Changes and role of adrenoceptors in PC12 cells after phenylephrine administration and apoptosis induction

The present study addresses the hypothesis that adrenergic regulation modulates the effect of apoptosis Therefore we studied whether alpha 1-adrenergic receptor s agonist phenylephrine (PE) can affect or induce apoptosis in rat pheochromocytoma (PC12) cells We have shown that PE treatment did not Increase level of the apoptosis or level of the caspase 3 mRNA. When apoptosis was induced in the presence of PE caspase 3 mRNA was significantly increased while the percentage of apoptotic cells remained unchanged compared to apoptotic group without PE During this process alpha 1D- beta 2- and beta 3-adrenergic receptors (ARs) were upregulated Since all these three types of ARs are differently localized in the cell we assume that mutual communication of all three ARs is crucial to participate in this signaling and during development of apoptosis some of these systems might translocate Another Important system in handling noradrenaline during apoptosis might be noradrenaline transporter (NET) since It was downregulated in apoptotic cells treated with PE compared to untreated apoptotic cells However precise mechanism of mutual communication among all these systems remains to be elucidated (C) 2010 Elsevier Ltd All rights reserved