Peuhkuri K, Nevala R, Vapaatalo H, Moilanen E, Korpela R
Institute of Biomedicine, Department of Pharmacology and Toxicology, University of Helsinki, Finland.
Aliment Pharmacol Ther. 1999 Sep;13(9):1227-33. doi: 10.1046/j.1365-2036.1999.00608.x.
Clinical symptoms during lactose tolerance test mimic those seen after therapeutic administration of prostaglandins, and resemble inflammatory processes.
To investigate the possibility that lactose-induced gastrointestinal symptoms are associated with prostaglandins and/or nitric oxide.
After an overnight fast, nine maldigesters ingested lactose or sucrose with or without an inhibitor of prostaglandin synthesis (ibuprofen), in a randomised double-blind crossover trial. Gastrointestinal symptoms, concentrations of PGE2-M in blood and urine, and urinary 6-keto PGF1alpha (as indicators of prostaglandin synthesis), and urinary nitrate and nitrite as well as cyclic GMP excretions (as indicators of nitric oxide formation), were measured.
Ibuprofen increased the first 3-h symptom scores (flatulence + borborygmi + abdominal bloating + pain) caused by lactose (P=0.008) but not sucrose. The concentrations of PGE2-M in the plasma and in the urine were unaffected. Lactose increased the urinary excretion of 6-keto PGF1alpha by about 30% (P=0.17), which was inhibited by ibuprofen (P=0.02). The production of nitric oxide was unaffected by lactose or ibuprofen.
The inhibition of prostaglandin synthesis intensified gastrointestinal symptoms in lactose maldigesters, suggesting a negligible role for prostanoids in lactose-induced symptoms.
乳糖耐量试验期间的临床症状类似于治疗性给予前列腺素后出现的症状，且与炎症过程相似。
研究乳糖诱导的胃肠道症状与前列腺素和/或一氧化氮相关的可能性。
在一项随机双盲交叉试验中，9名消化功能不良者在禁食过夜后，摄入含或不含前列腺素合成抑制剂（布洛芬）的乳糖或蔗糖。测量胃肠道症状、血液和尿液中PGE2-M的浓度、尿6-酮-前列腺素F1α（作为前列腺素合成的指标）、尿硝酸盐和亚硝酸盐以及环磷酸鸟苷排泄量（作为一氧化氮形成的指标）。
布洛芬增加了乳糖引起的最初3小时症状评分（肠胃气胀+肠鸣音+腹胀+疼痛）（P=0.008），但对蔗糖引起的症状评分无影响。血浆和尿液中PGE2-M的浓度未受影响。乳糖使尿6-酮-前列腺素F1α的排泄量增加约30%（P=0.17），布洛芬可抑制这一增加（P=0.02）。一氧化氮的生成不受乳糖或布洛芬的影响。
前列腺素合成的抑制加剧了乳糖消化功能不良者的胃肠道症状，提示类前列腺素在乳糖诱导的症状中作用可忽略不计。
