Clausen T, Flatman J A
Br J Pharmacol. 1980 Apr;68(4):749-55. doi: 10.1111/j.1476-5381.1980.tb10868.x.
The relative role of beta 1- and beta 2-adrenoceptors in mediating the stimulating effect of adrenaline on active electrogenic Na-K-transport has been assessed in experiments on rat soleus muscles in vitro and in vivo. 2 In the rat isolated soleus muscle, adrenaline (10(-6) M) increases the resting membrane potential (EM) by 5.8 mV and stimulates 22Na-efflux and ouabain-suppressible 42K-uptake by 91 and 94%, respectively. 3 All of these effects are completely blocked by propranolol (10(-5) M), whereas the beta 1-selective adrenoceptor antagonist, metoprolol, was found to be at least 50 times less potent. 4 The beta 2-adrenoceptor agonist, salbutamol, was at least 100 times as potent as H133/22 (a beta 1-selective agonist) in stimulating 22Na-efflux and 42K-influx. 5 In experiments performed under pentobarbitone anaesthesia, the intravenous injection of adrenaline (5 microgram) or salbutamol (0.5 to 50 microgram) led to a rapid and marked increase in the EM of the exposed soleus muscle. This hyperpolarizing effect could not be accounted for by the concomitant, relatively modest change in extracellular K.
在体外和体内大鼠比目鱼肌实验中，已评估β1和β2肾上腺素能受体在介导肾上腺素对活性电生钠钾转运刺激作用中的相对作用。2在大鼠离体比目鱼肌中，肾上腺素（10^(-6) M）使静息膜电位（EM）增加5.8 mV，并分别刺激22Na外流和哇巴因可抑制的42K摄取增加91%和94%。3所有这些作用均被普萘洛尔（10^(-5) M）完全阻断，而β1选择性肾上腺素能受体拮抗剂美托洛尔的效力至少低50倍。4β2肾上腺素能受体激动剂沙丁胺醇在刺激22Na外流和42K内流方面的效力至少是H133/22（一种β1选择性激动剂）的100倍。5在戊巴比妥麻醉下进行的实验中，静脉注射肾上腺素（5微克）或沙丁胺醇（0.5至50微克）导致暴露的比目鱼肌EM迅速且显著增加。这种超极化作用不能用细胞外钾伴随的相对适度变化来解释。
