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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。
To understand the role of somatostatin (SRIF) in the pathogenesis of human pituitary growth hormone (GH) secretomas, SRIF agonists (SMS) were observed in pituitary tumor cells cultured in 25 patients with acromegaly in vitro. The effects of glycosylate (Gi) antagonist pertussis toxin (PT) and calcium ionophore A23187 on GH secretion. And the inhibition of intracellular cAMP levels by SMS. Findings: SMS can significantly inhibit 84.0% (21/125) of GH cell GH secretion, revealing normal function of the SRIF receptor and its receptors; 31.6% (6/19) The PT of GH cells in patients could not block the inhibition of GH secretion by SMS, suggesting abnormal function of Gi on the membrane of these tumor cells; A23187 of GH cells in 35.0% (7/20 patients) failed to antagonize SMS The inhibitory effect of GH secretion indicates that SRIF regulates the function of Ca ̄(2+) channel abnormally. The effect of SMS on GH secretion and intracellular cAMP in some tumor cells is inconsistent. The above results indicate that the inhibitory effect of SRIF on GH secretion in pituitary GH tumor cells is mediated by a second messenger, but some tumor cells have defects in the functions of post-receptor Gi and/or Ca 2+ channels.