Young A, Levin R J
Department of Biomedical Science, University of Sheffield.
Exp Physiol. 1991 Nov;76(6):979-82. doi: 10.1113/expphysiol.1991.sp003561.
The effects of the bacterial toxin Escherichia coli STa on electrogenic secretion in proximal, mid and distal rat colon were examined in vitro using the short-circuit current (Isc) as an index of secretion. All areas showed toxin-elevated Isc which was reduced by bumetanide. The proximal colon was the most sensitive (lowest ED50) but displayed the lowest maximal increase in Isc, the mid colon had the largest maximal electrogenic response while the distal colon proved to be the least sensitive (highest ED50). Atropine (1 microM) and tetrodotoxin (1.25 microM) reduced the maximum Isc response to STa by up to 42%, indicating that the enteric nervous system may be partly involved in the response.
利用短路电流（Isc）作为分泌指标，在体外研究了细菌毒素大肠杆菌STa对大鼠近端、中段和远端结肠电分泌的影响。所有部位均显示毒素使Isc升高，而布美他尼可使其降低。近端结肠最敏感（半数有效剂量最低），但Isc的最大增幅最低，中段结肠的最大电反应最大，而远端结肠最不敏感（半数有效剂量最高）。阿托品（1微摩尔）和河豚毒素（1.25微摩尔）使对STa的最大Isc反应降低多达42%，表明肠神经系统可能部分参与了该反应。
