treated tumours, the preoperative administration of octreotide may help to improve the outcome of the transsphenoidal operation.
奥曲肽是一种强效的生长抑素激动剂，可降低血清生长激素（GH）水平，并缩小生长激素瘤的大小。然而，这种肿瘤缩小的详细机制尚不清楚。因此，我们评估了11例生长激素瘤患者，他们接受每天300微克奥曲肽治疗2 - 5周，使用电子显微镜观察肿瘤的形态变化，并使用多克隆抗单链DNA对细胞凋亡进行免疫细胞化学研究。将结果与5例接受溴隐亭治疗（每天10毫克，2周）的生长激素瘤患者以及11例未接受术前治疗的患者（对照组）的结果进行比较。奥曲肽组既没有间质组织增加也没有细胞死亡。肿瘤细胞的大小似乎略有减小。在电子显微镜照片上未见到典型的凋亡小体。奥曲肽组的凋亡指数（0.40±0.60%；平均值±标准差）与对照组（0.81±0.79%）相似。相比之下，溴隐亭组出现了一些细胞死亡和间质组织增加。溴隐亭组的凋亡指数（20.1±14.8%）也显著高于对照组（0.81±0.79%）。因此，尽管肿瘤缩小，但奥曲肽并未诱导生长激素瘤细胞凋亡。由于在接受奥曲肽治疗的肿瘤中未观察到纤维化，术前给予奥曲肽可能有助于改善经蝶窦手术的结果。
