PubMed · 4909708
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M Leutenegger, H Choisy, M Dufour, J Caron. 1970. [Hyperandrogeny in women].. https://pubmed.ncbi.nlm.nih.gov/4909708/
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Flavonoids and related structures (e.g., flavones, isoflavones, flavanones, catechins) exert various biological effects, including anticarcinogenic, antioxidant and (anti-)estrogenic effects, and modulation of sex hormone homeostasis. A key enzyme in the synthesis of estrogens from androgens is aromatase (cytochrome P450 19; CYP19). We investigated the effects of various natural and synthetic flavonoids on the catalytic activity and promoter-specific expression of aromatase in H295R human adrenocortical carcinoma cells. Natural flavones were consistently more potent inhibitors than flavanones. IC(50) values for 7-hydroxyflavone, chrysin, and apigenin were 4, 7, and 20 microM, respectively; for the flavanones 7-hydroxyflavanone and naringenin the IC(50) values were 65 and 85 microM, respectively. The steroidal aromatase inhibitor (positive control) 4-hydroxyandrostenedione had an IC(50) of 20 nM. The inhibition by apigenin and naringenin coincided with some degree of cytotoxicity at 100 microM. The natural flavonoid derivative rotenone (IC(50) 0.3 microM) was the most potent aromatase inhibitor tested. Several synthetic flavonoid and structurally related quinolin-4-one analogs inhibited aromatase activity. The most potent inhibitor was 4'-tert-butyl-quinolin-4-one (IC(50) 2 microM), followed by two 2-pyridinyl-substituted alpha-naphthoflavones (IC(50)s 5 and >30 microM). The two 2-pyridinyl-substituted gamma-naphthoflavones consistently produced biphasic concentration-response curves, causing about 1.5-fold aromatase induction at concentrations below 1 microM and inhibition above that level (IC(50)s 7 and >30 microM). The natural flavone quercetin and isoflavone genistein induced aromatase activity 4- and 2.5-fold induction, respectively, at 10 microM. This coincided with increased intracellular cAMP concentrations and increased levels of the cAMP-dependent pII and to a lesser extent 1.3 promoter-specific aromatase transcripts. These results shed light on the structure-activity relationships for aromatase inhibition as well as mechanisms of induction in human H295R cells.
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BACKGROUND: Pheochromocytoma is a rare disease of the chromaffin cells that secrete catecholamines. It may occur during pregnancy. Bilateral pheochromocytoma in pregnancy is even rarer. CASE: A 26-year-old woman, gravida 2, para 0-0-1-0, 18 weeks' pregnancy, was initially seen with elevated blood pressure (170/100 mmHg) and mild headache. The cause of hypertension was conventionally investigated and bilateral pheochromocytoma was finally searched for and found. Bilateral adrenalectomy was undertaken at 23 weeks' gestation and Cesarean section was performed at 31 weeks' gestation due to intrauterine growth retardation (IUGR) and compromised fetal well-being. The maternal outcome was uneventful and the baby was physiologically complicated only by neonatal jaundice. CONCLUSION: Pheochromocytoma should be searched for in the conventionally differential diagnosis in hypertension during pregnancy, especially in the young. Early diagnosis and proper management with medical treatment followed by surgical removal of the tumor usually result in good maternal and fetal outcomes.