Eiler H, Armstrong-Backus C S, Lyke W A
Agricultural Experiment Station, University of Tennessee, Knoxville 37901.
Am J Physiol. 1989 Jul;257(1 Pt 1):E20-6. doi: 10.1152/ajpendo.1989.257.1.E20.
The desensitizing effects of oxytocin (OT) and prostaglandin F2 alpha (PGF2 alpha) were investigated in the uteri of rabbits. Uterine motility was measured in anesthetized rabbits infused intravenously with either PGF2 alpha (50 micrograms/min) or OT (100 mU/min) alternately. The treatment sequence was saline (30 min), first drug (OT or PGF2 alpha, 90 min), second drug (OT if PGF2 alpha was first drug and vice versa, 90 min), and first drug (repeated) 60 min. Both OT and PGF2 alpha infusions increased motility approximately 200% within 5-10 min. Thereafter, motility decreased linearly to base-line value. Fifty percent desensitization was completed at 35-45 min and 100% at 90 min. A tenfold increase in the infusion rate caused no further increase in motility. However, OT infusion into a PGF2 alpha desensitized uterus (and vice versa) elicited an immediate uterokinetic response. Oxygen consumption and glucose oxidation rate of uterine slices measured at different stages (preinfusion, maximal motility, and desensitized) of uterine motility showed no difference (P greater than 0.05) between the two experimental treatments. It was concluded that either OT or PGF2 alpha infusions specifically desensitized the uterus.
在兔子宫中研究了催产素（OT）和前列腺素F2α（PGF2α）的脱敏作用。在静脉注射PGF2α（50微克/分钟）或OT（100毫单位/分钟）的麻醉兔中交替测量子宫运动。治疗顺序为生理盐水（30分钟）、第一种药物（OT或PGF2α，90分钟）、第二种药物（若第一种药物为PGF2α则为OT，反之亦然，90分钟）以及第一种药物（重复）60分钟。OT和PGF2α输注均在5 - 10分钟内使运动增加约200%。此后，运动呈线性下降至基线值。50%脱敏在35 - 45分钟完成，100%在90分钟完成。输注速率增加10倍并未导致运动进一步增加。然而，向PGF2α脱敏的子宫中输注OT（反之亦然）会引发立即的子宫运动反应。在子宫运动的不同阶段（输注前、最大运动和脱敏）测量的子宫切片的耗氧率和葡萄糖氧化率在两种实验处理之间无差异（P大于0.05）。得出的结论是，OT或PGF2α输注均可使子宫特异性脱敏。
