The H(2)S-releasing aspirin (ACS14) containing a dithiolethione moiety has been demonstrated to maintain the thromboxane-suppressing activity of the parent compound, but it seems to spare the gastric mucosa by affecting redox imbalance through increased H(2)S/glutathione (GSH) formation. Nevertheless, the mechanisms by which ACS14 is able to elevate the levels of these agents has not been fully elucidated so far. In this manuscript the effect of an acute ip administration of ACS14 and of its dithiolethione moiety (5-(4-hydroxyphenyl)-3H-1,2-dithiole-3-thione, ADTOH) on the overall thiol content of rat tissues and on the main enzymes involved in the maintenance of thiol homeostasis is reported. ACS14 and ADTOH treatments were shown to induce a significant increase not only of GSH but also of cysteine in plasma and in several rat tissues as well as of H(2)S plasma levels. Conversely, a significant decrease of homocysteine in most rat organs and in plasma was observed. Most of these phenomena are supposed to be linked to the elevated intracellular levels of cysteine induced by treatments with either ACS14 or ADTOH.