M. Jurani et al., ENHANCED ORNITHINE DECARBOXYLASE ACTIVITY OF CHICK MUSCLE-CELLS IN CULTURE BY BETA-ADRENERGIC AGONISTS, Methods and findings in experimental and clinical pharmacology, 18(1), 1996, pp. 13-17
The ability of beta-adrenergic agonists to stimulate ornithine decarbo
xylase activity (ODC) in chick muscle cell culture prepared from 11-da
y old embryos was evaluated. After 72 h of preincubation (myotube form
ation) the medium was supplemented for 4 h with noradrenaline, ritodri
ne, isoproterenol or clenbuterol, at concentrations of 10(-12), 10(-9)
and 10(-6) mol/l. No significant response of ODC activity to noradren
aline was observed. The highest concentration (10(-6) mol/l) of the be
ta-adrenergic agonists ritodrine and isoproterenol elevated the activi
ty of ODC. Clenbuterol was the most active beta-adrenergic agonist. Th
e lowest concentration (10(-12) mol/l) had an apparent effect on ODC a
ctivity in muscle cell culture, and the substitution of media at level
s of 10(-9) and 10(-6) mol/l had a similar effect in comparison to con
trols. The potency of beta-adrenergic agonists in increasing ODC activ
ity was on the following order: noradrenaline, ritodrine, isoprotereno
l, clenbuterol. Results indicate that beta-adrenergic agonists may dir
ectly stimulate ODC activity followed by physiological processes in th
e muscle cells ill the early stage of chick embryonic development.