The effects of ammonium chloride and bicarbonate on the activity of glutaminase in isolated liver mitochondria.
نویسندگان
چکیده
1. Glutamine hydrolysis in liver mitochondria was studied by measuring the production of glutamate under conditions where this compound could not be further metabolized. 2. Glutaminase activity in intact mitochondria was very low in the absence of activators. 3. Glutamine hydrolysis was markedly stimulated by NH4Cl and also by HCO3- ions. 4. The stimulation by each of these compounds was much decreased if the mitochondria were uncoupled. 5. Maximum rates of glutamine hydrolysis required the addition of phosphate. A correlation was observed between the activity of glutaminase in the presence of NH4Cl plus HCO3- and the intramitochondrial content of ATP. 6. In disrupted mitochondria, NH4Cl stimulated glutaminase to a much smaller extent than in intact mitochondria. The NH4Cl stimulation in disrupted mitochondria was much increased by the addition of ATP. KHCO3 also stimulated glutaminase activity in disrupted mitochondria, and ATP increased the magnitude of this stimulation. 7. It was concluded that maximum rates of glutaminase activity in liver mitochondria require the presence of phosphate, ATP and either HCO3- or NH4+. A comparison of the results obtained on intact and broken mitochondria indicates that these effectors have a direct effect on the glutaminase enzyme system rather than an indirect effect mediated by changes in transmembrane ion gradients or in the concentrations of intramitochondrial metabolites.
منابع مشابه
Study of the Effects of ATP Suppliers and Thiol Reductants on Toxicity of Pioglitazone in Isolated Rat Liver Mitochondria
Pioglitazone (PG) is one of thiazolidinediones used for the treatment of type II diabetes mellitus. Some reports of its hepatotoxicity exist, but the mechanism of its hepatotoxicity is not well known. In the present study, the protective effect of some ATP suppliers are investigated against mitochondrial toxicity of PG in isolated rat mitochondria. Mitochondrial viability was investigated by MT...
متن کاملStudy of the Effects of ATP Suppliers and Thiol Reductants on Toxicity of Pioglitazone in Isolated Rat Liver Mitochondria
Pioglitazone (PG) is one of thiazolidinediones used for the treatment of type II diabetes mellitus. Some reports of its hepatotoxicity exist, but the mechanism of its hepatotoxicity is not well known. In the present study, the protective effect of some ATP suppliers are investigated against mitochondrial toxicity of PG in isolated rat mitochondria. Mitochondrial viability was investigated by MT...
متن کاملInhibitory Effects of Resveratrol against Mitochondrial Toxicity Induced by Perfluorooctanoic Acid in Isolated Liver Mitochondria of Male Rats
Background and purpose: Resveratrol (RSV) is a naturally polyphenolic compound found in grapes and other plant sources. It has potent free radical scavenger and antioxidative properties.The aim of this study was to evaluate the protective effect of resveratrol against Perfluorooctanoic acid (PFOA) induced mitochondrial toxicity in isolated liver mitochondria. Materials and methods: Mitochondr...
متن کاملComparison of the Protective Effects of Curcumin and Nanocurcumin on Acrolein Induced Mitochondrial Toxicity Isolated from Rat Liver
Background and Objectives: Contact with acrolein rapidly reduces intracellular glutathione and its antioxidant capacity and causes mitochondrial dysfunction. The use of some polymeric nanocurcumin increases the stability of curcumin. In this study, the effect of these two, was investigated on acrolein-induced toxicity in mitochondria isolated from rat liver cells. Methods: In this experiment...
متن کاملEEffects of nano-curcumin and curcumin on the oxidant and antioxidant system of the liver mitochondria in aluminum phosphide-induced experimental toxicity
Objective(s): Aluminum phosphide (AlP) is commonly used pesticide which could cause poisoning mainly through the induction of oxidative stress. The present study aimed to evaluate the effects of nano-curcumin and curcumin on the oxidant and antioxidant system in the liver mitochondria using AIP-induced toxicity model.Materials and Methods: In this study, 36 male albino Wistar rats were ra...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- The Biochemical journal
دوره 176 3 شماره
صفحات -
تاریخ انتشار 1978