Galactosyl derivatives of L-arginine and D-arginine: synthesis, stability, cell permeation, and nitric oxide production in pituitary GH3 cells.
Nitric oxide (NO) is critical for the normal physiological regulation of the nervous system and other tissues. L-Arginine, but not D-arginine, is the natural substrate for nitric oxide synthase (NOS), for it is enzymatically converted to NO and L-citrulline. However, recent evidence suggests that D-arginine can also produce NO and NO-derivatives via a different pathway. The aim of the present paper was to raise NO levels in the cells by increasing the cell permeation of its precursors. To this aim, two galactosyl prodrugs, L-arginine-D-galactos-6'-yl ester (L-ArgGal) and D-arginine-D-galactos-6'-yl ester (D-ArgGal) were synthesized. Remarkably, using the HPLC-ESI/MS technique, we found that L-ArgGal and D-ArgGal prodrugs both increased the concentration levels of L- and D-arginine and their derivatives in pituitary GH3 cells. Furthermore, we found that D-ArgGal (1) penetrated cell membranes more rapidly than its precursor D-arginine, (2) released arginine more slowly and in greater amounts than L-ArgGal, and (3) produced much higher levels of DAF-2 monitored NO and nitrite than did L-ArgGal under the same experimental conditions. In conclusion, these results indicate that an increase in the cell permeation of L- and D-arginine by L-ArgGal and D-ArgGal can lead to an increase in NO levels.
Melisi
Daniela
D
Division of Pharmacology, Department of Neuroscience, School of Medicine, Federico II University of Naples, Via Sergio Pansini 5, 80131 Naples, Italy.
Secondo
Agnese
A
Montoro
Paola
P
Piacente
Sonia
S
Rimoli
Maria Grazia
MG
Minale
Massimiliano
M
de Caprariis
Paolo
P
Annunziato
Lucio
L
D000818:Animals; D001120:Arginine / Q000031:analogs & derivatives* / Q000138:chemical synthesis* / Q000494:pharmacology; D002417:Cattle; D045744:Cell Line, Tumor; D002463:Cell Membrane Permeability; D002478:Cells, Cultured; D002851:Chromatography, High Pressure Liquid; D042783:Endothelial Cells / Q000187:drug effects / Q000378:metabolism; D004730:Endothelium, Vascular / Q000166:cytology; D005690:Galactose / Q000031:analogs & derivatives* / Q000138:chemical synthesis* / Q000494:pharmacology; D009569:Nitric Oxide / Q000096:biosynthesis*; D009573:Nitrites / Q000378:metabolism; D010902:Pituitary Gland / Q000166:cytology; D011355:Prodrugs / Q000138:chemical synthesis* / Q000494:pharmacology; D051381:Rats; D021241:Spectrometry, Mass, Electrospray Ionization; D013237:Stereoisomerism; D013329:Structure-Activity Relationship
D009573:Nitrites; D011355:Prodrugs; C513363:arginine galactos-6'-yl ester; D009569:Nitric Oxide; D001120:Arginine; D005690:Galactose