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Cell Cycle‐Dependent Modulation of Biosynthesis and Stimulus‐Evoked Release of Catecholamines in PC12 Pheochromocytoma Cells
Author(s) -
Koike Tatsuro,
Takashima Akihiko
Publication year - 1986
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1111/j.1471-4159.1986.tb01767.x
Subject(s) - catecholamine , dopamine , endocrinology , medicine , cell cycle , chemistry , biosynthesis , tyrosine hydroxylase , cell , tyrosine , biology , biophysics , microbiology and biotechnology , biochemistry , enzyme
Catecholamine biosynthesis and its stimulusevoked release in PC12 pheochromocytoma cells were studied as a function of cell cycle by means of HPLC with electrochemical detection. We found that 3,4‐dihydroxyphenylethylamine (dopamine) levels in PC12 cells remained constant throughout the period of cell cycle. In contrast, the noradrenaline content was dependent on the cell cycle: it increased during the S + G 2 phase followed by a decrease in the M phase. These results were confirmed further by measuring the activities catalyzing the catecholamine biosynthesis. Thus, activities of tyrosine 3‐monooxygenase and 3,4‐dihydroxyphenylalanine decarboxylase were independent of the cell cycle, whereas both soluble and membrane‐bound dopamine β‐monooxygenase activities were modulated during the cell cycle. On the other hand, release of the catecholamines stimulated with 50 m M KCI increased in the G 1 phase, reached a maximum in the late G 1 , and then gradually decreased in later periods. We also found that carbamylcholine‐induced release of the catecholamines occurred maximally in the early S + G 2 phase followed by a decrease during the M phase. Cell cycle dependence of the catecholamine release was in good agreement with that of 45 Ca 2+ uptake. Thus, this study provides evidence that the catecholamine biosynthesis and its release in PC12 cells are modulated during the period of cell cycle.