Differential effects of physical exercise and l-arginine on cortical spreading depression in developing rats

• Published in: Nutritional neuroscience 2011-05, Vol.14 (3), p.112-118
• Main Authors: Monteiro, Heloisa Mirelle Costa, Silva, Débora de Lima e, de França, João Paulo Bernardo Dantas, Maia, Luciana Maria Silva de Seixas, Angelim, Monara Kaélle Cruz, Santos, Ângela Amâncio dos, Guedes, Rubem Carlos Araújo
• Format: Article
• Language: English
• Subjects: Aging - physiology; Animals; Arginine - administration & dosage; Body Weight; Brain - growth & development; Brain development; Cortical spreading depression; Cortical Spreading Depression - drug effects; Developing rat; Dose-Response Relationship, Drug; Histidine - metabolism; l-arginine; Male; Motor Activity; Organ Size; Physical exercise; Rats; Rats, Wistar
• ISSN: 1028-415X; 1476-8305
• DOI: 10.1179/1476830511Y.0000000008

Objective We investigated the effect of early-in-life administration of l-arginine, combined with physical exercise, on cortical spreading depression (CSD) in young and adult rats. Methods l-arginine (300 mg/kg/day, n = 40) or distilled water (vehicle, n = 40) was given to the rats during postnatal days 7-35 by gavage. Physical exercise (treadmill) was carried out during postnatal days 15-35 in half of the animals in each gavage condition described above. The other half (non-exercised) was used for comparison. When the animals reached 35-45 days (young groups) or 90-120 days of age (adult) CSD was recorded on two cortical points during 4 hours and CSD propagation velocity was calculated. Results l-arginine-treated + exercised rats had increased body weight, but not brain weight, in adult age compared to l-arginine + non-exercised ones (P < 0.05). In both young and adult animals, l-arginine increased, whereas exercise decreased the CSD propagation velocity. Analysis of variance revealed a significant interaction between gavage treatment and age (P < 0.001), and also between gavage treatment and exercise (P = 0.004), but not between age and exercise. An additional control group of young rats, treated with 300 mg/kg of l-histidine, presented CSD velocities comparable to the corresponding water-treated controls, suggesting that the CSD acceleration seen in the l-arginine group was an l-arginine-specific effect, rather than an effect due to a non-specific amino acid imbalance. Discussion l-arginine and exercise affect CSD differentially (l-arginine accelerated, while exercise decelerated CSD), and both effects did interact. Probably, they depend on developmental plasticity changes associated with the treatments.