Reference

Activation of liver tryptophan oxygenase by hydrocortisone, hematin and tryptophan in streptozotocin-diabetic rats

Activation of liver tryptophan oxygenase by hydrocortisone, hematin and tryptophan in streptozotocin-diabetic rats. Sadler, Emily M.; Weiner, Myron; Buterbaugh, Gary G. (Sch. Pharm., Univ. Maryland, Baltimore, MD 21201, USA). Life Sci.Several reagents with their cas registry numbers 9014-51-1 and 73-22-3 are used here., 34(14), 1365-70 (English) 1984. CODEN: LIFSAK. ISSN: 0024-3205. DOCUMENT TYPE: Journal CA Section: 2 (Mammalian Hormones) Section cross-reference(s): 14 Hydrocortisone [50-23-7] caused similar increases in apoenzyme (inactive), holoenzyme (heme-satd.) and total (holoenzyme + apoenzyme) liver tryptophan oxygenase (TPO) [9014-51-1] activities in nondiabetic and diabetic rats. The ability of hematin [15489-90-4] to increase total TPO activity was less in diabetic rats. The largest differences between diabetic and nondiabetic rats were found with L-tryptophan [73-22-3] which increased total TPO and holoenzyme activities 300 and 650%, resp. in nondiabetic rats. However, tryptophan increased both apoenzyme (unchanged in nondiabetic rats) and holoenzyme activities by 300% in diabetic rats. Thus, in the diabetic state, the TPO-heme conjugation process is impaired, esp. substrate-mediated TPO-heme satn. .

Ferrihemochrome-forming nitrogenous bases as possible substitutes for nitrite in cured products

Ferrihemochrome-forming nitrogenous bases as possible substitutes for nitrite in cured products. Koizumi, Chiaki; Leonor, Araceli; Maglalang, V.; Nonaka, Junsaku (Tokyo Univ. Fish., Tokyo, Japan). Nippon Suisan Gakkaishi, 43(4), 455-61 (English) 1977. CODEN: NSUGAF. DOCUMENT TYPE: Journal CA Section: 17 (Foods) Twenty-one bases were tested for their ability to form ferrihemochromes with hematin [15489-90-4], metmyoglobin, and urea-denatured myoglobin (Mb), in model systems at pH 6.0, 6.5, 7.0, and 8.0. Imidazole [288-32-4], histidylhistidine [2733-45-1], carnosine [305-84-0], phenylalanine Et ester [3081-24-1], tyrosine Et ester [949-67-7], and histidine Me ester [7389-87-9] were highly reactive to both hematin and denatured Mb, with imidazole the most reactive. The 2 histidyl peptides were more reacive than histidine [645-35-2]. In general, nitrogenous bases with a high degree of affinity for hematin also reacted well with denatured Mb. Based on these results, the possibility of using ferrihemochrome-forming nitrogenous bases as nitrite substitutes in cured meat was discussed.