A common enzyme may be responsible for the conversion of organic nitrates to nitric oxide in vascular microsomes.
We compared the nitric oxide (NO)-generating behavior of nitroglycerin (NTG), pentaerythritol trinitrate (PEtriN) and isosorbide dinitrate (ISDN), in the microsomal preparation of bovine coronary artery smooth muscle cells. The comparative NO generating activities among these nitrates were consistent with their relative reported vasodilating activities. Consistent with our previous observations with NTG, 400 microM bromosulfophthalein did not affect NO generation from PEtriN and ISDN in vascular microsomes while 400 microM 1-chloro-2,4-dinitrobenzene completely inhibited NO generation from these nitrates. Gel filtration chromatography with solubilized microsomes of bovine aortic smooth muscle cells showed the primary activity of NO generation from all three nitrates to be eluted at about 200 kD, consistent with that found with solubilized microsomes from the bovine coronary artery microsomes. These results suggest that organic nitrates may be converted to NO by one common enzyme in vascular microsomes.
Chung
S J
SJ
Department of Pharmaceutics, School of Pharmacy, State University of New York, Buffalo 14260.
Fung
H L
HL
D000594:Amino Acid Oxidoreductases / Q000302:isolation & purification / Q000378:metabolism*; D000818:Animals; D002417:Cattle; D002850:Chromatography, Gel; D003331:Coronary Vessels / Q000201:enzymology; D007700:Kinetics; D008861:Microsomes / Q000201:enzymology*; D009131:Muscle, Smooth, Vascular / Q000201:enzymology*; D009566:Nitrates / Q000378:metabolism*; D009569:Nitric Oxide / Q000378:metabolism*; D019001:Nitric Oxide Synthase; D013379:Substrate Specificity
D009566:Nitrates; D009569:Nitric Oxide; D019001:Nitric Oxide Synthase; D000594:Amino Acid Oxidoreductases