Effects of previous carbohydrate supplementation on muscular fatigue: double-blind, randomized, placebo-controlled crossover study

Abstract AIMS The aim of this study was to examine the effects of previous carbohydrate supplementation on high-volume resistance exercise performance METHODS Twenty males physically independent adults aged ≥18 years participated in a double-blind randomized placebo-controlled crossover study. Sixty minutes before the experimental protocol, each participant ingested 0,6 g.kg of body mass-1 of carbohydrate supplementation or placebo. Maximum voluntary isometric contraction tests were performed before and after the dynamic fatigue induction protocol consisting of 10 sets of 8 repetitions of right leg knee extensors at 120º s-1. RESULTS Lower decrement of the isometric peak torque (p<0,001) and of the rate of torque development (p<0,001) was observed in carbohydrate supplementation after the dynamic protocol. Both concentric and eccentric peak torque differed significantly (p<0,001) between carbohydrate supplementation and placebo treatments from the second set, although the slope of the force-repetitions curve was not different between them. Additionally, the carbohydrate supplementation resulted in a lower session rating of perceived exertion (p<0,05). CONCLUSIONS Previous carbohydrate supplementation attenuates muscle fatigue and internal load exercise in a high-volume isokinetic leg protocol

Interleukin-12 response to NCSRS2 immunization of BALB/C mice against Neospora caninum.

The apicomplexan parasite Neospora caninum can cause abortions and is recognized as an important causative agent responsible for economic and reproductive losses in the cattle industry. Humoral immune response was investigated in BALB/c mice by using recombinant NcSRS2 expressed in Escherichia coli as polyhistidine-tagged fusion proteins. NcSRS2 is the major immunodominant tachyzoite surface antigen of N. caninum. Separate groups of female BALB/c mice were infected subcutaneously with (P) PBS, (N) recNcSRS2, (NIL) recNcSRS2 plus interleukin-12 or (NF) recNcSRS2, in Freund?s adjuvant. Serological analysis showed that the antibodies produced by immunization recognized native protein from N. caninum tachyzoites and that, 14 days after the initial immunization, NcSRS2-specific antibodies were present in all sera tested from the groups N, NIL and NF. NcSRS2 with Freud?s adjuvant led to a stronger immune response, as measured by IgG1 and IgG2a levels, than did other formulations (NF > NIL > N > P; p < 0.001), with a Th2 bias. The results corroborate the potential use of recombinant protein NcSRS2 as a vaccine aimed at reducing congenital transmission. Further studies are required to identify new adjuvants capable of improving the induction of Th1 immune response.Na publicação: Renato Andreotti