Skip Navigation
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

National Institute of Environmental Health Sciences

Use this QR code to view the newest version of this document
Use this QR code to view the newest version of this document

Your Environment. Your Health.

Publication Detail

Title: Comparative effects of tin- and zinc-protoporphyrin on steroidogenesis: tin-protoporphyrin is a potent inhibitor of cytochrome P-450-dependent activities in the rat adrenals.

Authors: Trakshel, G M; Sluss, P M; Maines, M D

Published In Pediatr Res, (1992 Feb)

Abstract: Synthetic metalloporphyins inhibit formation of bilirubin by the heme oxygenase system, an ability that is of considerable experimental and clinical interest for suppression of jaundice in the newborn. The present investigation compares the consequences of treatment with Sn- and Zn-protoporphyrin on hemoprotein-dependent enzymes of the rat adrenals and corticosterone production and defines Sn-protoporphyrin as a potent toxin to adrenal functions. Treatment of rats with Sn-protoporphyrin (two doses of 50 mumols/kg, in 7 d) resulted in a marked reduction of 30-40% in cytochrome P-450-dependent adrenal microsomal 21 alpha-hydroxylase and mitochondrial 11 beta-hydroxylase activities. In the serum, the levels of corticosterone were reduced to about 70% of the control value. In addition, the mitochondrial cytochrome P-450SCC activity was decreased by about 50%. This decrease, however, could not be attributed to a reduced total heme level or an accelerated heme degradatory activity. Disruption by Sn-protoporphyrin of adrenal hemoprotein-dependent functions was not restricted to steroidogenic activities and encompassed drug metabolism activity of the organ; benzo(a)pyrene hydroxylase activity of both the microsomal and the mitochondrial fractions, as well as the microsomal NADPH-cytochrome P-450 reductase activity, were significantly reduced. Zn-protoporphyrin did not cause significant alterations in the above measured parameters although it too was effective in inhibiting the hepatic microsomal heme oxygenase activity. In light of the presently defined adverse effects of Sn-protoporphyrin on adrenal steroidogenesis, we suggest Zn-protoporphyrin is the agent of choice for potential use in treatment of hyperbilirubinemia in humans.

PubMed ID: 1542552 Exiting the NIEHS site

MeSH Terms: No MeSH terms associated with this publication

Back
to Top