Regional distribution of EDRF/NO-synthesizing enzyme(s) in rat brain.
Stimulation of soluble guanylyl cyclase and increase in cyclic GMP in rat fetal lung fibroblasts (RFL-6 cells) was used as a bioassay to detect EDRF/NO formation. The cytosolic fraction of whole rat brain synthesized an EDRF/NO-like material in a process dependent on L-arginine and NADPH. The enzymatic activity was destroyed by boiling and inhibited by N omega-nitro-L-arginine. Hemoglobin and methylene blue blocked the effect of EDRF/NO. When different brain regions were analyzed in the presence of L-arginine and NADPH, the cytosolic fraction from cerebellum showed the highest EDRF/NO-forming activity (2-3 times higher than whole brain). Activity similar to whole brain was found in hypothalamus and midbrain. Enzymatic activities in striatum, hippocampus and cerebral cortex were about two thirds of whole brain. The lowest activity (less than half of whole brain) was found in the medulla oblongata.
Abbott Laboratories, Abbott Park, Illinois 60064.
U
U
Förstermann
L D
LD
Gorsky
J S
JS
Pollock
H H
HH
Schmidt
M
M
Heller
F
F
Murad
D000594:Amino Acid Oxidoreductases / Q000378:metabolism*; D000818:Animals; D001921:Brain / Q000201:enzymology*; D002531:Cerebellum / Q000378:metabolism; D003600:Cytosol / Q000201:enzymology / Q000378:metabolism; D005347:Fibroblasts; D006157:Guanosine Monophosphate / Q000378:metabolism; D006162:Guanylate Cyclase / Q000378:metabolism; D008168:Lung; D008526:Medulla Oblongata / Q000378:metabolism; D009569:Nitric Oxide / Q000378:metabolism*; D019001:Nitric Oxide Synthase; D051381:Rats
D009569:Nitric Oxide; D006157:Guanosine Monophosphate; D019001:Nitric Oxide Synthase; D000594:Amino Acid Oxidoreductases; D006162:Guanylate Cyclase