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.

Prostaglandin E2-histamine in interactions on cAMP, cGMP, and acid production in isolated fundic glands

1982 ◽  
Vol 242 (1) ◽  
pp. G21-G26 ◽  
Author(s):  
R. A. Levine ◽  
K. R. Kohen ◽  
E. H. Schwartzel ◽  
C. E. Ramsay
Keyword(s):  
Prostaglandin E2 ◽  
Acid Secretion ◽  
Acid Production ◽  
Camp Production ◽  
Histamine Stimulation ◽  
Fundic Mucosa ◽  
Biochemical Responses ◽  
Camp Levels ◽  
Camp And Cgmp ◽  
Stimulation Of

Relations among cAMP, cGMP, acid production [measured by the intraglandular accumulation of [14C]aminopyrine (AP)], and prostaglandin E2 (PGE2) activity were studied in isolated glands from rabbit fundic mucosa. AP, cAMP, and cGMP responses to histamine, PGE2, and 3-isobutyl-1-methylxanthine (IMX) were compared with controls. Histamine and PGE2 significantly increased glandular cAMP levels twofold, and histamine and IMX stimulated AP uptake two- to fourfold. PGE2 significantly inhibited both histamine- and IMX-stimulated AP accumulation, but it did not alter basal AP uptake. PGE2 also decreased histamine-stimulated cAMP production but only at a low concentration (10(-7) M). This dose of PGE2 was near to the endogenous PGE2 content found in unstimulated glands (10(-8) M). Intraglandular cGMP levels in unstimulated glands (10(-8) M). Intraglandular cGMP levels were increased by IMX but not by PGE2 or histamine. It is concluded that histamine stimulation of acid secretion is mediated by cAMP, that secretory and biochemical responses to histamine are modulated by PGE2 because PGE2 antagonized histamine-stimulated cAMP and AP uptake, and that the rise in cAMP induced solely by PGE2 appears to be localized within nonparietal cells because PGE2 alone did not stimulate AP accumulation.

Oxygen Consumption in Platelets of Newborn Infants before and after Stimulation by Thrombin.

1976 ◽  
Vol 35 (03) ◽  
pp. 712-716 ◽  
Author(s):  
D. Del Principe ◽  
G Mancuso ◽  
A Menichelli ◽  
G Maretto ◽  
G Sabetta
Keyword(s):  
Oxygen Consumption ◽  
Cord Blood ◽  
Umbilical Cord ◽  
Newborn Infant ◽  
Umbilical Cord Blood ◽  
Newborn Infants ◽  
O2 Consumption ◽  
Adult Control ◽  
Healthy Newborn ◽  
Before And After

SummaryThe authors compared the oxygen consumption in platelets from the umbilical cord blood of 36 healthy newborn infants with that of 27 adult subjects, before and after thrombin addition (1.67 U/ml). Oxygen consumption at rest was 6 mμmol/109/min in adult control platelets and 5.26 in newborn infants. The burst in oxygen consumption after thrombin addition was 26.30 mμmol/109/min in adults and 24.90 in infants. Dinitrophenol did not inhibit the burst of O2 consumption in platelets in 8 out of 10 newborn infants, while the same concentration caused a decrease in 9 out of 10 adult subjects. Deoxyglucose inhibited the burst in O2 consumption in newborn infant and adult platelets by about 50%. KCN at the concentration of 10−4 M completely inhibited basal oxygen consumption but did not completely inhibit the burst after thrombin. At the concentration of 10−3 M, it inhibited both basal O2 consumption and the burst in infants and adult subjects.

The effect of 15 (R) 15 methyl prostaglandin E2 on gastric acid secretion in duodenal ulcer patients

1977 ◽  
Vol 13 (1) ◽  
pp. 115-124 ◽  
Author(s):  
Frederick W.K. Chen ◽  
Ho Soon Teck ◽  
Sultan M.M. Karim
Keyword(s):  
Duodenal Ulcer ◽  
Prostaglandin E2 ◽  
Acid Secretion ◽  
Gastric Acid Secretion ◽  
Gastric Acid

Effect of growth rate on the physiological rates of a chemostat-grown rotifer Encentrum linnhei

1988 ◽  
Vol 68 (1) ◽  
pp. 165-177 ◽  
Author(s):  
J. M. Scott
Keyword(s):  
Growth Rate ◽  
Oxygen Consumption ◽  
Steady State ◽  
Respiration Rate ◽  
Clearance Rate ◽  
Ingestion Rate ◽  
Physiological State ◽  
Growth Efficiency ◽  
Theoretical Figure ◽  
Marine Rotifer

