Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:1.14.99.3 (heme oxygenase)
 4,196 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Repeated administration of human chorionic gonadotropin to rats results in a maximal depression of testicular microsomal heme and cytochrome P-450 levels at 24 h, followed by increases that plateau at pretreatment levels by day six. Associated with the depressed levels of microsomal heme and cytochrome P-450 is an increase of testicular microsomal heme oxygenase activity at 12-24 h. Testicular mitochondrial delta-aminolevulinic acid synthase activity was increased at 24 h, and remained elevated throughout the 9-day treatment period. Pretreatment with 1,4,6-androstatrien-3,17-dione, an aromatase inhibitor, failed to prevent the depression of testicular microsomal heme or cytochrome P-450 or increased heme oxygenase activity caused by repeated administration of human chorionic gonadotropin, and administration of estradiol benzoate failed to alter testicular microsomal heme oxygenase activity suggesting that these parameters were not related to altered testicular estrogen content caused by increased aromatase activity. These results suggest that increased testicular heme oxygenase activity is associated with decreased microsomal heme and cytochrome P-450 content during human chorionic gonadotropin-induced desensitization.
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PMID:Increased rat testicular heme oxygenase activity associated with depressed microsomal heme and cytochrome P-450 levels after repeated administration of human chorionic gonadotropin. 348 41

Exemestane (6-methyleneandrosta-1,4-diene-3,17-dione) is a synthetic steroidal inhibitor of the aromatase reaction that catalyzes the terminal and rate-limiting step of the biosynthesis of estrogens. It is active clinically in preventing, delaying progression of, and treating mammary cancers, many of which are estrogen receptor-positive. A striking feature of the structure of exemestane is an extended system of conjugated Michael reaction functions, which is also characteristic of inducers of a broad network of chemoprotective genes regulated by the Keap1 (Kelch-like ECA-associated protein)/Nrf2 (nuclear factor E2-related factor 2)/ARE (antioxidant response element) signaling system. These genes are largely involved in xenobiotic metabolism and antioxidative and anti-inflammatory protection, as well as the synthesis and reduction of glutathione. We show here that exemestane transcriptionally activates NAD(P)H:quinone oxidoreductase 1 (NQO1) and heme oxygenase 1 (HO-1), typical chemoprotective gene products, in a wide variety of mouse, rat, and human cells. It protects several cell lines against oxidative toxicity of tert-butyl hydroperoxide and 4-hydroxynonenal, against free radical damage arising from hypoxia-reoxygenation, and against UVA radiation damage. Exemestane also inhibits the inflammatory increases in inducible nitric oxide synthase (iNOS) in mouse macrophages exposed to LPS (lipopolysaccharide), thereby resembling the isothiocyanate sulforaphane derived from broccoli. Remarkably, combinations of exemestane and sulforaphane act highly synergistically, and this property is also displayed by several other phytochemicals. Thus, exemestane has a wide range of previously unrecognized protective activities, probably unrelated to aromatase inhibition. Its potential for reducing the risk, not only of breast cancer, but also of other chronic diseases that arise from inflammation, oxidative stress, and DNA-damaging electrophiles, requires exploration, particularly in view of the synergism with other phytochemicals.
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PMID:Relevance of anti-inflammatory and antioxidant activities of exemestane and synergism with sulforaphane for disease prevention. 2419 Oct 56