EFFECTS OF 5 PPM HYDROGEN-SULFIDE INHALATION ON BIOCHEMICAL-PROPERTIES OF SKELETAL-MUSCLE IN EXERCISING MEN AND WOMEN

This study compared the acute effects of 5 ppm hydrogen sulfide (H2S) inhalation (50% of its occupational exposure limit) on the biochemical properties of skeletal muscle in exercising men and women. Twenty-fiv e healthy volunteers, 13 men and 12 women, completed two 30-minute sub maximal tests at 50% of their predetermined maximal aerobic power (VO2 max) while breathing 0 ppm (control) or 5 ppm H2S from a specially des igned flow system in a single-blind manner. Immediately after exercise , biopsies were obtained from the vastus lateralis muscle under local anaesthesia. They were subsequently analyzed for concentrations of the following markers of anaerobic and aerobic metabolism:lactate (La), l actate dehydrogenase (LDH), citrate synthase (CS), and cytochrome oxid ase (CytOx). Repeated measures analysis of variance indicated that in men, the CS concentration decreased significantly (p=0.006) as a resul t of H2S exposure. There was also a tendency for their La and LDH conc entrations to increase and CytOx concentration to decrease in the pres ence of H2S, but these changes were not significant (p>0.05). In women no significant changes were observed in any of these biochemical prop erties. These results suggest that (1) exposure to H2S at 50% of its O EL might inhibit aerobic metabolism during exercise in healthy men, th ereby increasing their dependency on anaerobic metabolism; acid (2) th ere could be a significant gender difference in the acute response to sub-GEL exposures of H2S.