Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1992-4-6
pubmed:abstractText
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:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0031-3998
pubmed:author
pubmed:issnType
Print
pubmed:volume
31
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
196-201
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1992
pubmed:articleTitle
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.
pubmed:affiliation
Department of Biophysics, University of Rochester School of Medicine, New York 14642.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't