Adrenocortical response during corrected and uncorrected hypercapnic acidosis

1962 ◽  
Vol 202 (2) ◽  
pp. 334-336 ◽  
Author(s):  
Arnold Mittelman ◽  
Serge J. Dos ◽  
Harold G. Barker ◽  
Gabriel G. Nahas
Keyword(s):  
Flow Rate ◽  
Venous Blood ◽  
Concomitant Administration ◽  
Cortisol Secretion ◽  
Hypercapnic Acidosis ◽  
Sharp Reduction ◽  
Venous Flow ◽  
Arterial Blood ◽  
Blood Ph ◽  
Before And After

Adrenal venous flow rate and cortisol synthesis have been measured in dogs subjected to hypercapnic acidosis before and after intravenous administration of 0.34 mm/kg of tris (hydroxymethyl) amino methane (THAM). A comparison was made of adrenal venous, peripheral venous, and arterial blood, pH, pCO2 and O2 saturation. During uncorrected hypercapnic acidosis the concentration of cortisol increased while adrenal venous flow rate decreased, but there was a significant increase in the minute output of cortisol. With the concomitant administration of 0.34 mM/kg THAM, adrenal venous flow rate doubled. However, since this enhanced flow rate was accompanied by a sharp reduction in cortisol secretion, the minute output of cortisol returned to control levels. The possibility of a direct effect of THAM on the adrenal vascular bed and synthetic processes is discussed. Throughout all the above experiments adrenal venous blood resembled arterial blood rather than peripheral blood in its pCO2, O2 saturation and pH.

Slow postcapillary pH changes in blood in anesthetized animals

1978 ◽  
Vol 45 (5) ◽  
pp. 674-680 ◽  
Author(s):  
A. Bidani ◽  
E. D. Crandall
Keyword(s):  
Blood Cells ◽  
Ph Change ◽  
Arterial Blood ◽  
Blood Ph ◽  
Pulmonary Capillary ◽  
Before And After ◽  
Equilibration Process ◽  
Contact Surfaces ◽  
Electrode Chamber

To investigate the hypothesis that blood pH and PCO2 continue to change after the blood leaves an exchange capillary, we used a rapidly responding, pressure-insensitive, stopped-flow pH electrode apparatus. Arterial blood from an anesthetized dog or cat is drawn through the apparatus into a syringe. Syringe movement is then suddenly stopped. Temperature and pH of the blood in the electrode assembly are continuously monitored, both before and after blood withdrawal ceases. Hemolysis was reduced by coating all blood contact surfaces with silicone and fasting the animal overnight, anesthetizing it with crystalline pentobarbital sodium, and allowing it to ventilate spontaneously. After stopping withdrawal, pH of blood in the electrode chamber continued to change, rising 0.01 unit with t1/2 of 4.4 s. After lysed blood was returned to the animal to provide carbonic anhydrase to the plasma, no pH change was seen after stopping the flow. The small pH rise occurring in arterial blood in vivo is probably due in large part to disequilibrium of [H+] between red blood cells and plasma at the end of the pulmonary capillary, the equilibration process being rate-limited by the extracellular CO2 hydration-dehydration reaction.

Systemic and hepatic hemodynamic changes in acute liver injury

1997 ◽  
Vol 272 (3) ◽  
pp. G617-G625 ◽  
Author(s):  
A. J. Makin ◽  
R. D. Hughes ◽  
R. Williams
Keyword(s):  
Blood Flow ◽  
Liver Injury ◽  
Hepatic Injury ◽  
Acute Liver Injury ◽  
Venous Blood ◽  
Marked Change ◽  
Arterial Blood Flow ◽  
Venous Flow ◽  
Subsequent Increase ◽  
Arterial Blood

