Lippe C, Bellantuono V, Castronuovo G, Ardizzone C
Institute of General Physiology, University of Bari, Italy.
Arch Int Physiol Biochim Biophys. 1994 Nov-Dec;102(6):315-8. doi: 10.3109/13813459409007552.
Dopamine addition to the internal fluid bathing the isolated frog skin results in a strong increase of short circuit current (SCC) across this tissue. The effect is dose-dependent, 10(-4) M being the dose resulting in maximal effect. The measure of transepithelial fluxes of both 22Na+ and 36Cl- across symmetrical parts of skin short-circuited in permanence demonstrates that this effect is due to stimulation of Na+ adsorption and Cl- secretion. The former effect, but not the latter one, is mimicked by both SKF89124A and SKF82525J (D1 and D2 agonists, respectively). Moreover the effect of dopamine on SCC and Na+ net flux is wider than that of its synthetic agonists even when both D1 and D2 agonists were added together. It is suggested that the extraeffect of dopamine on SCC is due to a stimulation of Cl- secretion, probably mediated by dopamine interaction with another receptor.
向浸泡分离的蛙皮的内部溶液中添加多巴胺会导致穿过该组织的短路电流（SCC）大幅增加。这种效应呈剂量依赖性，10(-4) M是产生最大效应的剂量。对永久短路的皮肤对称部分进行的22Na+和36Cl-跨上皮通量的测量表明，这种效应是由于Na+吸附和Cl-分泌受到刺激。SKF89124A和SKF82525J（分别为D1和D2激动剂）均可模拟前者的效应，但不能模拟后者的效应。此外，即使同时添加D1和D2激动剂，多巴胺对SCC和Na+净通量的影响也比其合成激动剂更广泛。有人认为，多巴胺对SCC的额外效应是由于Cl-分泌受到刺激，这可能是由多巴胺与另一种受体的相互作用介导的。
