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

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 inter...