scholarly journals Mechanochemical Coupling in Flagella

1968 ◽  
Vol 52 (2) ◽  
pp. 283-299 ◽  
Author(s):  
C. J. Brokaw ◽  
B. Benedict
Keyword(s):  
Oxygen Consumption ◽  
Oxidative Metabolism ◽  
Acid Production ◽  
Energy Requirement ◽  
Beat Frequency ◽  
Radius Of Curvature ◽  
Mechanochemical Coupling ◽  
Tightly Coupled ◽  
Dilute Suspensions ◽  
Stoichiometric Relation

The relation between oxygen consumption and motility of Ciona spermatozoa has been measured by using pH stats to measure the acid production of spermatozoa swimming in dilute suspensions where their motility can be analyzed accurately, and calibrating the acid production by measuring it simultaneously with measurements of oxygen consumption, using more concentrated sperm suspensions. When the motility of the spermatozoa is inhibited by thiourea or by increased viscosity, their oxygen consumption decreases in proportion to the decrease in beat frequency. 80–85 % of their oxygen consumption appears to be tightly coupled to motility. The amount of movement-coupled oxidative metabolism per beat remains nearly constant, even when there are significant changes in the energy required per beat for movement against the viscous resistance of the medium. This implies that under these conditions, where the radius of curvature of flagellar bending remains constant, the amount of ATP used is determined by a stoichiometric relation to bending rather than by the energy requirement. The movement-coupled oxidative metabolism appears to be sufficient to generate approximately two molecules of ATP per beat for each molecule of the flagellar ATPase, dynein.

THE METABOLISM OF GLUCOSE BY RAT UTERUS TISSUE IN EARLY PREGNANCY

1971 ◽  
Vol 66 (1) ◽  
pp. 16-24 ◽  
Author(s):  
M. A. H. Surani ◽  
P. J. Heald
Keyword(s):  
Oxygen Consumption ◽  
Lactic Acid ◽  
Oxygen Uptake ◽  
Acid Production ◽  
Energy Requirement ◽  
Lactic Acid Production ◽  
Uterine Tissue ◽  
Rat Uterus ◽  
Marked Decline

ABSTRACT The oxygen uptake, lactic acid production and differential production of CO2 from [1-14C] glucose and [6-14C] glucose were examined in rat uterine tissue in vitro during the first nine days of pregnancy. After implantation had occurred the uterine areas containing the implanted blastocysts were studied separately from the remaining areas. It was found that the oxygen consumption of the tissues remained reasonably constant until day 7 of pregnancy and thereafter declined markedly in tissues from implanted areas and non implanted areas when expressed in terms of dry wt. When calculated on a DNA basis, the oxygen consumption of the implanted tissue still showed a marked decline by day 9 of pregnancy, whereas that of the non implanted tissue increased. Lactic acid production increased strongly in the implanted tissue but showed little change in the non implanted areas. The C1/C6 ratio increased significantly on day 3 of pregnancy and was consistantly and significantly higher in the implanted tissue in the non implanted tissue. The results are discussed in terms of the energy requirement for implantation.

Oxygen Consumption of Moths During Rest, Pre-Flight Warm-Up, and Flight In Relation to Body Size and Wing Morphology

1978 ◽  
Vol 76 (1) ◽  
pp. 11-25 ◽  
Author(s):  
GEORGE A. BARTHOLOMEW ◽  
TIMOTHY M. CASEY
Keyword(s):  
Oxygen Consumption ◽  
Aspect Ratio ◽  
Body Mass ◽  
Beat Frequency ◽  
Wing Beat ◽  
Wing Loading ◽  
Warm Up ◽  
Pooled Data ◽  
Wing Beat Frequency ◽  
Tightly Coupled

Morphometrics and oxygen consumption were studied in about 35 sphingids, 50 saturniids, and 20 other heterothermic moths belonging to various families. For the pooled data of all species the regression of oxygen consumption on mass in grams is described by the following equations: at rest, cm3/h = 0.402 g0.775; during hovering flight, cm3/h = 59.430.818; during warm-up, cm3 = 1.186 g0.898. Similar equations are presented for the families Saturniidae and Sphingidae. In sphingids and saturniids thoracic mass, wing length, and wing area increased with body mass, whereas wing loading and aspect ratio were independent of body mass. The sphingids had higher wing loading, aspect ratio, and wing beat frequency during flight than the saturniids. Wing beat frequency was more tightly coupled to morphological parameters in sphingids than in saturniids. The allometry of resting and active aerobic metabolism in heterothermic moths is compared with that of reptiles, mammals and birds. The scaling of oxygen consumption during flight in the moths is almost identical to that of bats and birds.

The energy requirement for sodium extrusion from a frog muscle

1954 ◽  
Vol 142 (908) ◽  
pp. 383-392 ◽  
Keyword(s):  
Oxygen Consumption ◽  
Energy Production ◽  
Energy Requirement ◽  
Metabolic Inhibitors ◽  
Sodium Efflux ◽  
External Potassium ◽  
Radioactive Sodium ◽  
Sodium Extrusion ◽  
Frog Sartorius ◽  
Made In

Parallel measurements have been made of the oxygen consumption and efflux of radioactive sodium in pairs of frog sartorius muscles. Calculation of the amount of secretory work necessary for an active extrusion of sodium at the observed rate showed that it would involve the utilization of about one-tenth of the energy available from resting metabolism.This figure may reasonably be regarded as a lower limit to the efficiency of the secretory mechanism. Some of the measurements were made in a potassium-free Ringer’s solution, and others with an external potassium concentration of 10mM. In the potassium-rich medium, both the sodium efflux and the oxygen consumption were increased, the proportion of the energy production required for sodium extrusion remaining roughly constant. The action of dinitrophenol and other metabolic inhibitors on the sodium efflux in sartorius muscles was examined, but there were no very obvious effects.

