Esophageal epithelial hyperproliferation following long-term alcohol consumption in rats: effects of age and salivary gland function.
Esophageal epithelial hyperproliferation following long-term alcohol consumption in rats: effects of age and salivary gland function.
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大鼠长期饮酒后食管上皮过度增殖：年龄和唾液腺功能的影响。
DOI：
10.1093/jnci/85.24.2030
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发表时间：
1993
期刊：
影响因子：
--
通讯作者：
H. Seitz
中科院分区：
文献类型：
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作者：
Ulrich A. Simanowski;P. Suter;F. Stickel;H. Maier;R. Waldherr;D. Smith;R. Russell;H. Seitz
长期饮酒是人类食道癌的主要风险因素(1-4)。下列因素可能参与食道癌的发生：酒精和/或乙醛对食道上皮的直接毒性作用(5)；依赖细胞色素P-450IIE1的酒精诱导的酶促进致癌物的激活(6)；营养缺乏，特别是锌(7)、维生素A(8)和核黄素(9)；食道动力的变化(引起胃食道反流并导致细胞损伤)；唾液腺功能改变导致食道粘膜冲洗减少(11、12)。由于上皮再生增加是结肠癌的重要临床危险因素(13)，酒精引起的细胞增殖变化可能调节了食道癌的发生。我们小组(14人)和其他研究人员(75人)已经报道了年龄影响胃肠道上皮细胞的再生行为。本研究观察了长期饮酒对不同年龄段雄性Fischer大鼠食道上皮细胞增殖的影响。我们还测量了正常雄性Wistar大鼠和切除涎腺的大鼠在接受高酒精饮食后的上皮细胞增殖情况。实施涎腺切除术的目的是减少唾液的产生，唾液是细胞增殖的重要调节因素。我们的目的是研究酒精和衰老对食道细胞增殖的影响。在实验1中，90只2月龄、12月龄和22月龄的雄性F344大鼠(每年龄组30只)(印第安纳波利斯的SpragueDawley Co.)被随机配对并单独安置在不锈钢铁丝笼中。这些动物被配对喂食流质饲料。他们被随意喂食，但食物摄入量较高的那只动物每天的摄入量被限制为每对动物中消耗较少食物的配偶的食物摄入量。按照利伯和德卡利的描述，36%的卡路里是以酒精或等卡路里碳水化合物的形式摄入的。饲料的酒精浓度为6.2%(体积/体积)。喂养周期为4周。在实验2中，26只2月龄雄性Wistar大鼠被配对饲喂相同的饲料5个月。26只大鼠中有14只在出生后1周、开始流食前1周行涎腺切除术。麻醉下行双侧涎腺切除术(戊巴比妥钠40 mg/kg体重，腹腔注射)。所有动物研究均由德国海德堡大学动物福利委员会、马萨诸塞州波士顿塔夫茨大学动物福利委员会和马萨诸塞州波士顿新英格兰医学中心医院动物福利委员会批准。我们使用中期停滞技术(17)，通过测定22只酒精喂养的动物和对照组F344动物的食道基底上皮细胞出生率(Kb)来测量食道细胞的增殖。动物每公斤体重腹腔注射0.8 mg长春新碱(1 mg/m L生理盐水)，30分钟后，每隔10-15分钟，在婴儿床麻醉下，通过放血(切断主动脉)处死大鼠。组织样本是
Long-term drinking of alcohol is a major risk factor for esophageal cancer in humans (1-4). The following factors are possibly involved in esophageal carcinogenesis: direct alcohol-and/or acetaldehyde-mediated toxic effects on esophageal epithelium (5); enhanced activation of procarcinogens by alcohol-induced enzymes dependent on cytochrome P-450IIE1 (6); nutritional deficiencies, especially of zinc (7), vitamin A (8), and riboflavin (9); changes in esophageal motility causing gastroesophageal reflux with cell injury (70); and altered salivary gland function resulting in decreased rinsing of the esophageal mucosa (11, 12). Since increased epithelial regeneration is a clinically significant risk factor for colon cancer (13), it is possible that alcoholinduced changes in cell proliferation modulate esophageal carcinogenesis. Our group (14) and other investigators (75) have reported that age influences regenerative behavior in gastrointestinal epithelium. In the present study, we investigated the effect of longterm ingestion of alcohol on esophageal epithelial cell proliferation in different age groups of male Fischer rats. We also measured epithelial cell proliferation in intact male Wistar rats and in rats with sialadenectomy, after the animals had received a highalcohol diet. The purpose of performing sialadenectomy was to reduce saliva production, an important regulatory factor of cell proliferation. Our purpose was to investigate the effects of alcohol and aging on esophageal cell proliferation. In experiment 1, ninety 2-, 12-, and 22-month-old male F344 rats (30 in each age group)(Sprague Dawley Co., Indianapolis, Ind.) were randomly paired and individually housed in stainless-steel wire cages. The animals were pair-fed liquid diets. They were fed ad libitum, but the animal with the higher food intake was restricted daily to the food intake of the partner of each pair that consumed less food. Thirty-six percent of the calories were given either as alcohol or isocaloric carbohydrates as described by Lieber and DeCarli (16). The alcohol concentration of the diet was 6.2%(vol/vol). The feeding period was 4 weeks. In experiment 2, 26 2-month-old male Wistar rats were pair-fed the same diets for 5 months. Sialadenectomy was performed on 14 of the 26 rats I week after arrival and 1 week before the liquid diet feeding procedure was started. Bilateral sialadenectomy was performed under anesthesia (pentobarbital sodium, 40 mg/kg body weight given intraperitoneally). All animal studies were approved by the animal welfare committees of the University of Heidelberg, Federal Republic of Germany (FRG), Tufts University, Boston, Mass., and the New England Medical Center Hospital, Boston, Mass.Using the metaphase arrest technique (17), we measured esophageal cell proliferation by determining the birth rate (KB) of esophageal basal epithelial cells in 22 alcohol-fed and control F344 animals of each age group. Animals were given intraperitoneal injections of 0.8 mg vincristine (I mg/mL saline) per kg of body weight, and, after 30 minutes, pairs of rats were killed by exsanguination (by cutting the aorta), using COT anesthesia at 10-to 15-minute intervals. Tissue samples were