Flasch H, Heinz N
Arzneimittelforschung. 1976;26(6):1213-6.
In cats the concentration of cardio-active glycosides in the heart and brain were investigated with trititum-labelled substances. Steady-state conditions were achieved by repeated i.v. injections of ouabain, digoxin, beta-methyldigoxin, digitoxin, and oleandrin over 5 days. 5 h after the last application glycoside concentrations were measured in plasma, urine, heart, cerebrum and cerebellum. Furthermore the metabolic pattern in these compartments was determined. 1. The glycoside concentration in the heart per g wet weight ranges only from 0.93 (oleandrin) to 1.88% (ouabain) of the daily administered dose per kg. 2. The concentrations in the brain show much higher differences between the diverse glycosides: ouabain with a concentration of 0.02%/g wet weight in the cerebrum shows the lowest and oleandrin with 1.60% the highest value. 3. By calculating the mean relative weights for the hearts (3.9 g/kg) and the brains (11.1 g/kg) 3.7% of the daily administered ouabain activity were found in the whole heart and only 0.18% in the whole brain. In contrast to these data the content of heart and brain after giving the more lipophilic oleandrin was 3.6% and 17.7% (!), respectively. 4. Under steady-state conditions the glycosides ouabain, digoxin, beta-methyldigoxin and digitoxin in heart and brain are mainly unchanged whereas oleandrin is transformed at a higher rate to polar metabolites.
用氚标记的物质研究了猫心脏和大脑中心脏活性糖苷的浓度。通过在5天内反复静脉注射哇巴因、地高辛、β - 甲基地高辛、洋地黄毒苷和夹竹桃苷来达到稳态。在最后一次给药5小时后，测量血浆、尿液、心脏、大脑和小脑的糖苷浓度。此外，还确定了这些部位的代谢模式。1. 每克湿重心脏中的糖苷浓度仅为每千克每日给药剂量的0.93%（夹竹桃苷）至1.88%（哇巴因）。2. 不同糖苷在大脑中的浓度差异更大：大脑中浓度为0.02%/克湿重的哇巴因显示出最低值，而夹竹桃苷浓度为1.60%，显示出最高值。3. 通过计算心脏（3.9克/千克）和大脑（11.1克/千克）的平均相对重量，发现整个心脏中每日给药哇巴因活性的3.7%，而整个大脑中仅为0.18%。与这些数据相反，给予亲脂性更强的夹竹桃苷后，心脏和大脑中的含量分别为3.6%和17.7%（！）。4. 在稳态条件下，心脏和大脑中的糖苷哇巴因、地高辛、β - 甲基地高辛和洋地黄毒苷主要未发生变化，而夹竹桃苷则以更高的速率转化为极性代谢物。
