Peterson J W, Molina N C, Houston C W, Fader R C
Toxicon. 1983;21(6):761-75. doi: 10.1016/0041-0101(83)90065-x.
Cholera and salmonellosis are two diarrheal diseases in which intestinal tissue cyclic adenosine monophosphate (cAMP) concentrations are elevated. Investigations of each experimental disease were initiated to identify the specific intestinal cells containing the elevated cAMP. Epithelial cells were eluted from the mucosa of infected and control intestinal loops of adult rabbits, after which the cAMP content of the epithelial cell fractions and the lamina propria cells was extracted and assayed. The identity of the epithelial cells (in the villus tip-to-crypt cell gradient) was monitored by measuring their intracellular alkaline phosphatase activity, while scanning electron microscopy was used to visualize the effects of infection and cell elution techniques. Clearly, in both experimental cholera and salmonellosis, elevated cAMP levels were associated with crypt epithelial cells. Villus tip epithelial cells from either infection tended to contain less cAMP than those of noninfected control tissue. In Salmonella-infected loops, it was apparent that cAMP was also elevated in lamina propria cell fractions. Lamina propria cells from V. cholerae-infected intestinal loops contained only basal levels of cAMP. In vitro exposure of isolated intestinal cells from normal rabbit intestine to a cell-free lysate of Salmonella resulted in elevation of cAMP in the epithelial cells and lamina propria cells. We conclude that in experimental cholera and salmonellosis, significant elevation of the cAMP levels occurred in intestinal crypt cells, consistent with an enterotoxin-mediated mechanism. In Salmonella-infected loops, it was unclear if the increased concentration of cAMP in lamina propria cells was generated by enterotoxin released from the invasive salmonellae or by prostaglandins formed during the inflammatory response to the bacteria, or by both mechanisms.
霍乱和沙门氏菌病是两种腹泻疾病，其肠道组织中环磷酸腺苷（cAMP）浓度会升高。针对每种实验性疾病展开研究，以确定含有升高的cAMP的特定肠道细胞。从成年兔受感染和对照肠袢的黏膜中洗脱上皮细胞，之后提取并测定上皮细胞组分和固有层细胞的cAMP含量。通过测量其细胞内碱性磷酸酶活性来监测上皮细胞（在绒毛顶端至隐窝细胞梯度中）的特性，同时使用扫描电子显微镜观察感染和细胞洗脱技术的效果。显然，在实验性霍乱和沙门氏菌病中，cAMP水平升高均与隐窝上皮细胞有关。来自任一感染的绒毛顶端上皮细胞所含的cAMP往往比未感染对照组织的少。在沙门氏菌感染的肠袢中，固有层细胞组分中的cAMP也明显升高。霍乱弧菌感染的肠袢中的固有层细胞仅含有基础水平的cAMP。将正常兔肠道分离的肠细胞在体外暴露于沙门氏菌的无细胞裂解物中，导致上皮细胞和固有层细胞中的cAMP升高。我们得出结论，在实验性霍乱和沙门氏菌病中，肠道隐窝细胞中cAMP水平显著升高，这与肠毒素介导的机制一致。在沙门氏菌感染的肠袢中，尚不清楚固有层细胞中cAMP浓度的增加是由侵入性沙门氏菌释放的肠毒素引起的，还是由对细菌炎症反应期间形成的前列腺素引起的，或者是由这两种机制共同引起的。
