L-proline is the main energy source in insect vector stages of most trypanosomatids, including Trypanosoma cruzi epimastigotes. This is the first biochemical description of two active proline transporter systems in T. cruzi. Uptake of this amino acid occurred by a low affinity system B and a high affinity system A. System B consistently appeared more specific than System A when excess competing amino acids were used in transport inhibition assays. Furthermore, the high affinity system is 70% inhibited by L-tryptophan, but the low affinity system is not. Both systems were found to be insensitive to the intracellular proline concentration and D-proline did not inhibit L-proline uptake showing that both systems are stereospecific. Both systems were Na+ and K+ independant but dependant on energy since ATP depletion impairs L-proline uptake. The combined action of carbonyl cyanide p-trifluoromethoxyphenyl hydrazone (FCCP) and oligomycin, and the dependence of activity on pH, further differentiated between the two systems leading to the conclusion that the high affinity system is a H+ gradient-dependant transporter whereas the low affinity system depends directly on ATP.

BackgroundAtypical lateralization of language-related functions has been repeatedly found in individuals with autism spectrum conditions (ASC). Few studies have, however, investigated deviations from typically occurring asymmetry of other lateralized cognitive and behavioural domains. Motor deficits are among the earliest and most prominent symptoms in individuals with ASC and precede core social and communicative symptoms.MethodsHere, we investigate whether motor circuit connectivity is (1) atypically lateralized in children with ASC and (2) whether this relates to core autistic symptoms and motor performance. Participants comprised 44 right-handed high-functioning children with autism (36 males, 8 females) and 80 typically developing control children (58 males, 22 females) matched on age, sex and performance IQ. We examined lateralization of functional motor circuit connectivity based on homotopic seeds derived from peak activations during a finger tapping paradigm. Motor performance was assessed using the Physical and Neurological Examination for Subtle Signs (PANESS).ResultsChildren with ASC showed rightward lateralization in mean motor circuit connectivity compared to typically developing children, and this was associated with poorer performance on all three PANESS measures.ConclusionsOur findings reveal that atypical lateralization in ASC is not restricted to language functions but is also present in circuits subserving motor functions and may underlie motor deficits in children with ASC. Future studies should investigate whether this is an age-invariant finding extending to adolescents and adults and whether these asymmetries relate to atypical lateralization in the language domain.Electronic supplementary materialThe online version of this article (doi:10.1186/s13229-016-0096-6) contains supplementary material, which is available to authorized users.

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The effects of chronic intake of di(2-ethylhexyl)phthalate (DEHP) on the main intermediate glycolytic metabolites in liver and gastrocnemius muscle were investigated in experimental animals. Male Wistar rats (90 -100 g) were fed for 21 days either with a standard chow or the same diet supplemented with 2% (w/w) of DEHP. The DEHP-fed rats had an altered in vivo glucose tolerance associated with abnormal glucose intermediate metabolite contents in liver and skeletal muscle. In these rats, the hepatic content of glucose-6 -phosphate (G-6 -P), fructose-6 -phosphate, pyruvate, lactate, glucose-1 -phosphate and glycogen decreased. At the same time, the G-6 -P content decreased while the pyruvate and lactate levels increased in skeletal muscle. These data, along with the high plasma glucose concentration and the normal lactate blood levels of this group, could indicate that DEHP-fed rats could present a deficiency in muscle glucose and lactate transport, a reduction of the flux through muscle hexokinase and hepatic glucokinase, and a reduction in glycogen synthesis.

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