垂体生长激素分泌瘤细胞有关生长抑素调节的受体和受体后过程的某些变化  

Some variations of receptor and postreceptor transduction regulated by somatostatin in pituitary GH-secreting adenomas

作　　者：尹娟娟[1] 邓洁英[1] 史轶蘩[1] 任祖渊[1] 

机构地区：[1]北京协和医院

出　　处：《中国病理生理杂志》1996年第4期364-368,共5页Chinese Journal of Pathophysiology

基　　金：国家自然科学基金

摘　　要：为了解生长抑素（ＳＲＩＦ）在人垂体生长激素（ＧＨ）分泌瘤发病中的作用，在２５例肢端肥大症患者体外地养的垂体瘤细胞观察了ＳＲＩＦ激动剂（ＳＭＳ），抑制性鸟苷酸调节蛋白（Ｇｉ）拮抗剂百日咳毒素（ＰＴ）和钙离子载体Ａ２３１８７对ＧＨ分泌的影响．以及ＳＭＳ对细胞内ｃＡＭＰ水平的抑制作用。发现：ＳＭＳ可以使８４．０％（２１／１２５例）的ＧＨ瘤细胞ＧＨ分泌量明显抑制，揭示ＳＲＩＦ受体及受体后过程的功能基本正常；在３１．６％（６／１９例）患者的ＧＨ瘤细胞ＰＴ不能阻断ＳＭＳ对ＧＨ分泌的抑制作用，提示这些瘤细胞膜上Ｇｉ的功能异常；在３５．０％（７／２０例）用者的ＧＨ瘤细胞Ａ２３１８７未能拮抗ＳＭＳ对ＧＨ分泌的抑制作用，说明ＳＲＩＦ对Ｃａ￣（２＋）通道功能的调节有异常。在部分瘤细胞ＳＭＳ对ＧＨ分泌和细胞内ｃＡＭＰ的作用不一致。上述结果表明ＳＲＩＦ对垂体ＧＨ瘤细胞ＧＨ分泌的抑制作用由第二信使介导，但部分瘤细胞存在着受体后Ｇｉ和／或Ｃａ￣（２＋）通道功能的缺陷。In order to investigate the role of somatostatin(SRIF)on the pathogenesis ofhuman pituitary GH-secreting adenomas,the effects of the SRIF agonist SMS201-995(SMS),Gi protein inhibitor pertussis toxin(PT) and Ca(2+) ionophone A23187 on GH secretionin 25 cases of human pituitary GH adenomas in eell cuIture were observed.The effect ofSMS on intracellular cAMP level was also studied.Addition of 100nmol/L SMS to culturemedium of tumor cells caused a significant decrease of GH secretion in 21 out of 25 cases(84.0%) indicating that the function of SRIF reeeptor are normal.PT blocked theinhibitory effect of SMS 0n GH secretion in 13 out of 19 cases(68.4%),but not in theother 6 cases(31.6%)which may show abnormality in Gi.Ca(2+) ionophone A23187 did notabolish the SMS-indueed inhibition of GH release in 7 out of 20 cases (35%) demostratingabnomal function in Ca(2+) channel.It was observed that the actions of SMS on intracellularcAMP level and GH release were not consistent in 4 out of 10 cases of cultured GHadenoma cell tested.These results showed that cAMP and Ca(2+) are second messengersfor the action of SMS in about half pituitary GH adenomas,but the defects ofGi/Ca(2+) channel in certain cases may alleviate the inhibitory effect of SMS on GH secre-tion,it may be responsible to hypersecretion of those GH secreting adenomas.

关 键 词：垂体肿瘤 生长激素 腺苷环一磷酸 钙 

分 类 号：R736.402[医药卫生—肿瘤]