Nassar B A, Manku M S, Reed J D, Tynan M, Horrobin D F
Br Med J. 1974 Apr 6;2(5909):27-9. doi: 10.1136/bmj.2.5909.27.
Rat hearts with coronary circulations perfused by the Langendorff technique were studied. Recordings were made of the electrical and mechanical activity. Once the rate and rhythm of each heart and stabilized it was perfused with Ringer-Locke solution for 90 minutes; frusemide (40 mug/ml) was added to the perfusate during the last 30 minutes of this period. Eighteen experiments were performed-six controls, six in which prolactin at a concentration of 50 ng/ml was added to the perfusate for the whole 90 minutes, and six in which a prolactin concentration of 200 ng/ml was used.With the controls heart rate and rhythm remained steady, but there was a slow decline in amplitude of the contraction. With a prolactin concentration of 50 ng/ml the heart rate rose to about 40% above control during the first hour and after an initial sharp increase the contraction amplitude declined more rapidly than in the controls. The prolactin concentration of 200 ng/ml produced a decline of about 25% in heart rate over the first hour and amplitude behaved much as in the controls. Frusemide had no clear effect on the rate of beating of the controls, but it tended to reverse both the acceleration produced by 50 ng/ml prolactin and the slowing produced by the higher dose. Both the doses of prolactin consistently caused disturbances of rhythm. These effects occur at concentration of prolactin found in human plasma in various pathophysiological conditions.
采用Langendorff技术对具有冠状动脉循环的大鼠心脏进行了研究。记录了其电活动和机械活动。在每颗心脏的心率和节律稳定后，用林格氏乳酸钠溶液灌注90分钟；在此期间的最后30分钟，向灌注液中加入速尿（40微克/毫升）。进行了18项实验——6项为对照实验，6项在整个90分钟内将浓度为50纳克/毫升的催乳素加入灌注液中，6项使用浓度为200纳克/毫升的催乳素。在对照实验中，心率和节律保持稳定，但收缩幅度缓慢下降。当催乳素浓度为50纳克/毫升时，在第一个小时内心率上升至比对照高出约40%，在最初的急剧上升后，收缩幅度的下降比对照实验中更快。200纳克/毫升的催乳素浓度在第一个小时内使心率下降约25%，收缩幅度的变化与对照实验中的情况大致相同。速尿对对照实验中的心跳速率没有明显影响，但它倾向于逆转50纳克/毫升催乳素引起的心率加速以及高剂量催乳素引起的心率减慢。两种剂量的催乳素均持续导致节律紊乱。这些效应在各种病理生理条件下人体血浆中发现的催乳素浓度下都会出现。
