Inadequade nutritional environment is associated with increased oxidative stress and insuline resistance which can predispose to cardiovascular diseases. Recent study suggests an increased of L-arginine-nitric oxide (NO) pathway in leukocytes in an animal model of undernutrition1,2. The objective of this study is to investigate the modulation of L-arginine-nitric oxide pathway in platelets in undernutrition during early lactation. Total L-arginine transport and nitric oxide synthase (NOS) activity were investigated in platelets from adult rats, offspring of dams fed with either protein free diet (UN group) or 22% protein diet (C group). The weight was significantly reduced in UN group compared to C group (232 ± 12 vs 303 ± 14). There was no significant difference in serum albumin between two groups (2.9 ± 0.06 vs 3.1 ± 0.11). The transport of L-arginine (pmoles/109 cells/min) is decreased in UN group (3.31 ± 0.42, n = 8) compared to C group (5.68 ± 1.2, n =8, p<0.05). Basal NOS activity, measured by the conversion of L-[3H] arginine to L-[3H] citrulline, was also inhibited in platelets from undernourished rats (0.09 ± 0.02 pmol/108cells, n = 8) compared to controls (0.2 ± 0.03 pmol/108cells, n = 8, p<0.05). Our findings provide the first evidence that L-arginine transport into platelets is inhibited in undernourished rats, associated with a decreased of NO synthesis. Future studies are necessary to determine the exact role of impaired L-arginine NO pathway in platelets in this nutritional condition.
King's College London (2005) J Physiol 565P, PC150
Communications: Impaired L-arginine – NO pathway in platelets from undernourished rats
Moss, MB ; Brunini, TMC ; Demezio da Silva, C ; Silva, SV ; Garcia-Souza, EPE ; de Freitas, MS ; Mourao, TAT ; Leon, DN ; Barja-Fidalgo, C ; Ellory, JC ; Mann, GE ; Mendes Ribeiro, AC ;
1. Departamento de Farmacologia e Psicobiologia, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, Brazil. 2. Departamento de Farmacologia, UNIRIO, Rio de Janeiro, Brazil. 3. Centre for Cardiovascular Biology and Medicine, King's College London, London, United Kingdom. 4. Physiology Department, University of Oxford, Oxford, United Kingdom.
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