Regulation of citrulline synthesis in human enterocytes: Role of hypoxia and inflammation

BioFactors ◽  
2021 ◽  
Author(s):  
Morgane Couchet ◽  
Sandie Pestour ◽  
Charlotte Breuillard ◽  
Christelle Corne ◽  
John Rendu ◽  
...  
Keyword(s):  
Citrulline Synthesis

scholarly journals Enteral arginase II provides ornithine for citrulline synthesis

2011 ◽  
Vol 300 (1) ◽  
pp. E188-E194 ◽  
Author(s):  
Juan C. Marini ◽  
Bettina Keller ◽  
Inka Cajo Didelija ◽  
Leticia Castillo ◽  
Brendan Lee
Keyword(s):  
Small Intestine ◽  
Stable Isotope ◽  
Transgenic Mice ◽  
Small Intestinal Mucosa ◽  
Wild Type ◽  
Proline Utilization ◽  
Small Intestinal ◽  
Arginase Ii ◽  
Citrulline Synthesis

The synthesis of citrulline from arginine in the small intestine depends on the provision of ornithine. To test the hypothesis that arginase II plays a central role in the supply of ornithine for citrulline synthesis, the contribution of dietary arginine, glutamine, and proline was determined by utilizing multitracer stable isotope protocols in arginase II knockout (AII−/−) and wild-type (WT) mice. The lack of arginase II resulted in a lower citrulline rate of appearance (121 vs. 137 μmol·kg−1·h−1) due to a reduced availability of ornithine; ornithine supplementation was able to restore the rate of citrulline production in AII−/− to levels comparable with WT mice. There were significant differences in the utilization of dietary citrulline precursors. The contribution of dietary arginine to the synthesis of citrulline was reduced from 45 to 10 μmol·kg−1·h−1 due to the lack of arginase II. No enteral utilization of arginine was observed in AII−/− mice (WT = 25 μmol·kg−1·h−1), and the contribution of dietary arginine through plasma ornithine was reduced in the transgenic mice (20 vs. 13 μmol·kg−1·h−1). Dietary glutamine and proline utilization were greater in AII−/− than in WT mice (20 vs. 13 and 1.4 vs. 3.7 μmol·kg−1·h−1, respectively). Most of the contribution of glutamine and proline was enteral rather than through plasma ornithine. The arginase isoform present in the small intestinal mucosa has the role of providing ornithine for citrulline synthesis. The lack of arginase II results in a greater contribution of plasma ornithine and dietary glutamine and proline to the synthesis of citrulline.

scholarly journals Glutamine: precursor or nitrogen donor for citrulline synthesis?

2010 ◽  
Vol 299 (1) ◽  
pp. E69-E79 ◽  
Author(s):  
Juan C. Marini ◽  
Inka Cajo Didelija ◽  
Leticia Castillo ◽  
Brendan Lee
Keyword(s):  
Amino Acids ◽  
Current Literature ◽  
Ammonium Acetate ◽  
Carbon Skeleton ◽  
Amino Group ◽  
Amino Groups ◽  
Amido Group ◽  
Nitrogen Donor ◽  
Citrulline Synthesis

Although glutamine is considered the main precursor for citrulline synthesis, the current literature does not differentiate between the contribution of glutamine carbon skeleton vs. nonspecific nitrogen (i.e., ammonia) and carbon derived from glutamine oxidation. To elucidate the role of glutamine and nonspecific nitrogen in the synthesis of citrulline, l-[2-15N]- and l-[5-15N]glutamine and 15N-ammonium acetate were infused intragastrically in mice. The amino group of glutamine labeled the three nitrogen groups of citrulline almost equally. The amido group and ammonium acetate labeled the ureido and amino groups of citrulline, but not the δ-nitrogen. D5-glutamine also infused in this arm of the study, which traces the carbon skeleton of glutamine, was utilized poorly, accounting for only 0.2–0.4% of the circulating citrulline. Dietary glutamine nitrogen (both N groups) incorporation was 25-fold higher than the incorporation of its carbon skeleton into citrulline. To investigate the relative contributions of the carbon skeleton and nonspecific carbon of glutamine, arginine, and proline to citrulline synthesis, U-13Cn tracers of these amino acids were infused intragastrically. Dietary arginine was the main precursor for citrulline synthesis, accounting for ∼40% of the circulating citrulline. Proline contribution was minor (3.4%), and glutamine was negligible (0.4%). However, the glutamine tracer resulted in a higher enrichment in the ureido group, indicating incorporation of nonspecific carbon from glutamine oxidation into carbamylphosphate used for citrulline synthesis. In conclusion, dietary glutamine is a poor carbon skeleton precursor for the synthesis of citrulline, although it contributes both nonspecific nitrogen and carbon to citrulline synthesis.