The physiological rates of a normally omnivorous marine rotifer, Encentrum linnhei, were measured under the steady-state chemostat conditions in which the physiological state of the food-algae was kept constant whilst the rotifer growth rate was changed to preset levels. The specific clearance rate ranged between 50 and 100 μl/μg rotifer C/day (1.5–3.0 μ/rot/day) and varied hyperbolically with growth rate, a similar curve was obtained with the specific ingestion rate which varied between 1–2 μg C/μg rot C/day. A mean respiration rate of 0.45 μg C/μg rot C/day was obtained from oxygen consumption measurements. About 60‰ of ingested energy was found to be egested as paniculate matter and 9–4 °0 dissipated as heat, the latter comparing with a theoretical figure of 4–5‰.From rates, transfer efficiencies were obtained giving a mean net growth efficiency (K2) of 38‰ and a mean overall growth efficiency (K1 of 15‰. A curvilinear increase of Kl with growth rate contrasts with linear and hyperbolic responses found with brachionid rotifers.

GASEOUS METABOLISM IN PREMATURE INFANTS AT 32-34°C AMBIENT TEMPERATURE

PEDIATRICS ◽  
1964 ◽  
Vol 33 (1) ◽  
pp. 75-82
Author(s):  
Forrest H. Adams ◽  
Tetsuro Fujiwara ◽  
Robert Spears ◽  
Joan Hodgman
Keyword(s):  
Carbon Dioxide ◽  
Oxygen Consumption ◽  
Premature Infants ◽  
Rectal Temperature ◽  
Respiratory Quotient ◽  
Carbon Dioxide Production ◽  
Open Circuit ◽  
Co2 Production ◽  
O2 Consumption ◽  
Rate Of Increase

Thirty-four measurements of oxygen consumption, carbon dioxide production, respiratory quotient, and rectal temperature were made on 22 premature infants with ages ranging from 2½ hours to 18 days. The studies were conducted at 32-34°C utilizing an open circuit apparatus and a specially designed climatized chamber. Oxygen consumption and carbon dioxide production were lowest in the first 12 hours and increased thereafter. The rate of increase in O2 consumption was greater than that of CO2 production, with a consequent fall in respiratory quotient during the first 76 hours of life. A reverse relation of O2 consumption and CO2 production was found following the 4th day of life with a consequent rise in respiratory quotient. There was a close correlation between O2 consumption and rectal temperature regardless of age. A respiratory quotient below the value of 0.707 for fat metabolism was observed in 7 premature infants with ages ranging from 24 to 76 hours.

scholarly journals Sex-Related Differences in the Maximal Lactate Steady State

Sports ◽  
2018 ◽  
Vol 6 (4) ◽  
pp. 154 ◽  
Author(s):  
Paul Hafen ◽  
Pat Vehrs
Keyword(s):  
Heart Rate ◽  
Oxygen Consumption ◽  
Steady State ◽  
Respiratory Exchange Ratio ◽  
Time To Exhaustion ◽  
Distance Runners ◽  
Maximal Lactate Steady State ◽  
Training Tool ◽  
Significant Difference ◽  
Males And Females

The maximal lactate steady state (MLSS) is one of the factors that differentiates performance in aerobic events. The purpose of this study was to investigate the sex differences in oxygen consumption (VO2), heart rate (HR), and the respiratory exchange ratio (RER) at the MLSS in well-trained distance runners. Twenty-two (12 female, 10 male) well-trained distance runners (23 ± 5.0 years) performed multiple 30-min steady-state runs to determine their MLSS, during which blood lactate and respiratory gas exchange measures were taken. To interpret the MLSS intensity as a training tool, runners completed a time-to-exhaustion (TTE) run at their MLSS. The relative intensity at which the MLSS occurred was identical between males and females according to both oxygen consumption (83 ± 5 %O2max) and heart rate (89 ± 7 %HRmax). However, female runners displayed a significantly lower RER at MLSS compared to male runners (p < 0.0001; 0.84 ± 0.02 vs. 0.88 ± 0.04, respectively). There was not a significant difference in TTE at MLSS between males (79 ± 17 min) and females (80 ± 25 min). Due to the observed difference in the RER at the MLSS, it is suggested that RER derived estimates of MLSS be sex-specific. While the RER data suggest that the MLSS represents different metabolic intensities for males and females, the relative training load of MLSS appears to be similar in males and female runners.

