Funkcionalne, biohemijske i histološke promene u kardiovaskularnom sistemu pacova u uslovima akutne i subhronične stimulacije metioninom

Abstract

Uvod: Polazeći od najnovijih literaturnih podataka o uticaju hipermetioninemije (i/ili hiperhomocisteinemije) u patogenezi oksidativnog stresa, aterogenezi i kanceru, pretpostavlja se da akutno i subhronično opterećenje metioninom ispoljava određene efekte na kardiovaskularni sistem, kao i na neke od biohemijskih, hemostatskih i inflamatornih parametara u krvi i tkivima pacova. Cilj: Generalni cilj ovog istraživanja je bilo ispitivanje funkcionalnih, biohemijskih i histoloških promena u kardiovaskularnom sistemu pacova u uslovima akutne i subhronične stimulacije metioninom. Materijal i metode: Istraživanje je dizajnirano kao eksperimentalna studija sprovedena na animalnom modelu ex vivo. Životinje su bile svrstane u 6 grupa sa po 8 životinja u svakoj grupi, ukupno 48 životinja. U akutnom tretmanu 60 minuta nakon akutno indukovane hipermetioninemije (aplikacijom DL–metionina), životinje su žrtvovane, prikupila se krv i određivali su se parametri oksidacionog stresa u plazmi pacova (enzimi: katalaza-CAT, glutation peroksidaza-GPx, superoksid dismutaza-SOD, i indeks lipidne peroksidacije-malondialdehid, MDA), kao i aktivnost enzima acetilholinesteraze u tkivu srca pacova. U subhroničnom tretmanu, posle 3 nedelje svakodnevnih intraperitonealnih aplikacija D,L–metionina (subhronična hipermetioninemija), sprovedene su iste pomenute analize, a takođe se izolovalo srce i aorta za histomorfološke promene. Pratili su se sledeći efekti: a. na promenu telesne mase pacova, b. na biohemijske parametre u serumu pacova, c. na hemostatske parametre u plazmi pacova, d. na postojanje histomorfoloških promena u srcu i aorti pacova, e. na parametre oksidacionog stresa u plazmi kod pacova (CAT, GPx, SOD i MDA), f. na aktivnost enzima acetilholinesteraze u tkivu srca pacova. Takođe su se ispitivali efekti istovremene subhronične primene metionina sa L-cisteinom ili sa N-acetil-Lcisteinom na već navedene parametre. Rezultati: Akutno primenjeni metionin je uzokovao pojačanu aktivnost katalaze i glutation preoksidaze dok nije menjao aktivnost acetilholinesteraze u tkivu srca i mozga pacova. Subhronična primena DL-metionina se povezuje sa različitim promenama većine ispitivanih biohemijskih parametara u krvi pacova, dok L-cistein i N-acetil-Lcistein nisu bitnije menjali postignute efekte metionina na biohemijske parametre u krvi pacova. Hronični tretman DL-metioninom može biti povezan sa sistemskim i lokalnim promenama u aktivnosti antioksidacionih enzima kao i sa nižom aktivnošću srčane acetilholinesteraze. Zaključak: Dobijeni rezultati daju originalan i veoma važan doprinos u razumevanju nastajanja poremećaja funkcije kardiovaskularnog sistema u uslovima akutnog i subhroničnog opterećenja metioninom, kao i uloge acetilholinesteraze u nastalim promenama, čime se dobija novi pogled na patogenezu kardiovaskularnih poremećaja u uslovima hiperhomocisteinemije.

: Introduction: Starting from the latest literature data on the effect of hypermethioninemia (and / or hyperchomocysteinemia) in the pathogenesis of oxidative stress, atherogenesis and cancer, it was assumed that acute and subchronic methionine load exhibits certain effects on the cardiovascular system, as well as on some biochemical, hemostatic and inflammatory parameters in the blood and rat tissues. Aim: The overall aim of this study was to investigate functional, biochemical and histological changes in the cardiovascular system of rats under conditions of acute and subchronic stimulation with methionine. Material and methods: The research was designed as an experimental study carried out on an animal ex vivo model. Animals were grouped into 6 groups with 8 animals in each group, a total of 48 animals. In acute treatment 60 minutes after acutely induced hypermethioninemia (DLmethionine application), animals were sacrificed, blood collected and parameters of oxidative stress in rat plasma were determined (enzymes: catalase-CAT, glutathione peroxidase-GPx, superoxide dismutase-SOD, and the lipid peroxidation index-malondialdehyde, MDA), as well as the activity of acetylcholinesterase enzymes in rat heart tissue. In subchronic treatment, after 3 weeks of intraperitoneal D,L-methionine daily intraperitoneal applications (subchronic hypermethiemia), the same abovementioned analyzes were performed, and the heart and aorta for histomorphological changes were isolated. The following effects were followed: a. on weight of rats, b. on biochemical parameters in rats serum, c. on hemostatic parameters in rat plasma, d. on the existence of histomorphological changes in the heart and aorta of the rat, e. on parameters of oxidative stress in plasma in rats (CAT, GPx, SOD and MDA), f. on the activity of acetylcholinesterase enzyme in rats' heart tissue. The effects of simultaneous subchronic application of methionine with L-cysteine or with N-acetyl-L-cysteine were also examined on the above-mentioned parameters. Results: Acutely administered methionine induced increased activity of catalase and glutathione preoxidase while the activity of acetylcholinesterase in the tissue of the heart and rat brain was altered. The subchronical application of DL-methionine was associated with various changes in the majority of rat biochemical parameters, while L-cysteine and N-acetyl-L-cysteine did not significantly alter the effects of methionine on the biochemical parameters in the rat's blood. Chronic DL-methionine treatment may be associated with systemic and local changes in the activity of antioxidant enzymes as well as with lower activity of cardiac acetylcholinesterase. Conclusions: The obtained results give a original and very important contribution in understanding the occurrence of cardiovascular system disorders in acute and subchronic methionine loading, as well as the role of acetylcholinesterase in the resulting changes, which brings a new perspective on the pathogenesis of cardiovascular disorders under conditions of hyperhomocysteinemia.