UVR exposure resulted in a decrease of the specific fluorescence
intensity F(350) of proteins eluted from hair shaft, Fig. 5. However,
one of nine subjects showed an increase of F(350) under UVR.
Probably the destructive effect of UVR was manifested foremost
in protein breakage and its subsequent elution rather than in tryptophan
degradation. In our study the hair samples were irradiated
at 254 nm where aromatic amino acids, disulfide bonds and melanin
participate in the absorption of the light [21]. The protective
effect of melanin could hardly explain the anomalous result
observed for the sample #6 (Fig. 5) since it was dark-brown hair,
like the other samples. But it was from a curly individual and
maybe hair shape played some role here.