von der Ohe M R, Camilleri M, Kvols L K, Thomforde G M
Gastroenterology Research Unit, Mayo Clinic, Rochester, MN 55905.
N Engl J Med. 1993 Oct 7;329(15):1073-8. doi: 10.1056/NEJM199310073291503.
The pathophysiology of diarrhea in patients with the carcinoid syndrome is not understood. Possible causes include tumor production of neurohumoral substances, such as serotonin and substance P, which stimulate small-bowel and colonic motility, and intestinal abnormalities, such as lymphangiectasia and bacterial overgrowth. We undertook this study to determine whether carcinoid diarrhea is associated with abnormal motor function in the small intestine and colon. We measured the gastric, small-bowel, and colonic transit of radiolabeled solid residue and estimated the volume of the ascending colon in 16 patients with the carcinoid syndrome and diarrhea and 16 normal subjects. We also measured colonic tone and phasic pressure activity by intracolonic multilumen manometry and with an electronic barostat in seven patients and six normal subjects.
The patients with the carcinoid syndrome had elevated 24-hour urinary excretion of 5-hydroxyindoleacetic acid and elevated fasting plasma serotonin concentrations. Transit times in the small bowel and colon were two times (P < 0.001) and six times (P = 0.001) faster in the patients than in the normal subjects. The volume of the ascending colon was approximately 50 percent smaller in the patients than in the normal subjects (P < 0.001). The patients had normal fasting colonic tone; their mean postprandial colonic tone was markedly increased as compared with the values in the normal subjects (mean increase, 41 percent vs. 24 percent; P = 0.03).
Patients with the carcinoid syndrome who have diarrhea have major alterations in gut motor function that affect both the small intestine and colon.
类癌综合征患者腹泻的病理生理学机制尚不清楚。可能的原因包括肿瘤产生神经体液物质，如血清素和P物质，它们刺激小肠和结肠的蠕动，以及肠道异常，如淋巴管扩张和细菌过度生长。我们进行这项研究以确定类癌性腹泻是否与小肠和结肠的运动功能异常有关。我们测量了16例类癌综合征伴腹泻患者和16例正常受试者放射性标记固体残渣的胃、小肠和结肠转运情况，并估计了升结肠的容积。我们还通过结肠内多腔测压法和电子恒压器测量了7例患者和6例正常受试者的结肠张力和阶段性压力活动。
类癌综合征患者24小时尿5-羟吲哚乙酸排泄量升高，空腹血浆血清素浓度升高。患者的小肠和结肠转运时间分别比正常受试者快两倍（P<0.001）和六倍（P = 0.001）。患者升结肠的容积比正常受试者小约50%（P<0.001）。患者空腹结肠张力正常；与正常受试者相比，他们餐后结肠平均张力明显增加（平均增加41%对24%；P = 0.03）。
患有腹泻的类癌综合征患者肠道运动功能有重大改变，影响小肠和结肠。
