缩胆囊素受体拮抗剂对血浆缩胆囊素生物测定的影响

利用生物法测定了102例正常人空腹及进食二个油煎鸡蛋30min后血浆CCK浓度,结果分别为1.4±0.1pmol/L和4.9±0.4pmol/L(X±SE)。血浆CCK浓度不随性别和年龄而变化。本文研究了三种不同类型的CCK受体拮抗剂对CCK生物测定的影响。一组将L364,718(5.0nmol/L),丙谷胺(1.0mmol/L)或Bt_2-cGMP(0.1mmol/L)分别加入含8pmol/LCCK-8的人血浆,用SEP-PAK提取,另一组先提取血浆,于测定前向血浆提取物内加入上述拮抗剂,两组同时测定。结果显示,在有L364,718存在时仍可利用生物法测定血浆CCK浓度,如血中含有丙谷胺或Bt_2-cGMP则无法准确测定。

EFFECT OF CCK RECEPTOR ANTAGONISTS ON PLASMA CCK BIOASSAY

Fasting and postprandial plasma CCK levels of 102 normal subjects weremeasured by bioassay with dispersed rat pancreatic acini. The referencevalucsranged from 0 to 4.2 pmol/L (CCK-8 equivalents) for fasting and from 1.1 to 13.5pmol/L for postprandial state. There was no significant difference between maleand female, or in different age groups. The effects of CCK receptor antagonistsof 3 different categories on CCK bioactivity in plasma measured by the bioassaywere investigated. L 364,718 (5 nmol/L), proglumide (1.0 mmol/L), or Bt_2-cGMP (0.1 mmol/L) was either extracted by SEP-PAK C18 cartridges togetherwith human plasma containing 8 pmol/L of CCK-8, or added into the plasma ex-tracts before the assay. The CCK bioactivity was inhibited by all of the 3 CCKantagonists. The action of L364, 718 could be eliminated by the procedure of plas-ma extraction, but not of proglumide or Bt_2-cGMP. It was suggested that CCKbioassay can be used even if L364,718 was administered. However, CCK cannotbe measured accurately if there are proglumide or Bt_2-cGMP in the plasma.