Acetylcholine-induced calcium signalling in adrenaline- and noradrenaline-containing adrenal chromaffin cells

• Published in: Archives of biochemistry and biophysics 2004-04, Vol.424 (1), p.23-32
• Main Authors: Zaika, O.L, Pochynyuk, O.M, Kostyuk, P.G, Yavorskaya, E.N, Lukyanetz, E.A
• Format: Article
• Language: English
• Subjects: Acetylcholine - pharmacology; Acetylcholine receptor; Adrenal Medulla - cytology; Adrenaline; Animals; Atropine - pharmacology; Calcium; Calcium - chemistry; Calcium - metabolism; Calcium Signaling - drug effects; Calcium Signaling - physiology; Cholinergic Agonists - pharmacology; Cholinergic Antagonists - pharmacology; Chromaffin cells; Chromaffin Cells - chemistry; Chromaffin Cells - drug effects; Chromaffin Cells - metabolism; Chromaffin Cells - physiology; Cytophotometry - methods; Epinephrine - metabolism; Histocytochemistry - methods; Ionotropic receptors; Metabotropic receptors; Muscarine - pharmacology; Nicotine - pharmacology; Noradrenaline; Norepinephrine - metabolism; Rats; Receptors, Muscarinic - metabolism; Receptors, Muscarinic - physiology; Receptors, Nicotinic - metabolism; Receptors, Nicotinic - physiology; Tubocurarine - pharmacology
• ISSN: 0003-9861; 1096-0384
• DOI: 10.1016/j.abb.2004.01.012

Adrenal chromaffin cells secrete catecholamines in response to cholinergic receptor activation by acetylcholine (ACh). Characteristics of Ca 2+ transients induced by activation of nicotinic (nAChRs) and muscarinic (mAChRs) receptors were analyzed using Fura-2 fluorescent measurements on rat chromaffin cells. We first found two populations of chromaffin cells, which differently responded on AChR stimulation. In the first group ( n-cells), consecutive ACh applications evoked persistent Ca 2+ transients, whereas desensitizing transients were observed in the other group ( m-cells). The AChR agonists and antagonists precisely imitated or abolished the ACh action on n- and m-type cells, respectively. Cytochemical staining showed that n-cells contained adrenaline, whereas m-cells—noradrenaline. Thus, for the first time we found that nAChRs and mAChRs are differentially expressed in adrenergic and noradrenergic chromaffin cells, respectively. Our data suppose that chromaffin cells can be differentially regulated by incoming ACh signals and in such way release different substances—adrenaline and noradrenaline.