Accumulation of endogenous inhibitors for nitric oxide synthesis and decreased content of L-arginine in regenerated endothelial cells.
1. We examined regeneration of endothelial cells (ECs), neointima formation, decreased endothelium-dependent relaxation (EDR) and changes in the contents of L-arginine, NG-monomethyl-L-arginine (L-NMMA), asymmetrical NG, NG-dimethylarginine (ADMA) and symmetrical NG,NG-dimethylarginine (SDMA) in the regenerated ECs, 6 weeks after balloon denudation of the rabbit carotid artery. 2. Regeneration of ECs was completed in 6 weeks and a significant neointima formation accompanied by the decreased EDR was observed. 3. L-NMMA and ADMA contents in the regenerated ECs (23.5 +/- 4.3 and 21.2 +/- 2.0 pmol mg-1 DNA, respectively) were significantly (P < 0.05 and P < 0.01) higher than those in the control ECs (8.8 +/- 3.0 and 7.4 +/- 1.9 pmol mg-1 DNA, respectively), whereas L-arginine was significantly (P < 0.005) decreased in the regenerated ECs (31,470 +/- 1,050 pmol mg-1 DNA) as compared to that in the control ECs (47,870 +/- 1,890 pmol mg-1 DNA). SDMA content was below the assay limits. 4. L-NMMA and ADMA, but not SDMA, inhibited the EDR induced by acetylcholine in a concentration-dependent manner. The inhibition with L-NMMA and ADMA was prevented by an addition of L-arginine, but not by D-arginine. 5. These results suggest that the accumulation of endogenous inhibitors for nitric oxide synthesis and decreased L-arginine content are associated with decreased NO production/release from regenerated ECs and neointima formation.
Azuma
H
H
Department of Medicinal Chemistry, Tokyo Medical and Dental University, Japan.
Sato
J
J
Hamasaki
H
H
Sugimoto
A
A
Isotani
E
E
Obayashi
S
S
D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D001120:Arginine / Q000031:analogs & derivatives / Q000378:metabolism*; D002339:Carotid Arteries / Q000187:drug effects; D002845:Chromatography; D004305:Dose-Response Relationship, Drug; D004727:Endothelium / Q000378:metabolism*; D004791:Enzyme Inhibitors / Q000378:metabolism; D005453:Fluorescence; D008297:Male; D008855:Microscopy, Electron, Scanning; D009569:Nitric Oxide / Q000378:metabolism*; D011817:Rabbits; D019323:omega-N-Methylarginine
D004791:Enzyme Inhibitors; D019323:omega-N-Methylarginine; D009569:Nitric Oxide; D001120:Arginine; D000109:Acetylcholine