The DOI matches its Crossref record; 19 of the 19 references it cites were found in a registry or an index.
Prevention of neonatal hyperbilirubinemia by tin protoporphyrin IX, a potent competitive inhibitor of heme oxidation.
Open accessAbstract
The effects of various metalloporphyrins on hepatic heme oxygenase (EC 1.14.99.3) activity were examined in order to identify compounds that could inhibit heme degradation to bile pigment and might therefore be utilized to suppress the development of hyperbilirubinemia in the newborn. Among nine metal-protoporphyrin IX chelates (i.e., metal-hemes) studied, Sn-heme, Mn-heme, and Zn-heme substantially diminished heme oxygenase activity in vivo in the rat. These metalloporphyrins act as competitive inhibitory substrates in the heme oxygenase reaction but are not themselves oxidatively degraded. Sn-heme was the most potent enzyme inhibitor (Ki = 0.011 microM) in liver, spleen, kidney, and skin. Sn-heme administered to newborn animals within the first 72 hr after birth blocked the postnatal increase in heme oxygenase activity that occurs in various tissues. Its effect on the enzyme levels was prompt and protracted. Sn-heme administration also entirely prevented the development of hyperbilirubinemia that normally occurs postnatally. The effect of the metalloporphyrin in lowering the increased concentrations of serum bilirubin in neonates was prompt (within 1 day) and persisted throughout the 42 days after birth. No deleterious effects of Sn-heme treatment of the newborn were observed. This demonstrates that a synthetic metalloporphyrin that is a potent competitive inhibitor of heme oxidation can, when administered to the newborn, also prevent the hyperbilirubinemia that normally develops postnatally. The potential clinical implications of these findings are evident, and it is suggested that the pharmacological properties of Sn-heme and related synthetic metalloporphyrins merit further study.
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PROTEIN MEASUREMENT WITH THE FOLIN PHENOL REAGENT
Lowry, O., Rosebrough, N., Farr, A. L., & Randall, R. (1951) · Journal of Biological Chemistry · doi:10.1016/s0021-9258(19)52451-6 · Cited by 317,331
The enzymatic catabolism of hemoglobin: stimulation of microsomal heme oxygenase by hemin.
Tenhunen, R., Marver, H. S., & Schmid, R. (1970) · PubMed · Cited by 392
Maines, M. D., & Kappas, A. (1974) · Proceedings of the National Academy of Sciences · doi:10.1073/pnas.71.11.4293 · Cited by 261
Self-citationYaffe, S. J., Levy, G., Matsuzawa, T., & Baliah, T. (1966) · New England Journal of Medicine · doi:10.1056/nejm196612292752602 · Cited by 261
Maines, M., & Kappas, A. (1975) · Journal of Biological Chemistry · doi:10.1016/s0021-9258(19)41402-6 · Cited by 224
Self-citationBonkowsky, H. L., Tschudy, D. P., Collins, A., Doherty, J., Bossenmaier, I., Cardinal, R., & Watson, C. J. (1971) · Proceedings of the National Academy of Sciences · doi:10.1073/pnas.68.11.2725 · Cited by 203
Studies on the mechanism of induction of haem oxygenase by cobalt and other metal ions
Maines, M. D., & Kappas, A. (1976) · Biochemical Journal · doi:10.1042/bj1540125 · Cited by 201
Self-citationZinc · protoporphyrin is a selective inhibitor of heme oxygenase activity in the neonatal rat
Maines, M. D. (1981) · Biochimica et Biophysica Acta (BBA) - General Subjects · doi:10.1016/0304-4165(81)90465-7 · Cited by 183
Maurer, H. M., Wolff, J. A., Finster, M., Poppers, P. J., Pantuck, E. J., Kuntzman, R. G., & Convey, A. H. (1968) · The Lancet · doi:10.1016/s0140-6736(68)90415-7 · Cited by 119
Hematin Therapy for Acute Porphyria
Lamon, J. M., Frykholm, B. C., Hess, R. A., & Tschudy, D. P. (1979) · Medicine · doi:10.1097/00005792-197905000-00005 · Cited by 111
Cited by
Pharmacological and Clinical Aspects of Heme Oxygenase
Abraham, N. G., & Kappas, A. (2008) · Pharmacological Reviews · doi:10.1124/pr.107.07104 · Cited by 1,115
Self-citationDoré, S., Takahashi, M., Ferris, C. D., Hester, L. D., Guastella, D., & Snyder, S. H. (1999) · Proceedings of the National Academy of Sciences · doi:10.1073/pnas.96.5.2445 · Cited by 699
The Concise Guide to PHARMACOLOGY 2013/14: Enzymes
Alexander, S. P. H., Benson, H. E., Faccenda, E., Pawson, A. J., Sharman, J. L., Spedding, M., Peters, J. A., Harmar, A. J., & Collaborators, C. (2013) · British Journal of Pharmacology · doi:10.1111/bph.12451 · Cited by 425
Zakhary, R., Gaine, S. P., Dinerman, J. L., Ruat, M., Flavahan, N. A., & Snyder, S. H. (1996) · Proceedings of the National Academy of Sciences · doi:10.1073/pnas.93.2.795 · Cited by 401
Wilks, A., Black, S. M., Miller, W. L., & Ortiz de Montellano, P. R. (1995) · Biochemistry · doi:10.1021/bi00013a034 · Cited by 115
Metadata
- Authors
- Drummond, G. S., & Kappas, A.
- Venue
- Proceedings of the National Academy of Sciences
- Published
- 1981-10
- Volume
- 78
- Issue
- 10
- Pages
- 6466-6470
- ISSN
- 0027-8424 (ISSN-L)
- 1091-6490
- OpenAlex
- W1976866228
- Cited by
- 279
- References
- 19
- FWCI
- 9.40
- Type
- journal article
- Language
- en
- Open access
- bronze
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- Drummond, G. S., & Kappas, A. (1981). Prevention of neonatal hyperbilirubinemia by tin protoporphyrin IX, a potent competitive inhibitor of heme oxidation. Proceedings of the National Academy of Sciences. https://doi.org/10.1073/pnas.78.10.6466
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