THE EFFECT OF THE BETA-ADRENERGIC AGONIST CLENBUTEROL ON GROWTH AND PROTEIN-METABOLISM IN RAT MUSCLE-CELL CULTURES
THE EFFECT OF THE BETA-ADRENERGIC AGONIST CLENBUTEROL ON GROWTH AND PROTEIN-METABOLISM IN RAT MUSCLE-CELL CULTURES
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DOI：
10.2527/1992.70103014x
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发表时间：
1992-10-01
影响因子：
3.3
通讯作者：
MALTIN, CA
中科院分区：
文献类型：
--
作者：
MCMILLAN, DN;NOBLE, BS;MALTIN, CA
建立新生大鼠肌肉细胞、卫星细胞和L6成肌细胞的培养体系，并测定发育过程中蛋白质代谢的变化。对于所有三种类型的细胞，培养蛋白含量都随着肌管含量的增加而增加。β-肾上腺素能激动剂克伦特罗[添加到10(-7)M的最终浓度]显著刺激了新生儿肌肉培养的融合[如肌酸激酶活性所示]，并增加了培养蛋白的含量。这与给药后24小时内蛋白质合成的分数[ks，百分比/天，+13%，P<；0.05]和绝对[As，微克/天，+19%，P<；0.05]率刺激有关。48h时，AS较对照组增加42%[P<；.01]。相比之下，在卫星细胞培养中，克伦特罗对蛋白质增加、肌酸激酶活性或蛋白质合成没有一致的影响[Ks和As]。同样，该药物对L6成肌细胞或L6肌管培养中的蛋白质合成和蛋白质增加没有刺激作用[在新生儿来源的成纤维细胞培养中也没有影响]。结论：克伦特罗的融合反应以及蛋白质代谢和蛋白质积累的变化在很大程度上依赖于肌肉细胞的起源和遗传完整性。
Cultures were established from neonatal rat muscle cells, satellite cells, and L6 myoblasts and changes in protein metabolism were determined as development proceeded. For all three cell types, culture protein content increased with increasing myotube content. The beta-adrenergic agonist clenbuterol [added to a final concentration of 10(-7) M] significantly stimulated fusion [as indicated by creatine kinase activity] in neonatal muscle cultures and also increased culture protein content. This was associated with a stimulation in both the fractional [ks, percentage/day, +13%, P < .05] and absolute [As, micrograms/day, +19%, P < .05] rates of protein synthesis within 24 h after drug administration. At 48 h, As was increased by 42% above that of controls [P < .01]. In contrast, in satellite cell cultures, clenbuterol had no consistent effects on either protein accretion, creatine kinase activity, or protein synthesis [ks and As]. Similarly, the drug had no stimulatory effect on protein synthesis and protein accretion in L6 myoblast or L6 myotube cultures [and no effect in neonatally derived fibroblast cultures]. It is concluded that the fusion response to clenbuterol and, therefore, changes in protein metabolism and protein accretion are greatly dependent on the origin and genetic integrity of muscle cells.