1. Data are presented on the oxidation and reduction of elementary sulphur by animal tissues in vitro, and the enhancing or otherwise effects of certain chemicals on these reactions are also shown.
2. All protein tissues seem to be capable of reducing sulphur to H₂S. Acid (HCl) inhibits this reaction whereas alkalies and alkaline salts enhance it.
3. Similarly, acid inhibits and alkalies and alkaline buffers increase the oxidation of reduced sulphur to sulphate. An alkaline medium, rich in oxygen, is therefore essential for the oxidation and detoxication of H₂S. This is readily accomplished in blood where these conditions are excellently fulfilled. Nevertheless, all tissues in the animal organism should be able to oxidize sulphides, in view of the fact that oxygen (e.g. H₂O₂) and phosphates (buffers) are present in all tissues.
4. The chief, if not the sole, effect of alkali on the oxidation of
sulphur seems to be to bind and concentrate the reduced sulphur in
the solution where it is then oxidized to sulphate by the oxygen
present in the corpuscles, in the case of blood, or by atmospheric
oxygen, in the case of other tissues. Furthermore, the oxidation
of sulphur by tissues under laboratory conditions is not influenced
by enzyme activity, in view of the fact that no difference was found
in the oxidation of H₂S by fresh, boiled or dried tissue suspensions
in an alkaline (Na₂CO₃) thymol-Ringer solution. As a matter of
fact the oxidation of H₂S also took place with relative ease in alkaline
(and buffer) solutions without the presence of tissues.
5. Similarly, the reduction of sulphur by animal tissues is not
due to enzyme activity because the reaction took place in tissues that
were boiled previous to their incubation with sulphur in a very
strong antiseptic solution.
6. A dose parallelism was found to exist, under laboratory
conditions, between the increases in the oxidation of sulphur and
(as a result of) the different percentages (on the dry basis) of modified
Steenbock salts 40 added to the intestinal contents of the rats fed an
ash and protein-free ration. This suggests that a diet with an excess
of base-forming elements may be of importance in the oxidation
and detoxication of sulphides in cases where large amounts of H₂S
are formed in the digestive tract.
7. The possibility of beneficial effects arising from injecting
(subcutaneously or intramuscularly) a colloidal suspension of sulphur
in an alkaline solution as an antidote in certain cases of acute
poisoning is discussed.