title: Mesangial cells are able to produce catecholamines in vitro.
abstract: Mesangial cells (MC) participate in the control of the glomerular function due to their ability to synthesize hormones and induce cell contraction. Since MC can produce various kinds of hormones, the purpose of the present study was to determine if they are able to synthesize catecholamines. For this evaluation, the levels of norepinephrine, epinephrine, dopamine, and biopterin, the enzymatic cofactor of tyrosine hydroxylase (TH), were analyzed by HPLC in the intracellular compartment and in the medium of primary cultured MC. To identify and locate the enzymes responsible for monoamine synthesis, TH, dopa decarboxylase, and dopamine beta-hydroxylase, Western blotting and immunocytochemistry were employed using monoclonal and polyclonal antibodies. Concentrations of NE = 57 +/- 8, EPI = 82 +/- 10, and DA = 52 +/- 9 pg/mg protein (X +/- SEM) were found in the cell homogenate. The culture medium showed concentrations of NE = 25 +/- 3, EPI = 33 +/- 3, and DA = 62 +/- 15 pg/mg protein. Western blotting analysis and immunocytochemistry evidenced the presence of all enzymes. Moreover, biopterin was also detected in the intracellular compartment and in the medium (0.28 +/- 0.03 and 5.70 +/- 2 nmol/mg cell protein, respectively). Overall, the data indicate that MC have the biosynthetic machinery necessary to produce catecholamines, suggesting that they can act as a paracrine/autocrine hormone system, contributing to the regulation of glomerular hemodynamic and renal microcirculation.
authors.affiliation: Nephrology Division, Department of Medicine, Federal University of São Paulo/Escola Paulista de Medicina, Brazil. mgm@nefro.epm.br
authors.forename: Giovana Seno
authors.initials: GS
authors.lastname: Di Marco
authors.forename: Maria da Graça
authors.initials: Mda G
authors.lastname: Naffah-Mazzacoratti Md
authors.forename: Carlos P
authors.initials: CP
authors.lastname: Vio
authors.forename: Oscar Fernando Pavão
authors.initials: OF
authors.lastname: Dos Santos
authors.forename: Nestor
authors.initials: N
authors.lastname: Schor
authors.forename: Dulce Elena
authors.initials: DE
authors.lastname: Casarini
mesh_terms: D000818:Animals; D001708:Biopterins / Q000096:biosynthesis; D002395:Catecholamines / Q000096:biosynthesis*; D002478:Cells, Cultured; D004296:Dopa Decarboxylase / Q000378:metabolism; D004298:Dopamine / Q000096:biosynthesis; D004299:Dopamine beta-Hydroxylase / Q000378:metabolism; D004837:Epinephrine / Q000096:biosynthesis; D005920:Glomerular Mesangium / Q000378:metabolism*; D066298:In Vitro Techniques; D009638:Norepinephrine / Q000096:biosynthesis; D051381:Rats; D014446:Tyrosine 3-Monooxygenase / Q000378:metabolism
chemical_list: D002395:Catecholamines; D001708:Biopterins; D014446:Tyrosine 3-Monooxygenase; D004299:Dopamine beta-Hydroxylase; D004296:Dopa Decarboxylase; D004298:Dopamine; D009638:Norepinephrine; D004837:Epinephrine