Systemic and hepatic circulatory changes were studied in rats over the course of acute liver injury. Hepatic injury was induced by intraperitoneal injection of D-galactosamine (1.1 g/kg), and systemic and hepatic hemodynamics were measured over a 72-h period using a radioactive microsphere technique with direct measurement of arterial, portal venous, and hepatic venous blood oxygen content. Cardiac output increased to a maximum at 48 h, producing a marked increase (450%) in hepatic arterial blood flow so that it became the dominant supply of oxygen at the time of maximal hepatic injury. A subsequent increase in portal venous flow resulted in an overall increase in total hepatic blood flow of 500%. At this point the oxygen delivery by the hepatic arterial and portal venous systems was equal. These circulatory changes returned to control values by 72 h with recovery of liver function. These results demonstrate the development of a hyperdynamic circulation and a marked change in the normal relationship between portal venous and hepatic arterial blood flows that occur during hepatic injury.

Virtual Extracorporeal Circulation Process

1997 ◽  
Vol 20 (6) ◽  
pp. 341-351 ◽  
Author(s):  
F. Boschetti ◽  
F.M. Montevecchi ◽  
R. Fumero
Keyword(s):  
Flow Rate ◽  
Extracorporeal Circulation ◽  
Gas Flow ◽  
Venous Pressure ◽  
Venous Blood ◽  
Venous Flow ◽  
Pump Flow Rate ◽  
Urine Production ◽  
Diuretic Drugs ◽  
Temperature Levels

Virtual instruments for an extracorporeal circulation (ECC) process were developed to simulate the reactions of a patient to different artificial perfusion conditions. The computer simulation of the patient takes into account the hydraulic, volume, thermal and biochemical phenomena and their interaction with the devices involved in ECC (cannulae dimensions, oxygenator and filter types, pulsatile or continuous pump and thermal exchangers). On the basis of the patient's initialisation data (height, weight, Ht) and perfusion variables (pump flow rate, water temperature, gas flow rate and composition) imposed by the operator, the virtual ECC monitors simulated arterial and venous pressure tracings in real time, along with arterial and venous flow rate tracings, urine production tracing and temperature levels. Oxyhemoglobin arterial and venous blood saturation together with other related variables (pO2, pCO2, pH, HCO3) are also monitored. A drug model which allows the simulation of the effect of vasodilator and diuretic drugs is also implemented. Alarms are provided in order to check which variables (pressure, saturation, pH, urine flow) are out of the expected ranges during the ECC simulation. Consequently the possibility of modifying the control parameters of the virtual devices of the ECC in run-time mode offers an interaction mode between the operator and the virtual environment.

Acute Ammonia Toxicity and Ammonia Excretion in Rainbow Trout (Salmo gairdneri)

1979 ◽  
Vol 36 (6) ◽  
pp. 621-629 ◽  
Author(s):  
Betty A. Hillaby ◽  
David J. Randall
Keyword(s):  
Rainbow Trout ◽  
Ammonia Excretion ◽  
Hydrogen Ion ◽  
Ammonia Toxicity ◽  
Salmo Gairdneri ◽  
Mean Values ◽  
Arterial Blood ◽  
Blood Ph ◽  
Before And After ◽  
Total Ammonia

Acute ammonia toxicity in rainbow trout (Salmo gairdneri) was studied by intraarterial injection of NH4Cl and NH4HCO3. Hydrogen ion and total ammonia concentrations were measured in blood sampled from the dorsal aorta both before and after injection. Although injection of NH4HCO3 increased arterial blood pH, and injection of NH4Cl decreased arterial blood pH, the same dose of each was required to kill fish. While the un-ionized form of ammonia in water has been shown to be toxic, in the blood either the ionized form or the total ammonia load is toxic to fish. Ammonia levels were measured in pre- and postbranchial blood. Mean values were not significantly different, but paired values indicated a fall in blood ammonia due to excretion across the gills. There appears to be a more rapid excretion of ammonia following NH4HCO3 infusions, which result in higher un-ionized ammonia levels in blood compared with those following NH4Cl infusions. These results are consistent with the hypothesis that ammonia is excreted in the un-ionized form. Key words: un-ionized ammonia, ionized ammonia, gills, pH, blood

