[The peroxidase content of human tears].
The peroxidase-(POD)-thiocyanate-hydrogenperoxide-system is a well-known antibacterial system, which has been demonstrated to exist, for example, in milk and saliva. Earlier investigations by van Haeringen et al. established a POD level in human tears of 10(3) units/l, yet the thiocyanate concentration was only about 0.2 mmol/l. Therefore van Haeringen et al. excluded the existence of a POD-thiocyanate-hydrogenperoxide antibacterial system in human tears because of the insufficient amount of thiocyanate in the tears examined. Instead of thiocyanate halides such as J- can also complete the POD hydrogen peroxide system as electron donors. Sufficient amounts of iodide can be expected after the application of iodine-containing eye drops or after local treatment with iodine-containing brine, as done in Bad Hall in Austria. Therefore, the above mentioned antibacterial system may be of importance if the POD-level is high enough (greater than 250 units/l). We investigated 22 tear samples from healthy persons: the POD levels were below 20 units/l in 19 cases; in 3 cases the POD concentration was found to be between 20 and 50 units/l. Therefore, in normal human tear fluid, not only the amount of thiocyanate but also the concentration of POD is too low for effective antimicrobial activity of the peroxidase-thiocyanate-hydrogenperoxide system. It is so far not known whether this system is effective under pathological conditions.
Buchberger
W
W
Rieger
G
G
D000293:Adolescent; D000328:Adult; D006801:Humans; D006861:Hydrogen Peroxide / Q000502:physiology; D008875:Middle Aged; D009195:Peroxidase / Q000502:physiology*; D013666:Tears / Q000201:enzymology* / Q000276:immunology; D013861:Thiocyanates / Q000502:physiology
D013861:Thiocyanates; D006861:Hydrogen Peroxide; D009195:Peroxidase; C031760:thiocyanate
Zum Peroxidase-(POD)-Gehalt der menschlichen Tränenflüssigkeit.