Detail of "4238-71-5"

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Effects of 7,8-benzoflavone on skin tumor-initiating activities of various 7- and 12-substituted derivatives of 7,12-dimenthylbenz[a]anthracene in mice

Effects of 7,8-benzoflavone on skin tumor-initiating activities of various 7- and 12-substituted derivatives of 7,12-dimenthylbenz[a]anthracene in mice. DiGiovanni, J.; Slaga, T. J.; Viaje, A.; Berry, D. L.; Harvey, R. G.; Juchau, M. R. (Dep. Pharmacol., Univ. Washington Sch. Med., Seattle, Wash., USA). J. Natl. Cancer Inst., 61(1), 135-40 (English) 1978. CODEN: JNCIAM. ISSN: 0027-8874. DOCUMENT TYPE: Journal CA Section: 4 (Toxicology) The skin tumor-initiating activities of various 7- and 12-substituted derivs. of 7,12-dimethylbenz[a]anthracene (I) [57-97-6] were investigated in female outbred Charles River CD-1 mice. 7-Formyl-12-methylbenz[a]anthracene (7-CHO-12-MBA) [13345-61-4] at 740 nmol/mouse was an effective tumor initiator, at a dose 74-fold greater than that of I. 7,8-Benzoflavone (7,8-BF) [604-59-1] inhibited the tumor-initiating activity of 7-CHO-12-MBA by 51%. 12-Formyl-7-methylbenz[a]anthracene [17513-40-5] and 7,12-diformylbenz[a]anthracene [19926-22-8], applied at initiatingh doses of 740 and 704 nmol/mouse, resp., were much less active than 7-CHO-12-MBA. 7-Bromomethyl-12-methylbenz[a]anthracene (7-BRME-12-MBA) [16238-56-5] and 7-bromomethylbenz[a]anthracene (7-BRMEBA) [24961-39-5] were also investigated. 7-BRME-12-MBA was a more effective tumor initiator than 7-BRMEBA, but both were less active than I. 7,8-BF inhibited the tumor-initiating activity of 7-BRME-12-MBA and 7-BRMEBA by 34 and 54%, resp. 12-Bromomethyl-7-methylbenz[a]anthracene (12-BRME-7-MBA) [59230-81-8] was as active an initiator as 7-BRME-12-MBA. 7,8-BF inhibited tumor initiation with 12-BRME-7-MBA by 29%. Three naturally occurring flavones, quercetin [117-39-5], myricetin [529-44-2], and 4',5,7-trihydroxyflavonone [480-41-1], and the cytochrome P450, inhibitor 1-benzylimidazole [4238-71-5] were investigated after topical application (100 mg) for their effects on tumor initiation with I. Quercetin inhibited tumor initiation with I by 22%, whereas myricetin and 4',5,7-trihydroxyflavanone enhanced tumor initiation with I by 54 and 29%, resp. 1-Benzylimidazole had no effect. The abilities of the flavones and 1-benzylimidazole to inhibit aryl hydrocarbon hydroxylase [9037-52-9] in vitro did not correlate with their effects on tumor initiation with I.

The effects of platelet-derived contractile agents on human digital arteries

The effects of platelet-derived contractile agents on human digital arteries. Moulds, R. F. W.; Iwanov, V.; Medcalf, R. L. (R. Melbourne Hosp., Univ. Melbourne, Parkville 3050, Australia). Clin. Sci., 66(4), 443-51 (English) 1984. CODEN: CSCIAE. ISSN: 0143-5221. 50-67-9 and 74050-98-9 are also in the experiment. DOCUMENT TYPE: Journal CA Section: 1 (Pharmacology) Section cross-reference(s): 2 Platelets added to spiral arterial strips of human digital arteries 1 min after being aggregated by thrombin produced arterial contractile responses significantly greater than those produced by platelets added 20 min after aggregation. Various addns. during platelet aggregation and various pretreatments of the arterial strips indicated that there are 2 equipotent components to the contractile responses of blood vessels produced by the aggregation of platelets. One is labile, not produced when aggregation occurs in indomethacin [53-86-1] or the thromboxane synthetase antagonist 1-benzylimidazole [4238-71-5] and is probably produced by TXA2 [57576-52-0]. The other is stable, markedly reduced by the 5-HT [50-67-9] antagonist ketanserin [74050-98-9], and probably produced by 5-HT. 5-HT antagonists, in combination with a thromboxane synthetase inhibitor, may be of therapeutic benefit in clin. syndromes possibly mediated by platelet aggregation, such as cerebral transient ischemic attacks and coronary spasm. .