Slow postcapillary changes in blood pH in vivo: titration with acetazolamide

1978 ◽  
Vol 45 (4) ◽  
pp. 565-573 ◽  
Author(s):  
A. Bidani ◽  
E. D. Crandall
Keyword(s):  
Carbonic Anhydrase ◽  
Transport Processes ◽  
Arterial Blood ◽  
Blood Ph ◽  
Pulmonary Capillaries ◽  
Before And After ◽  
Time Courses ◽  
Electrode Chamber ◽  
Good Agreement

A stopped-flow pH electrode apparatus was used to investigate the mechanisms underlying slow changes in plasma pH (pHO) after blood leaves the pulmonary capillaries in carbonic anhydrase-inhibited animals. After acetazolamide was administered to an anesthetized dog or cat, arterial blood was withdrawn through the electrode apparatus into a syringe. Syringe movement was then suddenly stopped. Temperature and pHO of the blood in the electrode chamber were monitored both before and after blood withdrawal ceased. After stopping flow, pHO of the blood in the electrode chamber a) rose 0.02 after a dose of about 1 mg/kg acetazolamide; b) did not change after a dose of about 2 mg/kg acetazolamide; and c) fell 0.10 after a dose greater than about 5 mg/kg acetazolamide. With reasonable red cell and plasma carbonic anhydrase activities assumed for each dose level of acetazolamide, a computer model of the reaction and transport processes occurring in blood after gas exchange in the lung yielded predicted time courses of pHo that were in good agreement with the experimental results. The observed slow pHo changes are largely a result of disequilibrium of [H+] between red blood cells and plasma as blood leaves the pulmonary capillaries.

The Effect of Hypoxia Upon the Partial Pressure of Gases in the Blood and Water Afferent and Efferent to the Gills of Rainbow Trout

1967 ◽  
Vol 46 (2) ◽  
pp. 317-327 ◽  
Author(s):  
G. F. HOLETON ◽  
D. J. RANDALL
Keyword(s):  
Rainbow Trout ◽  
Anaerobic Metabolism ◽  
Venous Blood ◽  
Fold Increase ◽  
Arterial Blood ◽  
Blood Ph ◽  
Oxygen Capacity ◽  
Percentage Saturation ◽  
Progressive Hypoxia ◽  
Red Cell Count

1. The rate of oxygen uptake by rainbow trout does not alter during progressive deoxygenation of the environment. Blood lactate, however, shows a significant increase, indicating an increase in anaerobic metabolism during hypoxia. 2. The percentage utilization of oxygen from the water decreased from 55% to approximately 20% during hypoxia and was associated with a 13-fold increase in ventilation volume. 3. The arterial blood of a trout resting in aerated water was 95-100% saturated: the Po2 was 122 mm. Hg and the Pco2 was 1-1.5 mm. Hg. 4. The venous blood of a resting trout was 70% saturated, had a Po2 of 35 mm. Hg and a Pco2, of 2.5 mm. Hg. 5. During hypoxia the percentage saturation of the arterial blood decreased to 37% and that of the venous blood to 3%. The P o2 in the arterial blood was 10 mm. Hg; in the venous blood, 6 mm. Hg. The Pco2 in the arterial blood was 3.5-4 mm. Hg; in the venous blood, 4.5-5.00 mm. Hg respectively. 6. The ability of the fish to withstand hypoxia was related to the oxygen capacity of the blood, which was on average 9 vol.%. The red blood cells swelled during hypoxia, the hematocrit increased, but the red cell count did not alter. 7. Blood pH was 7.7, falling to 7.4 during hypoxia. 8. Cardiac output did not change during progressive hypoxia in the water, stroke volume increased to offset the decrease in heart rate.