Splanchnic blood flow, O2 consumption, removal of lactate, and output of glucose in highlanders

1977 ◽  
Vol 43 (2) ◽  
pp. 204-210 ◽  
Author(s):  
A. Capderou ◽  
J. Polianski ◽  
J. Mensch-Dechene ◽  
L. Drouet ◽  
G. Antezana ◽  
...  
Keyword(s):  
Blood Flow ◽  
Oxygen Consumption ◽  
Splanchnic Blood Flow ◽  
O2 Consumption ◽  
Arterial Lactate ◽  
Oxygen Breathing ◽  
Arterial Blood ◽  
Splanchnic Hemodynamics ◽  
Arterial Blood Glucose ◽  
Arteriovenous Difference

An impairment of gluconeogenesis has been proposed to explain the low arterial blood glucose of highlanders. Therefore, we studied splanchnic blood flow, splanchnic uptake of oxygen and lactate, and output of glucose in nine normal and six anemic highlanders at an altitude of 3,750 m. Splanchnic blood flow, arteriovenous difference for oxygen, and oxygen consumption were comparable at rest in both groups and in lowlanders from the literature, whereas splanchnic output of glucose, and uptake of lactate were approximately twice those in lowlanders. After 10 min of mild exercise in 12 subjects (7 normals, 5 anemic), no significant changes in splanchnic hemodynamics and metabolism were found. During 29% oxygen breathing in 8 subjects (5 normals, 3 anemics), arterial lactate, splanchnic uptake of lactate and output of glucose fell to normal sea-level values. We concluded that splanchnic hemodynamics are similar in adapted highlanders and in lowlanders, and that there is no evidence of an impaired gluconeogenesis at the altitude of the present study.

Conservative and nonconservative inhibitors of gastric acid secretion

1987 ◽  
Vol 253 (3) ◽  
pp. G359-G368 ◽  
Author(s):  
E. B. Ekblad ◽  
V. Licko
Keyword(s):  
Steady State ◽  
Acid Secretion ◽  
Initial Step ◽  
No Net Loss ◽  
Apparent Loss ◽  
H2 Antagonist ◽  
Flow Through ◽  
Ph Stat ◽  
High Concentrations ◽  
Continuous Presence

Inhibitors of the initial step (H2-antagonist) and of the final step (thiocyanate, SCN-; and nitrite, NO2-) were used to study the dynamics of acid secretion in isolated frog gastric mucosa. Tissues were mounted in flow-through chambers, and the acid secretion rate (SR) was recorded on a pH-stat microprocessor. Continuous presence of H2-antagonist decreases the SR to a lower steady state, and on removal the SR returns to basal SR, causing a net loss of acid, the nonconservative effect. The amount of lost acid is a unique function of exposure, thus, independent of the patterns (pulses or steps) of inhibition. In contrast, continuous presence of SCN- or NO2- (below 3 mM) results in an undershoot in SR with a return to basal SR, whereas at higher concentrations there is no return. Removal of these inhibitors causes an overshoot in SR with return to basal SR. The rebound acid is equal to acid suppressed by NO2- and low concentration of SCN-, resulting in no net loss of acid, the conservative effect, whereas at high concentrations of SCN- there is an apparent loss of acid. In maximally secreting tissue the overshoot of SR is not observed. However, the acid is not lost, merely delayed. In resting tissue NO2- also merely delays the exit of the acid produced in response to forskolin. The rebound acid is proposed to reside in a sequestered "acid" pool that is stable for at least 120 min. Results with NO2- and SCN- suggest an effect on a saturable exit enzyme, possibly the K+-H+-ATPase.

Mitochondrial function in the presence of myoglobin

1982 ◽  
Vol 53 (5) ◽  
pp. 1116-1124 ◽  
Author(s):  
R. P. Cole ◽  
P. C. Sukanek ◽  
J. B. Wittenberg ◽  
B. A. Wittenberg
Keyword(s):  
Oxygen Consumption ◽  
Steady State ◽  
Liquid Phase ◽  
Gas Phase ◽  
Oxygen Pressure ◽  
Oxygen Electrode ◽  
Oxygen Binding ◽  
Atp Production ◽  
Skeletal Muscle Mitochondria ◽  
The Difference

The effect of myoglobin on oxygen consumption and ATP production by isolated rat skeletal muscle mitochondria was studied under steady-state conditions of oxygen supply. A method is presented for the determination of steady-state oxygen consumption in the presence of oxygen-binding proteins. Oxygen consumed in suspensions of mitochondria was replenished continuously by transfer from a flowing gas phase. Liquid-phase oxygen pressure was measured with an oxygen electrode; the gas-phase oxygen concentration was held constant at a series of fixed values. Oxygen consumption was determined from the characteristic response time of the system and the difference in the steady-state gas- and liquid-phase oxygen concentrations. ATP production was determined from the generation of glucose 6-phosphate in the presence of hexokinase. During steady-state mitochondrial oxygen consumption, the oxygen pressure in the liquid phase is enhanced when myoglobin is present. Functional myoglobin present in the solution had no effect on the relation of mitochondrial respiration and ATP production to liquid-phase oxygen pressure. Myoglobin functions in this system to enhance the flux of oxygen into the myoglobin-containing phase. Myoglobin may function in a similar fashion in muscle by increasing oxygen flux into myocytes.

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