Kapral F A
Ciba Found Symp. 1985;112:215-29. doi: 10.1002/9780470720936.ch12.
The classical enterotoxins are known primarily for their ability to cause emesis and diarrhoea in cases of staphylococcal food poisoning but they also exhibit other biological activities. The seven antigenic types of toxin have molecular weights in the range 25 000-35 000. All types induce emesis in man and monkey and are of comparable potency. The enterotoxins seem to induce emesis by stimulating neural receptors in the intestine rather than acting on the medulla directly. The mechanism whereby diarrhoea is produced is unclear. Another product of Staphylococcus aureus which meets the more recent definition of an enterotoxin is the delta toxin. This toxin is an amphipathic peptide having an Mr of 2977 and possessing the ability to interact with a variety of hydrophobic substances. It is cytotoxic, can increase vascular permeability in guinea-pig skin, and can increase cellular cyclic AMP levels in guinea-pig ileum. In the ileum delta toxin also inhibits water absorption, apparently by increasing the bidirectional movement of Na+ and Cl- across the mucosa. This response does not appear to be mediated by cyclic AMP since the changes in ion fluxes precede the increases in cellular cyclic AMP levels. In high doses delta toxin also elicits a positive response in the neonatal mouse after intragastric inoculation.
经典肠毒素主要因其在葡萄球菌食物中毒病例中引起呕吐和腹泻的能力而闻名，但它们也表现出其他生物学活性。七种抗原类型的毒素分子量在25000-35000范围内。所有类型的毒素均可在人和猴中诱发呕吐，且效力相当。肠毒素似乎是通过刺激肠道中的神经受体而非直接作用于延髓来诱发呕吐的。腹泻产生的机制尚不清楚。金黄色葡萄球菌的另一种符合肠毒素最新定义的产物是δ毒素。这种毒素是一种两亲性肽，分子量为2977，能够与多种疏水性物质相互作用。它具有细胞毒性，可增加豚鼠皮肤的血管通透性，并可提高豚鼠回肠中的细胞环磷酸腺苷水平。在回肠中，δ毒素还能抑制水的吸收，显然是通过增加Na+和Cl-在黏膜上的双向移动来实现的。这种反应似乎不是由环磷酸腺苷介导的，因为离子通量的变化先于细胞环磷酸腺苷水平的升高。高剂量的δ毒素在新生小鼠经胃内接种后也会引发阳性反应。
