Photoprotection prevents TPN-induced lung procollagen mRNA in newborn guinea pigs

Abstract

Background: Photo-exposed intravenous multivitamin solutions (MVP) carry a peroxide load. Peroxidation induces gene expression of procollagen. We hypothesized that photo exposure of the MVP solution might promote pulmonary fibrosis. The aim of the study was to assess the potential for MVP to increase procollagen mRNA. Methods: Three day old guinea pigs were assigned to the following intravenous regimens, either: Control (C): 5% dextrose + 0.45% NaCl; C + 200 or 500 μM H 2O 2; C + 500 μM H 2O 2 + 10 μM GSSG; [C + 1% MVP ± {amino acids + lipids}] ± photoprotected. After 4 d, levels of pulmonary α1(I) procollagen mRNA and glutathione were determined. Results were compared by ANOVA. Results: Photoprotection of MVP or TPN prevents light induction of procollagen mRNA. The effect of MVP + light was associated with a peroxide load coupled with a low glutathione level. This was also observed with the 500 μM H 2O 2 group. The addition of GSSG prevented the increase of procollagen mRNA caused by H 2O 2. Conclusion: An oxidant stress caused by the infusion of peroxides in an organism with a weak antiperoxide capacity induces the transcription of the gene encoding for procollagen α1(I). The results confirm the antiperoxide activity of lung glutathione. Parenteral nutrition could be a clinical condition favoring the initiation of lung fibrosis, especially in premature newborn infants who have low glutathione levels.