Biomaterial Database

Regulation of citrate transport and pyruvate dehydrogenase in rat kidney cortex mitochondria by bicarbonate. 1977

B H Robinson, and J Oei, and S Cheema-Dhadli, and M L Halperin

1. Bicarbonate increased citrate and 2-oxoglutarate accumulation when rat kidney cortex mitochondria were incubated with pyruvate or L(-)-palmitoyl carnitine in the presence of L-malate. 2. Bicarbonate stimulated the exit of citrate from mitochondria. The Km for bicarbonate was 13.5 mM and the Vmax was 0.59 nmol/min/mg of protein at 10 degrees. 3. The bicarbonate-stimulated exit of citrate from the mitochondria was prevented by inhibitors of the tricarboxylate, dicarboxylate, and phosphate transport systems. 4. The activity of pyruvate dehydrogenase was significantly increased by preincubation of rat kidney mitochondria with bicarbonate. This bicarbonate-induced activation was not observed in presence of inhibitors of citrate transport. Bicarbonate did not activate pyruvate dehydrogenase in rat heart mitochondria. Bicarbonate had no effect on pyruvate dehydrogenase activity in either broken mitochondria or whole tissue preparations. 5. The mechanism of this activation is discussed in the light of the known regulatory properties of pyruvate dehydrogenase, pyruvate carboxylase, and citrate synthase.

UI	MeSH Term	Description	Entries
D007656	Ketoglutaric Acids	A family of compounds containing an oxo group with the general structure of 1,5-pentanedioic acid. (From Lehninger, Principles of Biochemistry, 1982, p442)	Oxoglutarates,2-Ketoglutarate,2-Ketoglutaric Acid,2-Oxoglutarate,2-Oxoglutaric Acid,Calcium Ketoglutarate,Calcium alpha-Ketoglutarate,Ketoglutaric Acid,Oxogluric Acid,alpha-Ketoglutarate,alpha-Ketoglutaric Acid,alpha-Ketoglutaric Acid, Calcium Salt (2:1),alpha-Ketoglutaric Acid, Diammonium Salt,alpha-Ketoglutaric Acid, Dipotassium Salt,alpha-Ketoglutaric Acid, Disodium Salt,alpha-Ketoglutaric Acid, Monopotassium Salt,alpha-Ketoglutaric Acid, Monosodium Salt,alpha-Ketoglutaric Acid, Potassium Salt,alpha-Ketoglutaric Acid, Sodium Salt,alpha-Oxoglutarate,2 Ketoglutarate,2 Ketoglutaric Acid,2 Oxoglutarate,2 Oxoglutaric Acid,Calcium alpha Ketoglutarate,alpha Ketoglutarate,alpha Ketoglutaric Acid,alpha Ketoglutaric Acid, Diammonium Salt,alpha Ketoglutaric Acid, Dipotassium Salt,alpha Ketoglutaric Acid, Disodium Salt,alpha Ketoglutaric Acid, Monopotassium Salt,alpha Ketoglutaric Acid, Monosodium Salt,alpha Ketoglutaric Acid, Potassium Salt,alpha Ketoglutaric Acid, Sodium Salt,alpha Oxoglutarate,alpha-Ketoglutarate, Calcium
D007672	Kidney Cortex	The outer zone of the KIDNEY, beneath the capsule, consisting of KIDNEY GLOMERULUS; KIDNEY TUBULES, DISTAL; and KIDNEY TUBULES, PROXIMAL.	Cortex, Kidney
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D008928	Mitochondria	Semiautonomous, self-reproducing organelles that occur in the cytoplasm of all cells of most, but not all, eukaryotes. Each mitochondrion is surrounded by a double limiting membrane. The inner membrane is highly invaginated, and its projections are called cristae. Mitochondria are the sites of the reactions of oxidative phosphorylation, which result in the formation of ATP. They contain distinctive RIBOSOMES, transfer RNAs (RNA, TRANSFER); AMINO ACYL T RNA SYNTHETASES; and elongation and termination factors. Mitochondria depend upon genes within the nucleus of the cells in which they reside for many essential messenger RNAs (RNA, MESSENGER). Mitochondria are believed to have arisen from aerobic bacteria that established a symbiotic relationship with primitive protoeukaryotes. (King & Stansfield, A Dictionary of Genetics, 4th ed)	Mitochondrial Contraction,Mitochondrion,Contraction, Mitochondrial,Contractions, Mitochondrial,Mitochondrial Contractions
D011768	Pyruvate Dehydrogenase Complex	A multienzyme complex responsible for the formation of ACETYL COENZYME A from pyruvate. The enzyme components are PYRUVATE DEHYDROGENASE (LIPOAMIDE); dihydrolipoamide acetyltransferase; and LIPOAMIDE DEHYDROGENASE. Pyruvate dehydrogenase complex is subject to three types of control: inhibited by acetyl-CoA and NADH; influenced by the energy state of the cell; and inhibited when a specific serine residue in the pyruvate decarboxylase is phosphorylated by ATP. PYRUVATE DEHYDROGENASE (LIPOAMIDE)-PHOSPHATASE catalyzes reactivation of the complex. (From Concise Encyclopedia Biochemistry and Molecular Biology, 3rd ed)	Complex, Pyruvate Dehydrogenase,Dehydrogenase Complex, Pyruvate
D011773	Pyruvates	Derivatives of PYRUVIC ACID, including its salts and esters.
D002258	Carbonyl Cyanide m-Chlorophenyl Hydrazone	A proton ionophore. It is commonly used as an uncoupling agent and inhibitor of photosynthesis because of its effects on mitochondrial and chloroplast membranes.	CCCP,Carbonyl Cyanide meta-Chlorophenyl Hydrazone,Carbonylcyanide 4-Chlorophenylhydrazone,Propanedinitrile, ((3-chlorophenyl)hydrazono)-,Carbonyl Cyanide m Chlorophenyl Hydrazone,4-Chlorophenylhydrazone, Carbonylcyanide,Carbonyl Cyanide meta Chlorophenyl Hydrazone,Carbonylcyanide 4 Chlorophenylhydrazone
D002951	Citrates	Derivatives of CITRIC ACID.
D005246	Feedback	A mechanism of communication within a system in that the input signal generates an output response which returns to influence the continued activity or productivity of that system.	Feedbacks
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia