Department of Pharmaceutics, The School of Pharmacy, University of London, 29/39 Brunswick Square, London, United Kingdom.
Eur J Pharm Sci. 2011 Jan 18;42(1-2):3-10. doi: 10.1016/j.ejps.2010.09.019. Epub 2010 Oct 13.
Laboratory animals are often used in drug delivery and research. However, basic information about their gastrointestinal pH, fluid volume, and lymphoid tissue is not completely known. We have investigated these post-mortem in healthy guinea pigs, rabbits and pigs, to assess their suitability for pre-clinical studies by comparing the results with reported human literature. The mean gastric pH (fed ad libitum) was 2.9 and 4.4 in guinea pig and pig, respectively. In contrast, a very low pH (1.6) was recorded in the rabbits. The small intestinal pH was found in the range of 6.4-7.4 in the guinea pigs and rabbits, whereas lower pH (6.1-6.7) was recorded in the pig, which may have consequences for ionisable or pH responsive systems when tested in pig. A relatively lower pH than in the small intestine was found in the caecum (6.0-6.4) and colon (6.1-6.6) of the guinea pig, rabbit and the pig. The water content in the gastrointestinal tract of guinea pig, rabbit and pig was 51g, 153g and 1546g, respectively. When normalized to the body weight, the guinea pig, had larger amounts of water compared to the rabbit and the pig (guinea pig>rabbit>pig); in contrast, a reverse order was found when normalized to per unit length of the gut (guinea pig<rabbit<pig). The lymphoid tissue distribution (lymphoid follicles, Peyer's patches and long strips) along the length of the gut in these animals is presented; in particular, an abundance of lymphoid tissue was found in pig's stomach, small intestine and caecum, and rabbit's appendix. Their ample presence indicated the potential utility of these animal species in oral and colonic vaccination. These differences in the gastrointestinal parameters of the guinea pig, rabbit and pig reiterates the crucial importance of correctly selecting animal models for pre-clinical studies.
实验动物常用于药物输送和研究。然而，它们的胃肠道 pH 值、液体量和淋巴组织的基本信息并不完全清楚。我们已经对健康的豚鼠、兔子和猪进行了死后调查，以通过将结果与已发表的人类文献进行比较，评估它们在临床前研究中的适用性。在豚鼠和猪中，空腹时的平均胃 pH 值分别为 2.9 和 4.4。相比之下，兔子的 pH 值非常低（1.6）。在豚鼠和兔子中，小肠 pH 值在 6.4-7.4 之间，而在猪中记录到较低的 pH 值（6.1-6.7），当在猪中测试时，这可能会对可电离或 pH 反应性系统产生影响。在豚鼠、兔子和猪的盲肠（6.0-6.4）和结肠（6.1-6.6）中发现 pH 值相对较低。豚鼠、兔子和猪的胃肠道水分含量分别为 51g、153g 和 1546g。当按体重归一化时，豚鼠与兔子和猪相比，水分含量更大（豚鼠>兔子>猪）；相反，当按肠道单位长度归一化时，发现相反的顺序（豚鼠<兔子<猪）。本文介绍了这些动物沿肠道长度的淋巴组织分布（淋巴滤泡、派尔氏斑和长带）；特别是，在猪的胃、小肠和盲肠以及兔子的阑尾中发现了大量的淋巴组织。它们的大量存在表明这些动物物种在口服和结肠疫苗接种中的潜在应用。豚鼠、兔子和猪的胃肠道参数的这些差异再次强调了为临床前研究正确选择动物模型的重要性。
