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Exogenous GTP Enhances the Effects of Sodium Nitrite on Cyclic GMP Accumulation, Vascular Smooth Muscle Relaxation and Platelet Aggregation

1991; Wiley; Volume: 68; Issue: 1 Linguagem: Inglês

10.1111/j.1600-0773.1991.tb01209.x

1600-0773

K. Laustiola, Pauli Vuorinen, Ilkka Pörsti, T. Metsä‐Ketelä, Vesa Manninen, Heikki Vapaatalo,

Cardiac Ischemia and Reperfusion

Abstract: Exogenous guanosine triphosphate (GTP) (1‐2 × 10 −4 M) resulted in increased concentrations of cyclic GMP both in endothelium denuded rat mesenteric artery (RMA) and in human ADP‐stimulated platelets. Sodium nitrite (3.3 × 10 −4 M) relaxed precontracted RMA by 34%. When the arteries were preincubated with GTP (2 × 10 −4 M) sodium nitrite administration resulted in a significantly greater relaxation (58%) of the RMA with concomitant 2‐fold increase in cGMP. Sodium nitrite (1 × 10 −4 M) had an inhibitory effect on ADP‐induced platelet aggregation. Preincubation with GTP enhanced significantly the sodium nitrite‐induced inhibition of ADP‐induced platelet aggregation with a simultaneous 5‐fold increase in cGMP. These results indicate that exogenous GTP enhances the sodium nitrite‐induced stimulation of guanylate cyclase and thus enhances the effects of sodium nitrite on arterial smooth muscle and platelets.