David K. Stevenson, M.D.

Publication Details

  • Effect of light exposure on metalloporphyrin-treated newborn mice PEDIATRIC RESEARCH Schulz, S., Wong, R. J., Kalish, F. S., Zhao, H., Jang, K. Y., Vreman, H. J., Stevenson, D. K. 2012; 72 (2): 161-168


    Neonatal hyperbilirubinemia arises from increased bilirubin production and decreased bilirubin elimination. Although phototherapy safely and effectively reduces bilirubin levels, recent evidence shows that it has adverse effects. Therefore, alternative treatments are warranted. Metalloporphyrins, competitive inhibitors of heme oxygenase (HO), the rate-limiting enzyme in bilirubin production, effectively reduce bilirubin formation; however, many are photoreactive. Here, we investigated possible photosensitizing effects of chromium mesoporphyrin (CrMP) and zinc deuteroporphyrin bis-glycol (ZnBG).Administration of CrMP or ZnBG to 3-d-old mouse pups (3.75-30.0 ?mol/kg intraperitoneally) and exposure to cool white (F20T12CW) and blue (TL20W/52) fluorescent lights (+L) for 3 h, resulted in a dose-dependent mortality (50% lethal dose (LD50) = 21.5 and 19.5 ?mol/kg, respectively). In contrast to ZnBG, there was no significant difference in survival between the CrMP+L and CrMP groups. Following 30 ?mol/kg ZnBG+L, we found significant weight loss, decreased liver antioxidant capacities, and increased aspartate aminotransaminase levels. At 6-d post-light exposure, ZnBG+L-treated pups showed gross and histologic skin changes at doses >7.5 ?mol/kg. No lethality was observed following treatment with 30 ?mol ZnBG/kg plus exposure to blue light-emitting diodes. Phototoxicity of ZnBG was dependent on light source, emission spectrum, and irradiance.Low doses of ZnBG (<3.75 ?mol/kg) retained maximal HO inhibitory potency without photosensitizing effects, and therefore are potentially useful in treating neonatal hyperbilirubinemia.

    View details for DOI 10.1038/pr.2012.62

    View details for Web of Science ID 000306862000007

    View details for PubMedID 22580722

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