Role of dactinomycin in the improved survival of children with Wilms' tumor

JAMA ◽  
1966 ◽  
Vol 195 (12) ◽  
pp. 1005-1009 ◽  
Author(s):  
D. J. Fernbach
Keyword(s):  
Wilms Tumor

Role of the allergist in diagnosis and management of patients with uveitis

JAMA ◽  
1966 ◽  
Vol 195 (3) ◽  
pp. 167-172 ◽  
Author(s):  
T. E. Van Metre
Keyword(s):  
Diagnosis And Management

The power of norms to sway fused group members

2018 ◽  
Vol 41 ◽  
Author(s):  
Winnifred R. Louis ◽  
Craig McGarty ◽  
Emma F. Thomas ◽  
Catherine E. Amiot ◽  
Fathali M. Moghaddam
Keyword(s):  
Evolutionary Anthropology ◽  
Normative Systems ◽  
Violent Extremism ◽  
Identity Fusion ◽  
Group Members

AbstractWhitehouse adapts insights from evolutionary anthropology to interpret extreme self-sacrifice through the concept of identity fusion. The model neglects the role of normative systems in shaping behaviors, especially in relation to violent extremism. In peaceful groups, increasing fusion will actually decrease extremism. Groups collectively appraise threats and opportunities, actively debate action options, and rarely choose violence toward self or others.

Elaborating the role of reflection and individual differences in the study of folk-economic beliefs

2018 ◽  
Vol 41 ◽  
Author(s):  
Kevin Arceneaux
Keyword(s):  
Decision Making ◽  
Individual Differences ◽  
Cognitive Processes ◽  
Evolutionary History ◽  
Behavioral Responses ◽  
History Of ◽  
Economic Beliefs

AbstractIntuitions guide decision-making, and looking to the evolutionary history of humans illuminates why some behavioral responses are more intuitive than others. Yet a place remains for cognitive processes to second-guess intuitive responses – that is, to be reflective – and individual differences abound in automatic, intuitive processing as well.

The role of affect in feelings of obligation

2020 ◽  
Vol 43 ◽  
Author(s):  
Stefen Beeler-Duden ◽  
Meltem Yucel ◽  
Amrisha Vaish
Keyword(s):  
Positive Emotions ◽  
The Creation ◽  
Sense Of Obligation

Abstract Tomasello offers a compelling account of the emergence of humans’ sense of obligation. We suggest that more needs to be said about the role of affect in the creation of obligations. We also argue that positive emotions such as gratitude evolved to encourage individuals to fulfill cooperative obligations without the negative quality that Tomasello proposes is inherent in obligations.

Refining our understanding of the “elephant in the room”

2020 ◽  
Vol 43 ◽  
Author(s):  
Andrew Whiten
Keyword(s):  
Social Cognition ◽  
Cultural Evolution ◽  
Cognitive Abilities ◽  
Critical Factors ◽  
Technological Culture

Abstract The authors do the field of cultural evolution a service by exploring the role of non-social cognition in human cumulative technological culture, truly neglected in comparison with socio-cognitive abilities frequently assumed to be the primary drivers. Some specifics of their delineation of the critical factors are problematic, however. I highlight recent chimpanzee–human comparative findings that should help refine such analyses.

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