Identification of guanidino succinate as a putative endogenous source of the endothelium derived relaxing factor.
Using a specific HPLC analysis for guanidines, we find that rat aorta contains guanidino succinate (GS), guanidino acetate (GA), guanidino propionate (GP), guanidino butyrate (GB), methyl guanidine (MG) and guanidine. The concentration of L-arginine (0.05 nmol/mg tissue) is significantly lower than the other guanidines. GS is found to be the most potent vasodilator-guanidine in the rat aorta preparation and this vasodilation depends predominantly on the presence of the endothelium. This effect of GS is antagonized by NG-monomethyl L-arginine (L-NMMA), NW-nitro L-arginine benzyl ester (L-NABA), hemoglobin and by methylene blue, all of which are known to block or attenuate endothelium dependent relaxation. Further, the relaxation mediated by GS is accompanied by the formation of cGMP in the rat aorta. From these results we suggest that GS may be a major endogenous source of EDRF.
Thomas
G
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Department of Physiology and Biophysics, Georgetown University Medical Center, Washington, D.C. 20007.
Ramwell
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PW
D000818:Animals; D001011:Aorta / Q000737:chemistry / Q000378:metabolism*; D001120:Arginine / Q000032:analysis; D006152:Cyclic GMP / Q000378:metabolism; D004730:Endothelium, Vascular / Q000378:metabolism*; D005998:Glycine / Q000031:analogs & derivatives / Q000032:analysis / Q000494:pharmacology; D006146:Guanidines / Q000032:analysis / Q000378:metabolism* / Q000494:pharmacology*; D009126:Muscle Relaxation / Q000187:drug effects; D009569:Nitric Oxide / Q000096:biosynthesis*; D011422:Propionates / Q000032:analysis / Q000494:pharmacology; D051381:Rats; D013386:Succinates / Q000032:analysis / Q000378:metabolism* / Q000494:pharmacology
D006146:Guanidines; D011422:Propionates; D013386:Succinates; D009569:Nitric Oxide; C001318:guanidinosuccinic acid; D001120:Arginine; C004946:glycocyamine; D006152:Cyclic GMP; D005998:Glycine; C005775:guanidinopropionic acid