Wiśniewska R, Wiśniewski K
Department of Pharmacology, Medical Academy of Białystok.
Rocz Akad Med Bialymst. 1996;41(2):183-90.
The influence of pentagastrin (PG) and its analogues: 3-leupentagastrin (3-leu-PG), 4-AspOBzl-pentagastrin (4-AspOBzl-PG), and of the cholecystokinin -terminal tetrapeptide (CCK-4) and its analogue CCK-4(Phet) on rat arterial blood pressure and isolated heart were studied. 4-AspOBzl-PG and CCK-4 (Phet) had no effect on the arterial blood pressure or the isolated heart. PG (1.0 microgram/kg iv), slightly raised the systolic and diastolic arterial blood pressure, whereas 3-leu-PG (1.0 microgram/kg iv) slightly lowered the systolic arterial blood pressure. 3-leu-PG (0.1 microgram/0.1 ml), like PG (0.1 microgram/ 0.1 ml) increased the contraction amplitude of the isolated heart and had no effect on the heart rate, but unlike PG, it had no effect on coronary outflow. CCK-4 (1.0 microgram/kg iv) slightly raised the systolic arterial blood pressure but, unlike cholecystokinin had no effect on the isolated heart. We conclude that shortening of the CCK chain to a C-terminal tetrapeptide reduces the positive inotropic effect. Blocking of one of the aspartic acid carboxyl groups by a benzyl radical in the 4 PG position eliminates the PG effect on the circulatory system. Substitution of metionine for leucine at the 3-PG position reduces the PG action on the circulatory system.
研究了五肽胃泌素（PG）及其类似物：3-亮氨酸五肽胃泌素（3-亮氨酸-PG）、4-苄酯天冬氨酸五肽胃泌素（4-苄酯天冬氨酸-PG），以及胆囊收缩素末端四肽（CCK-4）及其类似物CCK-4（苯丙氨酸）对大鼠动脉血压和离体心脏的影响。4-苄酯天冬氨酸-PG和CCK-4（苯丙氨酸）对动脉血压或离体心脏无影响。PG（1.0微克/千克静脉注射）可使动脉收缩压和舒张压略有升高，而3-亮氨酸-PG（1.0微克/千克静脉注射）可使动脉收缩压略有降低。3-亮氨酸-PG（0.1微克/0.1毫升）与PG（0.1微克/0.1毫升）一样，可增加离体心脏的收缩幅度，对心率无影响，但与PG不同的是，它对冠脉流量无影响。CCK-4（1.0微克/千克静脉注射）可使动脉收缩压略有升高，但与胆囊收缩素不同的是，它对离体心脏无影响。我们得出结论，将CCK链缩短至C末端四肽可降低正性肌力作用。在4-PG位置用苄基阻断天冬氨酸的一个羧基可消除PG对循环系统的作用。在3-PG位置用亮氨酸取代甲硫氨酸可降低PG对循环系统的作用。
