Mühlbachová E, Príborská Z, Príborský J
Physiol Bohemoslov. 1981;30(3):251-8.
The lipid mobilizing effects of corticotropin (ACTH), beta 1-24-corticotropin-tetracosactide (TCA) and isoprenaline (ISO) were studied in parallel experiments in older rabbits (six months, weight 3.5 kg) and rats (age 75-85 days, weight 275 g) in vitro. The results were analysed quantitatively. Compared with the effect in younger rats the lipid mobilizing action of ISO in older animals does not differ. The same applies to the very low ISO lipolytic potency in rabbits. The ACTH intrinsic activity and affinity decrease in aging rabbits, but not in aging rats. At the concentration 1 x 10(-9) mol/l of TCA 35% of its maximum effect is reached in rabbits and almost the maximum in rats. In comparison with the maximum response to ACTH the maximum of TCA is two times higher in rabbits whereas in rats it reaches only 80% of the ACTH maximum. The order of the intrinsic activities is in older rats and rabbits different: ISO much greater than ACTH greater than TCA (1.00:0.81:0.64) in rats and TCA greater than ACTH greater than ISO (1.00:0.53:0.31) in rabbits. The affinity relations TCA greater than ISO greater than ACTH are identical in both species with the ratios of ACTH:ISO:TCA = 1:50:1740 in rats and 1:34:915 in rabbits. TCA exerts the strongest lipolytic potency in rats which is 5.5 times greater than in rabbits. On the contrary the intrinsic activity of TCA in rabbits is the highest. In older rabbits the ACTH adipokinetic intrinsic activity and affinity decrease faster than those in ISO. The species differences especially in relation to ISO also remain preserved in older animals and this applies to the TCA lipolytic effects, which in turn do not seem to change with aging as much as the effects of ACTH. When evaluating the species differences or the sensitivity changes connected with aging in the action of lipolytic drugs, the intrinsic activity and affinity should be considered separately.
在体外对老年兔（6个月，体重3.5千克）和大鼠（75 - 85日龄，体重275克）进行的平行实验中，研究了促肾上腺皮质激素（ACTH）、β1 - 24 - 促肾上腺皮质激素 - 二十四肽促皮质素（TCA）和异丙肾上腺素（ISO）的脂质动员作用。对结果进行了定量分析。与年轻大鼠相比，ISO在老年动物中的脂质动员作用没有差异。这同样适用于ISO在兔中极低的脂解效力。ACTH的内在活性和亲和力在老年兔中降低，但在老年大鼠中未降低。在浓度为1×10⁻⁹摩尔/升的TCA时，兔达到其最大效应的35%，而大鼠几乎达到最大值。与对ACTH的最大反应相比，TCA的最大值在兔中比ACTH高两倍，而在大鼠中仅达到ACTH最大值的80%。老年大鼠和兔的内在活性顺序不同：在大鼠中ISO远大于ACTH大于TCA（1.00:0.81:0.64），而在兔中TCA大于ACTH大于ISO（1.00:0.53:0.31）。两种物种中TCA大于ISO大于ACTH的亲和力关系相同，大鼠中ACTH:ISO:TCA的比例为1:50:1740，兔中为1:34:915。TCA在大鼠中发挥最强的脂解效力，比兔中高5.5倍。相反，TCA在兔中的内在活性最高。在老年兔中，ACTH的脂肪分解内在活性和亲和力比ISO下降得更快。物种差异，特别是与ISO相关的差异，在老年动物中也仍然存在，这也适用于TCA的脂解作用，而TCA的脂解作用似乎不像ACTH的作用那样随衰老变化那么大。在评估脂解药物作用中与衰老相关的物种差异或敏感性变化时，应分别考虑内在活性和亲和力。
