title: Differential effects of physical exercise and L-arginine on cortical spreading depression in developing rats.
abstract: 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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Departamento de Nutrição, Universidade Federal de Pernambuco, Recife PE, Brazil.
authors.forename: Heloisa Mirelle Costa
authors.initials: HM
authors.lastname: Monteiro
authors.forename: Débora
authors.initials: D
authors.lastname: de Lima e Silva
authors.forename: João Paulo Bernardo Dantas
authors.initials: JP
authors.lastname: de França
authors.forename: Luciana Maria Silva de Seixas
authors.initials: LM
authors.lastname: Maia
authors.forename: Monara Kaélle Cruz
authors.initials: MK
authors.lastname: Angelim
authors.forename: Angela Amâncio
authors.initials: AA
authors.lastname: dos Santos
authors.forename: Rubem Carlos Araújo
authors.initials: RC
authors.lastname: Guedes
mesh_terms: D000375:Aging / Q000502:physiology*; D000818:Animals; D001120:Arginine / Q000008:administration & dosage*; D001835:Body Weight; D001921:Brain / Q000254:growth & development*; D013181:Cortical Spreading Depression / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D006639:Histidine / Q000378:metabolism; D008297:Male; D009043:Motor Activity; D009929:Organ Size; D051381:Rats; D017208:Rats, Wistar
chemical_list: D006639:Histidine; D001120:Arginine