Abstract

D-amino acids are present in the human body originating from diet, bacterial flora, and endogenous synthesis (at least for D-serine and, probably, D-aspartate). D-amino acids are involved in important physiological processes (e.g., D-serine and D-aspartate act on the N-methyl-D-aspartate receptor as co-agonist and agonist, respectively) and increasing evidence links D-amino acids to different pathological states. Determination of D-amino acids levels in blood is mainly based on enantiomeric separations by high performance liquid chromatography. Because of the low amount of D-enantiomers compared to the corresponding L-amino acids and the high background noise associated with biological matrices, positive and negative controls are absolutely required to obtain reliable values. Altered levels of D-serine in blood have been reported in several neurological and psychiatric disorders: it has been proposed as promising biomarker in schizophrenia, Alzheimer's disease, and amyotrophic lateral sclerosis. Indeed, D-serine levels seem an appropriate predictor of anti-depressant response in major depressive disorder and posttraumatic stress disorder, as well as a prognostic biomarker of early cognitive decline, especially when considering D-serine and D-proline levels simultaneously. Furthermore, D-amino acids seem useful biomarkers for pathologies not related to the central nervous system, such as pancreatic cancer and chronic kidney diseases. This is the first review focusing on the determination of blood levels of Damino acids as diagnostic and prognostic biomarkers. The experimental evidence of involvement of D-amino acids in various physiological pathways suggest investigating their levels in additional pathologies too, such as diabetes mellitus. In conclusion, the levels of D-amino acids in blood may represent novel diagnostic peripheral biomarkers for various disorders. Further studies are required to standardize/automatize the determinations and for confirming their clinical effectiveness.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.