Forsyth G W, Hamilton D L, Goertz K E, Johnson M R
Infect Immun. 1978 Aug;21(2):373-80. doi: 10.1128/iai.21.2.373-380.1978.
The effects of cholera toxin on mucosal cyclic nucleotide concentrations and on net fluid secretion in the porcine small intestine are reported. Cholera toxin causes net secretion of fluid into the small intestine of weanling pigs, and secretory rates are dependent on the dose of the toxin placed in intestinal loops. Intestinal secretion due to cholera toxin exposure was not consistently accompanied by elevated concentrations of mucosal cyclic AMP or cyclic GMP. Net fluid fluxes in individual loops did not correlate with mucosal cyclic AMP concentration in the same loop. Jejunal adenylate cyclase was activated to a lesser extent in pigs, compared with rabbits, after in vivo treatment with cholera toxin. In vitro activation in cell-free homogenates was similar for both species. Papaverine was similar to cholera toxin in causing fluid secretion without cyclic AMP accumulations, but 3-isobutyl-1-methyl xanthine significantly increased cyclic AMP concentration and induced fluid secretion in pigs. Weanling pigs appeared to differ from rabbits in having a secretory response to cholera toxin which was independent of elevations in total mucosal cyclic AMP concentration.
本文报道了霍乱毒素对猪小肠黏膜环核苷酸浓度及液体净分泌的影响。霍乱毒素可导致断奶仔猪小肠内液体净分泌，分泌速率取决于置于肠袢中的毒素剂量。霍乱毒素暴露引起的肠道分泌并非始终伴随着黏膜环磷酸腺苷（cAMP）或环磷酸鸟苷（cGMP）浓度的升高。单个肠袢中的液体净通量与同一肠袢中的黏膜cAMP浓度无关。与兔相比，猪经霍乱毒素体内处理后空肠腺苷酸环化酶的激活程度较小。两种动物在无细胞匀浆中的体外激活情况相似。罂粟碱与霍乱毒素相似，可引起液体分泌而无cAMP积累，但3-异丁基-1-甲基黄嘌呤可显著提高猪的cAMP浓度并诱导液体分泌。断奶仔猪对霍乱毒素的分泌反应似乎与兔不同，其与总黏膜cAMP浓度升高无关。
