Reference

Electrogenic arginine transport mediates stimulus-secretion coupling in mouse pancreatic b-cells

Electrogenic arginine transport mediates stimulus-secretion coupling in mouse pancreatic b-cells. Smith, Paul A.; Sakura, Hiroshi; Coles, Barbara; Gummerson, Nigel; Proks, Peter; Ashcroft, Frances M. (University Laboratory of Physiology, Oxford OX1 3PT, UK). Journal of Physiology (Cambridge, United Kingdom), 499(3), 625-635 (English) 1997 Cambridge University Press. CODEN: JPHYA7. ISSN: 0022-3751. DOCUMENT TYPE: Journal CA Section: 13 (Mammalian Biochemistry) 1. We have investigated the mechanism by which L-arginine stimulates membrane depolarization, an increase of intracellular calcium ([Ca2+]i) and insulin secretion in pancreatic b-cells. 2. L-Arginine failed to affect b-cell metab., as monitored by NAD(P)H autofluorescence. 3. L-Arginine produced a dose-dependent increase in [Ca2+]i, which was dependent on membrane depolarization and extracellular calcium. 4. The cationic amino acids L-ornithine, L-lysine, L-homoarginine (which is not metabolized) and NG-monomethyl-L-arginine (L-NMMA, a nitric oxide synthase inhibitor) produced [Ca2+]i responses similar to that produced by L-arginine. The neutral nitric oxide synthase inhibitors NG-nitro-L-arginine (L-NNA) and Nw-monomethyl-L-arginine (L-NAME) also increased [Ca2+]i. D-Arginine was ineffective. 5. L-Arginine did not affect whole-cell Ca2+ currents or ATP-sensitive K+ currents, but produced an inward current that was carried by the amino acid. 6. The reverse transcriptase-polymerase chain reaction demonstrated the presence of mRNA for the murine cationic amino acid transporters mCAT2A and mCAT2B within the b-cell. 7. L-Arginine did not affect b-cell exocytosis as assayed by changes in cell capacitance. 8. Our data suggest that L-arginine elevates [Ca2+]i and stimulates insulin secretion as a consequence of its electrogenic transport into the b-cell. This uptake is mediated by the mCAT2A transporter.

Method for the preparation of D-arginine and L-ornithine

Method for the preparation of D-arginine and L-ornithine. Makryaleas, Kyriakos; Drauz, Karlheinz; Bommarius, Andreas ( Degussa Aktiengesellschaft, Germany). U.S. US 5591613 A 7 Jan 1997, 14 pp., Cont.-in-part of U.S. 5,405,761. (English). (United States of America). CODEN: USXXAM. 185423-60-3 is the cas registry number of certain chemical which is used as reagents here. CLASS: ICM: C12P013-10. NCL: 435114000. APPLICATION: US 1994-366544 29 Dec 1994. PRIORITY: DE 1990-4020980 2 Jul 1990; US 1991-715963 17 Jun 1991. DOCUMENT TYPE: Patent CA Section: 16 (Fermentation and Bioindustrial Chemistry) D-Arginine and L-ornithine are prepd. by means of the enzymic conversion of DL-arginine in the presence of an L-arginase which selectively converts L-arginine to L-ornithine, permitting recovery of both D-arginine and L-ornithine. .