THE ROLE OF CALCIUM ION IN THE PATHOGENESIS OF HUMAN PITUITARY GH－SECRETING ADENOMAS

ＴＨＥＲＯＬＥＯＦＣＡＬＣＩＵＭＩＯＮＩＮＴＨＥＰＡＴＨＯＧＥＮＥＳＩＳＯＦＨＵＭＡＮＰＩＴＵＩＴＡＲＹＧＨ－ＳＥＣＲＥＴＩＮＧＡＤＥＮＯＭＡＳＤｅｎｇＪｉｅｙｉｎｇ（邓洁英）；ＳｈｉＹｉｆａｎ（史轶蘩）ａｎｄＹｉｎＪｕａｎＪｕａｎ（尹娟娟）（Ｄｅｐ...

THE ROLE OF CALCIUM ION IN THE PATHOGENESIS OF HUMAN PITUITARY GH-SECRETING ADENOMAS

To study the role of Ca2 in the pathogenesis of pituitary growth hormone secreting adenomas, the function of Ca2 in 23 cases of human Prturtary GH-secreting adenoma was investigated in monolayer cell culture. It was found that Ca2 channel blockers nicardipin and nifedipin inhibrted basal and growth hormone releasing hormone (GRH)stimulated GH secretion in 87. 5 % and 100. 0 % of the GH adenomas . respectively, demonstrating that in most human pituitary GH adenomas, the basal and GRH regulated GH secretion is Ca2 dependent. The GRH and sometostatin (SRIF) agonist octreotide regulated the processes of GH secretion via Ca2 had defects in different steps including receptor ,postreceptor Ca2 channel and Ca2 GH secreting coupling in 6 (66. 6%) and 5 (55. 5 % ) cases of 9 GH adenomas respectively. Among them,the defects in GRH receptor and SRIF regulated Ca2 channel are the main causes of the dysfunction of GH adenomas. These defects may be related to GH hypersecretion in GH adenomas. Our data provides advance evidences for intrinsic defects of GH adenomas.