Catecholamines in murine bone marrow derived mast cells

Cultured murine bone marrow derived mast cells (BMMC) were found to store h igh levels of dopamine. (3753 +/- 844 pg/10(7) cells) and occasionally prod uce norepinephrine and epinephrine. The catecholamine synthesis inhibitor, alpha -methyl-para-tyrosine, decreased intracellular catecholamine concentr ations, and activation with ionomycin stimulated dopamine release. Neither dopaminergic receptor antagonists nor exogenous dopamine less than or equal to 10 muM affected IL-3-induced cell proliferation. High exogenous dopamin e (20-100 muM) decreased proliferation and increased apoptosis, and the ant i-oxidant ascorbic acid prevented these effects. Increased expression of th e anti-apoptotic factor Bcl-2 or loss of pro-apoptotic Bax expression atten uated dopamine-induced apoptosis, suggesting the apoptosis proceeds through a mitachondrial pathway. (C) 2001 Elsevier Science B.V. All rights reserve d.