Abstract
Adult male jaundiced Gunn rats were exposed to monochromatic laser light at wavelengths 457.9, 476.5, 488.0 and 514.5 nanometers. The incident irradiance was 1.0mW/cm2. The serum bilirubin levels were determined at -24, 0, 24 and 48 hours of irradiation by the diazo reaction. Study candidates needed bilirubin levels at -24 and 0 hrs. of >7mg%,<10mg% and within lmg% of each other. Water and food was ad lib. Weight loss or Hct change of >5% of baseline were exclusion criteria. Data are expressed as % remaining diazo reactivity from baseline.
Maximal decreases in serum bilirubin levels were observed at 457.9 and 488.0 nanometers with significantly less change observed at 476.5 and 514.5 nanometers (P<0.05). These data confirm the maximal effect of “blue light” but the action spectrum appears not to be identical to the absorption spectrum of protein-bound bilirubin. Rather, It extends well beyond the 475nm limit usually cited. Two peaks suggest a more complex in vivo mechanism(s) than previously suspected.
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Gutcher, G., Yen, W., Luedtke, L. et al. 1316 THE LASER-DETERMINED IN VIVO ACTION SPECTRUM OF BILIRUBIN. Pediatr Res 15 (Suppl 4), 662 (1981). https://doi.org/10.1203/00006450-198104001-01345
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DOI: https://doi.org/10.1203/00006450-198104001-01345