URINARY TRYPSIN-INHIBITOR PREVENTS UTERINE MUSCLE-CONTRACTION BY INHIBITION OF CA++ INFLUX
URINARY TRYPSIN-INHIBITOR PREVENTS UTERINE MUSCLE-CONTRACTION BY INHIBITION OF CA++ INFLUX
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DOI：
10.1016/0002-9378(95)90189-2
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发表时间：
1995-07-01
影响因子：
9.8
通讯作者：
TERAO, T
中科院分区：
文献类型：
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作者：
KANAYAMA, N;ELMARADNY, E;TERAO, T
目的：本研究的目的是阐明尿胰蛋白酶抑制剂，Kunitz型蛋白酶抑制剂，在抑制子宫肌肉contraction.Study设计的作用机制：一个等长子宫收缩试验，研究这种抑制作用的尿胰蛋白酶抑制剂对子宫肌层。催产素、前列腺素F-2 α和脂多糖用于刺激子宫肌层收缩。在缓冲溶液中测量前列腺素F-2 α和E（2）。数字成像显微镜观察子宫平滑肌细胞钙离子内流情况。结果：用尿胰蛋白酶抑制剂或胎尿孵育后，催产素、前列腺素F-2 α或脂多糖刺激的子宫平滑肌收缩均被完全抑制。在等长收缩试验中，脂多糖刺激可显著增加缓冲液中甘草素F-2 α和E（2）的浓度，但当缓冲液中存在尿胰蛋白酶抑制剂时，甘草素F-2 α或E（2）的浓度无显著变化。尿胰蛋白酶抑制剂预孵育也抑制钙内流，导致平滑肌细胞内游离钙浓度没有检测到的变化。结论：我们提出，尿胰蛋白酶抑制剂从胎尿抑制子宫肌收缩通过调节细胞内Ca ++。
OBJECTIVE: The aim of this research was to elucidate the mechanism of action of urinary trypsin inhibitor, a Kunitz-type protease inhibitor, in suppressing uterine muscle contraction.STUDY DESIGN: An isometric uterine contraction test was used to study this inhibitory effect of urinary trypsin inhibitor on the myometrium. Oxytocin, prostaglandin F-2 alpha, and lipopolysaccharide were used to stimulate myometrial contraction. Prostaglandins F-2 alpha and E(2) were measured in the buffer solution. Influx of calcium into uterine smooth muscle cells was assessed by digital imaging microscopy.RESULTS: After incubation with urinary trypsin inhibitor or fetal urine, myometrial contractions stimulated by oxytocin, prostaglandin F-2 alpha or lipopolysaccharide were suppressed completely. The concentrations of prostaglandins F-2 alpha and E(2) in the buffer solution during the isometric contraction test were significantly increased by lipopolysaccharide stimulation, but when urinary trypsin inhibitor was present in the buffer solution the concentrations of prostaglandins F-2 alpha or E(2) did not change significantly. Preincubation with urinary trypsin inhibitor also inhibited calcium influx, resulting in no detectable change in the intracellular free calcium concentration of smooth muscle cells.CONCLUSION: We proposed that urinary trypsin inhibitor from fetal urine inhibits uterine muscle contraction by regulation of intracellular Ca++.