1,721,226 research outputs found
An update on carnosine and anserine research
No full textCarnosine belongs to a family of histidyl dipeptides, consisting of l-histidine and beta-alanine. It is more prevalent in the mammalian and human tissues, whereas its analogues such as anserine, which is methylated at the Nπ of imidazole, is present in birds and fish and balenine, methylated at the Nτ of histidine, is largely present in marine mammals and reptiles (Boldyrev et al. 2013). Despite their early discovery and their prominent concentrations in certain tissues, the exact role and potential of these dipeptides are still not fully understood. Carnosine is a multifunctional dipeptide. Based on its biochemical properties, it has been suggested to be involved in acid–base balance, antioxidant defense and scavenging of lipid peroxidation products. The latter functions of the dipeptide have generated various expectations as therapeutic interventions, e.g. for the pathologies associated with enhanced generation of lipid peroxidation products.
There is a growing interest from the broad scientific community to unravel the fundamental properties as well as the potential application spectrum of carnosine and related dipeptides. As to date (December 2018), over 3300 publications are found on Web of Science when searching for ‘carnosine’, and Fig. 1 displays the fundamental (panel A) and applied research areas (panel B) in which these papers are mostly situated. The majority of fundamental research is performed in the field of biochemistry/molecular biology, pharmacology and physiology (Fig. 1a). The major application fields are neurology, diabetes, cardiovascular disease and nutrition (Fig. 1b), although the interest and relevance are broad and extends all the way to agriculture, zoology, sports sciences, etc. The wide variety of disciplines of the manuscripts in this current Special Issue is a reflection hereof.No Full Tex
The influence of sex, age and heritability on human skeletal muscle carnosine content
No full textThe dipeptide carnosine is found in high concentrations in human skeletal muscle and shows large interindividual differences. Sex and age are determining factors, however, systematic studies investigating the sex effects on muscle carnosine content throughout the human lifespan are lacking. Despite the large inter-individual variation, the intra-individual variation is limited. The question may be asked whether the carnosine content is a muscle characteristic which may be largely genetically determined. A total of 263 healthy male and female subjects of 9–83 years were divided into five different age groups: prepubertal children (PC), adolescents (A), young adults (YA), middle adults (MA) and elderly (E). We included 25 monozygotic and 22 dizygotic twin pairs among the entire study population to study the heritability. The carnosine content was measured non-invasively in the gastrocnemius medialis and soleus by proton magnetic resonance spectroscopy (1H-MRS). In boys, carnosine content was significantly higher (gastrocnemius 22.9%; soleus 44.6%) in A compared to PC, while it did not differ in girls. A decrease
(*16%) was observed both in males and females from YA to MA. However, elderly did not have lower carnosine levels in comparison with MA. Higher correlations were found in monozygotic (r = 0.86) compared to dizygotic (r = 0.51) twins, in soleus muscle, but not in gastrocnemius. In conclusion, this study found an effect of puberty on muscle carnosine content in males, but not in females. Muscle carnosine decreased mainly during early adulthood and hardly from adulthood to elderly. High intra-twin correlations were observed, but muscle-dependent differences preclude clear conclusions toward heritability
Reduced muscle carnosine content in type 2, but not in type 1
No full textCarnosine is present in high concentrations in skeletal muscle where it contributes to acid buffering and functions also as a natural protector against oxidative and carbonyl stress. Animal studies have shown an anti-diabetic effect of carnosine supplementation. High carnosinase activity, the carnosine degrading enzyme in serum, is a risk factor for diabetic complications in humans. The aim of the present study was to compare the muscle carnosine concentration in diabetic subjects to the level in non-diabetics. Type 1 and 2 diabetic patients and matched healthy controls (total n = 58) were included in the study. Muscle carnosine content was evaluated by proton magnetic resonance spectroscopy (3 Tesla) in soleus and gastrocnemius. Significantly lower carnosine content (-45%) in gastrocnemius muscle, but not in soleus, was shown in type 2 diabetic patients compared with controls. No differences were observed in type 1 diabetic patients. Type II diabetic patients display a reduced muscular carnosine content. A reduction in muscle carnosine concentration may be partially associated with defective mechanisms against oxidative, glycative and carbonyl stress in muscle
Personalized Sport and Exercise Nutrition
No full textThis eBook is a collection of articles from a Frontiers Research Topic. Frontiers Research Topics are very popular trademarks of the Frontiers Journals Series: they are collections of at least ten articles, all centered on a particular subject. With their unique mix of varied contributions from Original Research to Review Articles, Frontiers Research Topics unify the most influential researchers, the latest key findings and historical advances in a hot research area! Find out more on how to host your own Frontiers Research Topic or contribute to one as an author by contacting the Frontiers Editorial Office: frontiersin.org/about/contac
Personalized Sport and Exercise Nutrition
No full textThis eBook is a collection of articles from a Frontiers Research Topic. Frontiers Research Topics are very popular trademarks of the Frontiers Journals Series: they are collections of at least ten articles, all centered on a particular subject. With their unique mix of varied contributions from Original Research to Review Articles, Frontiers Research Topics unify the most influential researchers, the latest key findings and historical advances in a hot research area! Find out more on how to host your own Frontiers Research Topic or contribute to one as an author by contacting the Frontiers Editorial Office: frontiersin.org/about/contac
Effect of beta-alanine supplementation on histidine-containing dipeptides in persons with COPD
No full textGross motor coordination in relation to weight status and age in 5- to 12-year-old boys and girls : a cross-sectional study
No full textINTRODUCTION: Motor skill competence is a prerequisite for everyday activities in children and an important aspect underlying their engagement in physical activities. Given the reciprocal relationship between motor competence, or lack thereof, and physical (in)activity, great attention should be paid to skill and coordination level of children with an excessive body mass. The purpose of this cross-sectional study was to investigate gross motor coordination in normal-weight, overweight and obese children across developmental time.
METHODS: Data were collected in 954 Flemish primary school children (500 girls, 454 boys), stratified in consecutive age groups (5-7y, 8-9y, 10-12y). Participants’ weight status (normal-weight, overweight, obese) was defined according to international age- and gender specific BMI cut-off points for children. Gross motor coordination was assessed by means of the Körperkoordinationstest für Kinder (KTK), a standardized test resulting in a motor quotient (MQ) based on which children with motor difficulties can be identified.
RESULTS: Childhood overweight and particularly obesity were found to result in poorer KTK performances, with the most pronounced effects of BMI on those items requiring physical properties next to coordination. Overall KTK performance was featured by a BMI x AGE interaction (F = 4.99, p < 0.001). Whereas normal-weight children performed at a similar level across age groups, the BMI related discrepancy became increasingly clear as children belonged to an older age group. Furthermore, approximately one fifth of the normal-weight participants was identified as being motor impaired, while that proportion increased to 43.3% and up to 70.8% in overweight and obese children, respectively.
CONCLUSIONS: Childhood overweight and obesity are detrimental to gross motor coordination. Moreover, results indicated a relative decline in gross motor competence against performance of normal-weight peers with increasing age. Although this outcome needs to be confirmed in future longitudinal research, it emphasizes the need for early and comprehensive intervention programs also focusing on motor skill improvement to boost overweight and obese children’s motivation to be physically active
The metabolism of beta-amino acids and carnosine in relation to supplementation and exercise
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