Lipid metabolism in rats is modified by nitric oxide avilability through a Ca++-dependent mechanism.

MARRA CARLOS A; NELLA, JULIO; MANTI, DAMIÁN; ALANIZ, MARÍA J. TACCONI DE

LIPIDS

American Oil Chem Soc. Press

Lugar: Philadelphia; Año: 2007 vol. 42 p. 211 - 218

0024-4201

Abstract  We studied lipid metabolism and the antioxidant defense system in plasma and liver of rats fed diets supplemented with Lx-nitro-L-arginine methyl ester (L-NAME), isosorbide dinitrate (DIS), L-arginine (Arg), or the associations of these drugs. Liver hydroperoxide and thiobarbituric-acid-reactive substance (TBARS) levels were decreased by Arg and increased by L-NAME or DIS treatments. Oxidized glutathione and conjugated dienes were increased by DIS. Nitrate + nitrite levels and serum calcium ([Ca++]) were incremented by Arg or DIS and reduced by L-NAME. Superoxide dismutase and catalase activities decreased under Arg treatment, while LNAME or DIS caused stimulation. Liver high-density lipoprotein (HDL) cholesterol was increased by DIS or NAME (alone or associated with Arg). Free fatty acids and neutral and polar lipids were increased by Arg, LNAME, and DIS. However, predominating phospholipid synthesis increased the neutral/polar ratio. Decreased levels of nitric oxide (NO) (low [Ca++]) was directly associated with increased fatty acid synthetase, decreased phospholipase A2, carnitine-palmitoyl transferase, and fatty acid desaturase activities. Raised NO (high [Ca++]) inversely correlated with increased phospholipase-A2 and acyl-coenzyme A (CoA) synthetase and decreased fatty acid synthetase and b-oxidation rate. Arg or DIS produced changes that were partially reverted by association with L-NAME. Based on these observations, prolonged therapeutical approaches using drugs that modify NO availability should be carefully considered.We studied lipid metabolism and the antioxidant defense system in plasma and liver of rats fed diets supplemented with Lx-nitro-L-arginine methyl ester (L-NAME), isosorbide dinitrate (DIS), L-arginine (Arg), or the associations of these drugs. Liver hydroperoxide and thiobarbituric-acid-reactive substance (TBARS) levels were decreased by Arg and increased by L-NAME or DIS treatments. Oxidized glutathione and conjugated dienes were increased by DIS. Nitrate + nitrite levels and serum calcium ([Ca++]) were incremented by Arg or DIS and reduced by L-NAME. Superoxide dismutase and catalase activities decreased under Arg treatment, while LNAME or DIS caused stimulation. Liver high-density lipoprotein (HDL) cholesterol was increased by DIS or NAME (alone or associated with Arg). Free fatty acids and neutral and polar lipids were increased by Arg, LNAME, and DIS. However, predominating phospholipid synthesis increased the neutral/polar ratio. Decreased levels of nitric oxide (NO) (low [Ca++]) was directly associated with increased fatty acid synthetase, decreased phospholipase A2, carnitine-palmitoyl transferase, and fatty acid desaturase activities. Raised NO (high [Ca++]) inversely correlated with increased phospholipase-A2 and acyl-coenzyme A (CoA) synthetase and decreased fatty acid synthetase and b-oxidation rate. Arg or DIS produced changes that were partially reverted by association with L-NAME. Based on these observations, prolonged therapeutical approaches using drugs that modify NO availability should be carefully considered.