| Abstract: | The basic mechanisms of regulation of Ca2+ influx in proliferating and differentiating myoblasts, in culture have been studied. The presence of L-type Ca2+ channels in proliferating myoblasts has been shown for the first time. The influx of Ca2+ through these channels was shown to be regulated by the adrenergic system. The influx of Ca2+ through L-type Ca2+ channels after the activation of the adrenergic system by the addition of adrenaline in comparison with the contribution of reticular stocks exhausted by ATP in calcium-free medium was estimated. It was shown that the Ca2+ influx in proliferating myoblasts is regulated by beta-2 adrenergic receptors whose action is mediated by adenylate cyclase through L-type calcium channels. In differentiating myoblasts, the Ca2+ influx on the activation of the adrenergic system was essentially lower than in proliferating cells. It was found that the maximum influx of Ca2+ may be reached by the exhaustion of reticular stocks. |
