Abstract
Introduction: Aging is accompanied by various degenerative changes in the body, including sarcopenia, which is characterized as a loss of muscle mass and function. Unhealthy eating habits and lack of physical activity are key factors that contribute to increased morbidity during aging. 
Methodology: Male Wistar rats in two age categories (4-5 months and 23-24 months old) were divided into four groups: C7 (control group), EX (exercise group), O1EX (combination of exercise and omega-3 fatty acids at a dose of 160 mg/kg), and O2EX (combination of exercise and omega-3 fatty acids at a dose of 320 mg/kg). The exercise program for the rats was performed on a treadmill. The intervention lasted a total of 7 weeks, with omega-3 fatty acid supplementation for the first 3 weeks and a combined intervention with exercise for the following 4 weeks. We determined sarcopenia-related markers in plasma and m. gastrocnemius and the levels of exercise-induced markers in the plasma and the brain (cortex, hippocampus) of the rats.
Results: Our results showed that aged rats do not have altered markers of sarcopenia in plasma, but have lower levels of irisin in the hippocampus. Exercise increased the level of follistatin in m.gastrocnemius in adult rats. A lower dose of omega-3 fatty acids in combination with exercise increased the levels of irisin in plasma and follistatin in m. gastrocnemius, decreased irisin levels in the cortex and hippocampus of adult rats, while it decreased plasma BDNF in aged rats. A higher dose of om-3 MK in combination with exercise caused an increase in myostatin levels in the plasma of adult rats but decreased the levels of myostatin and follistatin in m. gastrocnemius of aged rats. 
Conclusion: The results of our study suggest that the combined intervention can positively affect sarcopenia markers in aged rats, but we did not observe its positive effect on irisin and BDNF levels. Further studies are needed to determine the optimal dose of omega-3 fatty acids and type of exercise for the prevention and treatment of sarcopenia and for the influence of the levels of exercise-induced markers that play a role in healthy brain aging (Tab. 3, Ref. 75). Text in PDF www.lekarsky.herba.sk.
KEY WORDS: aging, omega-3 fatty acids, exercise, myokines, sarcopenia.
Lek Obz 2024, 73 (7): 228-235

Lívia GAJDOŠOVÁ 1, Barbora KATRENČÍKOVÁ 1, Zuzana PADUCHOVÁ 1, Mária CHOMOVÁ 1, Martina HORVÁTHOVÁ 1, 
Lucia ANDREZÁLOVÁ 1, Zuzana ORSZÁGHOVÁ 1, Oľga ULIČNÁ 2, Jana MUCHOVÁ 1

1 Ústav lekárskej chémie, biochémie a klinickej biochémie, Lekárska fakulta Univerzity Komenského, Bratislava, prednosta prof. MUDr. L. Turecký, CSc.
2 Farmakobiochemické laboratórium III. internej kliniky, Lekárska fakulta Univerzity Komenského, Bratislava, prednostka doc. MUDr. M. Szántová, PhD.