Superoxide retards the inactivation of voltage-gated Na + currents

Abstract

Children with cerebral palsy have feeding difficulties that can contribute to undernutrition. The aim of this study was to investigate the effect of early undernutrition on locomotor activity and the expression of the myofibrillar protein MuRF-1 in an experimental model of cerebral palsy (CP). In order to achieve this aim, pregnant rats were divided into two groups according to the diet provided: Normal Protein (NP, n = 9) and Low Protein (LP, n = 12) groups. After birth, the pups were divided into four groups: Normal Protein Sham (NPS, n = 16), Normal Protein Cerebral Palsy (NPCP, n = 21), Low Protein Sham (LPS, n = 20) and Low Protein Cerebral Palsy (LPCP, n = 18) groups. The experimental cerebral palsy protocol consisted of two episodes of anoxia at birth and during the first days of life. Each day, nitrogen flow was used (9l/min during 12 min). After nitrogen exposure, sensorimotor restriction was performed 16 h per day, from the 2nd to the 28th postnatal day (PND). Locomotor activity was evaluated at 8th, 14th, 17th, 21th and 28th PND. At PND 29, soleus muscles were collected to analyse myofibrillar protein MuRF-1. Our results show that CP animals decreased body weight (p < 0.001), which were associated with alterations of various parameters of locomotor activity (p < 0.05), compared to their control. Undernourished animals also showed a decrease (p < 0.05) in body weight and locomotor activity parameters. Moreover, CP decreased MuRF-1 levels in nourished rats (p = 0.015) but not in undernourished rats. In summary, perinatal undernutrition exacerbated the negative effects of cerebral palsy on locomotor activity and muscle atrophy, but it appears not be mediated by changes in MuRF-1 levels.