Biomaterial Database

Metabolic pathways coupled to H+ transport in turtle urinary bladder. 1980

S Kelly, and T E Dixon, and Q Al-Awqati

Active H+ transport in the turtle urinary bladder is mediated by an ATPase. Although the source of ATP is usually mitochondrial oxidative phosphorylation, it is possible because of intracellular compartmentalization or cellular heterogeneity that one metabolic pathway exclusively provides ATP to the pump. To examine this we performed several types of experiments. In one, the coupling between the rate of transport and the rate of oxidation of 14C-labeled substrates was studied. We found that there was coupling between H+ transport and glucose, butyrate oleate, and beta-OH-butyrate oxidation. In another set of experiments we depleted turtle bladders of their endogenous substrates and tested the effect of a number of substrates on the rate of transport. We found that glucose, pyruvate, lactate, actetate, butyrate and beta-OH butyrate all stimulated H+ transport. In a third set of experiments we found no coupling between H+ transport and lactate production. Finally, we found that reduction of H+ transport by mucosal acidification resulted in an increase in epithelial cell ATP concentrations and a decrease in ADP levels. These results suggest that the H+ pump receives its ATP from carbohydrate and fatty acid oxidation. The changes in ATP and ADP levels provide an initial explanation for the coupling of H+ transport to the rate of cellular oxidative metabolism.

UI	MeSH Term	Description	Entries
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D007773	Lactates	Salts or esters of LACTIC ACID containing the general formula CH3CHOHCOOR.
D008297	Male		Males
D009829	Oleic Acids	A group of fatty acids that contain 18 carbon atoms and a double bond at the omega 9 carbon.	Octadecenoic Acids,Acids, Octadecenoic,Acids, Oleic
D010101	Oxygen Consumption	The rate at which oxygen is used by a tissue; microliters of oxygen STPD used per milligram of tissue per hour; the rate at which oxygen enters the blood from alveolar gas, equal in the steady state to the consumption of oxygen by tissue metabolism throughout the body. (Stedman, 25th ed, p346)	Consumption, Oxygen,Consumptions, Oxygen,Oxygen Consumptions
D001743	Urinary Bladder	A musculomembranous sac along the URINARY TRACT. URINE flows from the KIDNEYS into the bladder via the ureters (URETER), and is held there until URINATION.	Bladder,Bladder Detrusor Muscle,Detrusor Urinae,Bladder Detrusor Muscles,Bladder, Urinary,Detrusor Muscle, Bladder,Detrusor Muscles, Bladder
D002087	Butyrates	Derivatives of BUTYRIC ACID. Included under this heading are a broad variety of acid forms, salts, esters, and amides that contain the carboxypropane structure.	Butyrate,n-Butyrate,Butanoic Acids,Butyric Acids,Acids, Butanoic,Acids, Butyric,n Butyrate
D005947	Glucose	A primary source of energy for living organisms. It is naturally occurring and is found in fruits and other parts of plants in its free state. It is used therapeutically in fluid and nutrient replacement.	Dextrose,Anhydrous Dextrose,D-Glucose,Glucose Monohydrate,Glucose, (DL)-Isomer,Glucose, (alpha-D)-Isomer,Glucose, (beta-D)-Isomer,D Glucose,Dextrose, Anhydrous,Monohydrate, Glucose
D006863	Hydrogen-Ion Concentration	The normality of a solution with respect to HYDROGEN ions; H+. It is related to acidity measurements in most cases by pH	pH,Concentration, Hydrogen-Ion,Concentrations, Hydrogen-Ion,Hydrogen Ion Concentration,Hydrogen-Ion Concentrations
D006885	Hydroxybutyrates	Salts and esters of hydroxybutyric acid.	Hydroxybutyric Acid Derivatives,Hydroxybutyric Acids,Acid Derivatives, Hydroxybutyric