A. O. Mykytenko¹*, V. V. Pletnov¹, A. O. Pysarenko²,
A. M. Cherniavska³, K. I. Balabanov², K. S. Neporada¹

¹Department of Bioorganic and Biological Chemistry,
Poltava State Medical University, Poltava, Ukraine;
²Faculty of Dentistry, Poltava State Medical University, Poltava, Ukraine;
³Medical Faculty No 1, Poltava State Medical University, Poltava, Ukraine;
*e-mail: a.mykytenko@pdmu.edu.ua

Received: 15 April 2026; Revised: 14 May 2026;
Accepted: 29 May 2026; Available on-line: 18 June 2026

Background. Sulfur dioxide (SO₂) is proposed as a novel gasotransmitter that is endogenously formed depending on the activity of aspartate aminotransferase, glutathione synthetase, and dihydrogen sulfide content­. SO₂ and its donors can potentially have a corrective effect in reducing oxidative stress-induced injuries under conditions of adaptation syndrome. Salivary glands are highly sensitive to stressors, but SO₂ role in these organs under stress and general adaptation syndrome is largely unknown. Objective. The aim of our study was to determine the effect of the inorganic SO₂ donor on the prooxidant-antioxidant balan­ce and dihydro­gen sulfide content in the salivary glands of rats under conditions of immobilization stress. Methods.­ Experiments were performed on 24 white male Wistar rats divided into groups: intact; injected intraperitoneally with SO₂ donor Na₂SO₃/NaHSO₃ (0.54 mmol/kg/0.18 mmol/kg) daily; immobilized on their backs for 1 h daily; injected intraperitoneally with Na₂SO₃/NaHSO₃ daily 30 min before immobilization. Animals were withdrawn from the experiment on the 5^th day, salivary glands were removed, homogenised, the supernatant was used for biochemical studies. Results. It was shown that the introduction of SO₂ donor against the background of the general adaptation syndrome modeling led to a decrease in the blood plasma content of corticosterone, mitigation of lipid peroxidation and oxidative damage of proteins, cystathionine β-synthase and cystathionine γ-lyase activation and dihydrogen sulfide content restoration in the salivary glands. Conclusions. It was concluded that correction of stress-induced changes in the salivary glands of rats with sulfur dioxide led to the prevention of the development of oxidative stress and the restoration of dihydrogen sulfide production from cystathionine β-synthase and cystathionine γ-lyase and an increase in the activity of aspartate aminotransferase.