Age-Dependent Changes in Plasma Amino Acids Contribute to Alterations in Glycoxidation Products

Glycative stress is involved in the pathogenesis of various degenerative disorders. This study sought to determine the effect of age-related changes in amino acids on serum levels of pentosidine and carboxymethyl-lysine (CML) in healthy individuals.The subjects were 78 healthy individuals categorized into three age groups. The ages of the groups were as follows: 26 young adults (20-30 y, 25.2±3.03), 26 middle-aged adults (35-50 y, 39.46±6.97) and 26 older adults (60 y or older, 69.80±10.01). Serum levels of pentosidine and CML were measured by ELISA and levels of plasma amino acids were determined using HPLC.Serum levels of pentosidine and CML in the youngest group were higher than in the oldest group (p=0.026, 0.029, respectively). There was a positive correlation between the serum levels of pentosidine and CML and the levels of plasmaTyrosine (p=0.032, r=0.211 and p=0.037, r=0.224), Valine (p=0.037, r=0.224 and p=0.021, r=0.247) and Isoleucine (p=0.041, r=0.203 and p=0.021, r=0.247), respectively. Serum levels of pentosidine and CML may be modulated by the plasma levels of selected amino acids.Better understanding of the role of these selective amino acids might provide new perception of how glycation pathways may be altered and pave the way for new therapeutic principles.Stres izazvan glikacijom učestvuje u patogenezi raznih degenerativnih bolesti. U ovoj studiji namera je bila da se utvrdi uticaj promena u amino kiselinama koje su povezane sa starošću na serumske nivoe pentozidina i karboksimetillizina (CML) kod zdravih osoba.Ispitanike je činilo 78 zdravih osoba podeljenih prema starosti u tri kategorije. Starosne grupe su izgledale ovako: 26 mladih odraslih osoba (20–30 god, 25,2±3,03), 26 sredovečnih osoba (35–50 god, 39,46±6,97) i 26 starijih osoba (60 god. i više, 69,80±10,01). Nivoi pentozidina i CML u serumu mereni su tehnikom ELISA a nivoi amino kiselina u plazmi određeni su metodom HPLC.Nivoi pentozidina i CML u serumu u najmlađoj grupi bili su viši nego u najstarijoj grupi (p=0,026, odnosno 0,029). Postojala je pozitivna korelacija između serumskih nivoa pentozidina i CML i nivoa tirozina (p=0,032, r=0,211 i p=0,037, r=0,224), valina (p=0,037, r=0,224 i p=0,021, r=0,247) i izoleucina (p=0,041, r=0,203 i p=0,021, r=0,247) u plazmi. Serumski nivoi pentozidina i CML možda modulišu nivoe izabranih amino kiselina u plazmi.Bolje razumevanje uloge ovih izabranih amino kiselina može omogućiti novo shvatanje toga kako se mogu menjati putevi glikacije i otvoriti prostor za nove terapijske principe.