Expression of nitric oxide synthases in rat adrenal zona fasciculata cells.
Nitric oxide (NO) synthase (NOS) expression was analyzed in rat adrenal zona fasciculata. Both neuronal NOS and endothelial NOS mRNAs were detected by RT-PCR, immunohistochemistry, and immunoblot analysis. The biochemical characterization of adrenal zona fasciculata NOS enzymatic activity confirmed the presence of a constitutive isoform. In a cell line derived from mouse adrenal cortex, only endothelial NOS expression was detected by both RT-PCR and immunoblot analysis. Nitrate plus nitrite levels in Y1 cell incubation medium were increased in the presence of L-arginine and the calcium ionophore A23187, but not D-arginine, indicating enzymatic activity. Moreover, a low, but significant, conversion of Larginine to L-citrulline, abolished by the NOS inhibitor, N(G)-nitro-L-arginine, was detected in Y1 cells. The effect of L-arginine on pregnenolone production was examined. L-Arginine decreased both basal and ACTH-stimulated pregnenolone production in Y1 cells. The inhibitory effect of L-arginine could be attributed to endogenously generated NO, because it was blocked by N(G)-nitro-L-arginine, and it was mimicked by the addition of a NO donor, diethylenetriamine-NO. An inhibitory effect of NO on pregnenolone production from 22Rhydroxycholesterol and on steroidogenic acute regulatory protein expression was also determined. Taken together, these results suggest that at least part of the adrenal NO could derive from steroidogenic cells and modulate their function.
Cymeryng
Cora B
CB
Departamento de Bioquímica Humana, Facultad de Medicina, Universidad de Buenos Aires, Paraguay 2155 5th (C1121ABG), Buenos Aires, Argentina. cymeryng@fmed.uba.ar
Lotito
Sebastián P
SP
Colonna
Cecilia
C
Finkielstein
Carla
C
Pomeraniec
Yael
Y
Grión
Natalia
N
Gadda
Luciana
L
Maloberti
Paula
P
Podestá
Ernesto J
EJ
D000306:Adrenal Cortex Neoplasms / Q000201:enzymology; D000818:Animals; D015152:Blotting, Northern; D002478:Cells, Cultured; D005455:Fluorescent Antibody Technique; D015151:Immunoblotting; D007150:Immunohistochemistry; D007527:Isoenzymes / Q000096:biosynthesis; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors / Q000096:biosynthesis* / Q000235:genetics; D052248:Nitric Oxide Synthase Type I; D052250:Nitric Oxide Synthase Type III; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D051381:Rats; D017208:Rats, Wistar; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014158:Transcription, Genetic; D014407:Tumor Cells, Cultured; D015383:Zona Fasciculata / Q000166:cytology / Q000201:enzymology*
D007527:Isoenzymes; D012333:RNA, Messenger; D019001:Nitric Oxide Synthase; D052248:Nitric Oxide Synthase Type I; D052250:Nitric Oxide Synthase Type III; C496322:Nos1 protein, rat; C496316:Nos3 protein, rat