scholarly journals SELECTIVE INHIBITION BY PREPARATIONS OF STREPTOCOCCAL FILTRATES OF THE OXIDATIVE METABOLISM OF MITOCHONDRIA PROCURED FROM RABBIT MYOCARDIUM

1956 ◽  
Vol 104 (4) ◽  
pp. 577-587 ◽  
Author(s):  
Arthur S. Carlson ◽  
Aaron Kellner ◽  
Alan W. Bernheimer
Keyword(s):  
Oxygen Consumption ◽  
Oxidative Metabolism ◽  
Selective Inhibition ◽  
Sharp Reduction ◽  
Complete Cessation ◽  
Heat Labile ◽  
Streptolysin O ◽  
Selective Interference ◽  
Rabbit Myocardium

When solutions of streptolysin O were added to Warburg flasks containing, among other constituents, suspensions of mitochondria from the myocardium of rabbits and citrate, fumarate, or alpha-ketoglutarate as the substrate, there followed regularly a sharp reduction, and eventually complete cessation, of oxygen consumption. This phenomenon was not observed when succinate was the substrate in the flasks, the finding pointing to a selective interference with DPN as the underlying change. The agent in the solutions of streptolysin O responsible for this effect was shown to be a streptococcal product, and to be non-dialyzable and heat-labile. It differed from streptolysin O in that it did not appear to require prior activation with cysteine, and its effectiveness was not diminished by treatment with cholesterol or antistreptolysin globulins.

Oxygen consumption during cimetidine and prostaglandin E2 inhibition of acid secretion.

1978 ◽  
Vol 234 (5) ◽  
pp. E445
Author(s):  
L Y Cheung ◽  
F G Moody ◽  
K Larson ◽  
S F Lowry
Keyword(s):  
Oxygen Consumption ◽  
Steady State ◽  
Prostaglandin E2 ◽  
Acid Secretion ◽  
Acid Production ◽  
Inhibitory Action ◽  
O2 Consumption ◽  
Greater Curvature

Oxygen consumption was determined during cimetidine and 16,16-dimethyl prostaglandin E2 inhibition of acid secretion in exteriorized segments of the greater curvature of dog stomach. Steady-state acid secretion during histamine infusion correlated well with O2 consumption (r = 0.85, P less than 0.01). Cimetidine and 16,16-dimethyl prostaglandin E2 inhibition of acid secretion produced a reduction of oxygen consumption to resting levels. In contrast, oxygen consumption did not decrease appreciably during thiocyanate inhibition of acid secretion. These observations suggest that the inhibitory action of cimetidine and 16,16-dimethyl prostaglandin E2 precedes, whereas that of thiocyanate is at a point beyond the transfer of energy to the process of acid production.

scholarly journals Respiration and Glycolysis of Normal Human Lymphocytes

Blood ◽  
1966 ◽  
Vol 28 (2) ◽  
pp. 163-174 ◽  
Author(s):  
CARL J. HEDESKOV ◽  
VIGGO ESMANN
Keyword(s):  
Oxygen Consumption ◽  
Lactic Acid ◽  
Acid Production ◽  
Glucose Utilization ◽  
Aerobic Glycolysis ◽  
Human Lymphocytes ◽  
Lactic Acid Production ◽  
Crowding Effect ◽  
Normal Human

Abstract The metabolism of intact, normal, human lymphocytes in vitro was studied from a total of 80 subjects. Corrected for the metabolism of contaminating red blood cells, the glucose uptake, lactic acid production, and oxygen consumption were 62, 95, and 117 µmoles per 1010 lymphocytes per hour, respectively, provided the cells were incubated at concentrations greater than 40 x 106 lymphocytes per ml. At lower lymphocyte concentrations the oxygen consumption per lymphocyte rose steeply with decreasing cell concentration (crowding effect). A similar but weaker crowding effect was noted for the lactic acid production, but not for the utilization of glucose. The oxygen uptake was lower with 20 per cent than with 100 per cent oxygen as gas phase. Small Pasteur and Crabtree effects were demonstrated. The oxygen consumption and lactic acid production proceeded linear with time, while the glucose utilization was higher during the first 30 minutes of incubation than later on. It is concluded that lymphocytes have a low aerobic glycolysis accounting for 75 per cent of the glucose utilization. The respiration is severely inhibited at high cell concentrations and it is suggested that this is caused by an insufficient availability of oxygen to the cells.

Myocardial anaerobic metabolism in intact dogs

1963 ◽  
Vol 204 (3) ◽  
pp. 427-432 ◽  
Author(s):  
William A. Neill ◽  
Norman Krasnow ◽  
Herbert J. Levine ◽  
Richard Gorlin
Keyword(s):  
Energy Source ◽  
Oxygen Consumption ◽  
Oxidative Metabolism ◽  
Anaerobic Metabolism ◽  
Muscle Metabolism ◽  
Mechanical Work ◽  
Work Output ◽  
Heart Work ◽  
Anaerobic Energy ◽  
The Difference

Energy liberated from substrates of heart muscle metabolism appears as mechanical work and heat. External mechanical work and heat production of the left ventricle were compared with its oxygen consumption in intact dogs. Under control conditions, within the range of accuracy possible, the sum of work and heat was equal to energy from oxidative metabolism. Intravascular administration of cyanide increased heart work but reduced its rate of aerobic metabolism. During the cyanide effect, work plus heat exceeded the energy available from oxidative metabolism. The difference represents myocardial anaerobic metabolism. Since the energy of mechanical work output alone was greater than the myocardial aerobic energy source, a portion of the anaerobic energy liberated must have been converted to mechanical work.

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