L-Arginine inhibits vasopressin-stimulated mesangial cell Ca2+.
L-Arginine (L-Arg) affects various parameters that modulate the progression of renal disease. These same factors [e.g., glomerular filtration rate, changes in mesangial cell (MC) tension, and production of NO] are all controlled at least in part by changes in MC intracellular Ca2+ concentration ([Ca2+]i). We therefore evaluated the effect of L-Arg on MC [Ca2+]i. We found that L-Arg inhibits the vasopressin-stimulated rise in MC [Ca2+]i both in rat and murine cell cultures. This effect does not appear to be due to metabolism of L-Arg to either NO or L-ornithine (L-Orn). Blocking the metabolism of L-Arg with Nomega-monomethyl-L-arginine, an NO synthase inhibitor, or with 20 mM L-valine (L-Val), an inhibitor of Orn formation, does not reverse the inhibition. However, other cationic amino acids, as well guanidine, the functional group of L-Arg, all inhibit the vasopressin-stimulated rise in [Ca2+]i, consistent with a structural basis for this effect. We conclude that 1) L-Arg inhibits vasopressin-stimulated murine and rat MC [Ca2+]i rise, 2) this inhibition is not mediated by metabolism of L-Arg to either NO or L-Orn, and 3) the effect of L-Arg is due to its cationic functional group, guanidine.
Balsam
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L
Division of Nephrology, Department of Medicine, Nassau County Medical Center, East Meadow, NY 11554, USA.
Nikbakht
N
N
D000818:Animals; D001120:Arginine / Q000494:pharmacology*; D001127:Arginine Vasopressin / Q000494:pharmacology* / Q000502:physiology; D002118:Calcium / Q000378:metabolism*; D002461:Cell Line, Transformed; D002478:Cells, Cultured; D005920:Glomerular Mesangium / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D019791:Guanidine / Q000494:pharmacology; D051379:Mice; D051381:Rats; D017207:Rats, Sprague-Dawley; D013095:Spermidine / Q000494:pharmacology; D013096:Spermine / Q000494:pharmacology; D019323:omega-N-Methylarginine / Q000494:pharmacology
D001127:Arginine Vasopressin; D019323:omega-N-Methylarginine; D013096:Spermine; D001120:Arginine; D019791:Guanidine; D002118:Calcium; D013095:Spermidine