Effect of Acupuncture on Bronchial Asthma

1976 ◽  
Vol 51 (5) ◽  
pp. 503-509 ◽  
Author(s):  
D. Y. C. Yu ◽  
S. P. Lee
Keyword(s):  
Smooth Muscle ◽  
Bronchial Asthma ◽  
Flow Rate ◽  
Clinical Remission ◽  
Blood Gas ◽  
Arterial Blood Gas ◽  
Arterial Blood ◽  
Before And After ◽  
The Mean ◽  
Needle Acupuncture

1. Needle acupuncture was performed at three sites in twenty patients in a clinical attack of bronchial asthma. 2. In all patients the symptoms of bronchoconstriction improved during the attacks when the correct site was stimulated, and in five patients wheezing was abolished. 3. Stimulation at the correct site produced a significant increase in the mean FEV1·0 (58%) and FVC (29%) but not in maximal mid-expiratory flow rate (MMFR; 76%), when compared with the findings before acupuncture, along with a significant fall in the Pa,co2 and an insignificant fall in Pa,o2. A mild tachycardia was also observed. 4. After acupuncture a greater improvement in FEV1·0, FVC and MMFR was produced by inhalation of isoprenaline. 5. No significant changes in FEV1·0, FVC, MMFR, pulse rate or arterial blood gas tensions occurred after acupuncture at control sites. 6. In four of the patients during clinical remission acupuncture was performed before and after histamine aerosol challenge, but there was no effect on either the severity or the duration of the histamine-induced bronchoconstriction. 7. It is concluded that acupuncture probably reduced the reflex component of the bronchoconstriction, but failed to influence direct smooth muscle constriction caused by histamine.

scholarly journals Hemodialysis and Plasma Oxylipin Biotransformation in Peripheral Tissue

Metabolites ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 34
Author(s):  
Tong Liu ◽  
Inci Dogan ◽  
Michael Rothe ◽  
Julius V. Kunz ◽  
Felix Knauf ◽  
...  
Keyword(s):  
Epoxide Hydrolase ◽  
Venous Blood ◽  
Blood Stream ◽  
Arterial Blood ◽  
Cardiovascular Morbidity And Mortality ◽  
Before And After ◽  
Stage Renal Disease ◽  
End Stage ◽  
The Impact ◽  
Esrd Patients

(1) Background: Factors causing the increased cardiovascular morbidity and mortality in hemodialysis (HD) patients are largely unknown. Oxylipins are a superclass of lipid mediators with potent bioactivities produced from oxygenation of polyunsaturated fatty acids. We previously assessed the impact of HD on oxylipins in arterial blood plasma and found that HD increases several oxylipins. To study the phenomenon further, we now evaluated the differences in arterial and venous blood oxylipins from patients undergoing HD. (2) Methods: We collected arterial and venous blood samples in upper extremities from 12 end-stage renal disease (ESRD) patients before and after HD and measured oxylipins in plasma by LC-MS/MS tandem mass spectrometry. (3) Results: Comparison between cytochrome P450 (CYP), lipoxygenase (LOX), and LOX/CYP ω/(ω-1)-hydroxylase metabolites levels from arterial and venous blood showed no arteriovenous differences before HD but revealed arteriovenous differences in several CYP metabolites immediately after HD. These changes were explained by metabolites in the venous blood stream of the upper limb. Decreased soluble epoxide hydrolase (sEH) activity contributed to the release and accumulation of the CYP metabolites. However, HD did not affect arteriovenous differences of the majority of LOX and LOX/CYP ω/(ω-1)-hydroxylase metabolites. (4) Conclusions: The HD treatment itself causes changes in CYP epoxy metabolites that could have deleterious effects in the circulation.

Buffering of hypercapnic acidosis by sodium carbonate

1962 ◽  
Vol 202 (1) ◽  
pp. 73-76 ◽  
Author(s):  
Gabriel G. Nahas ◽  
Driss Hassam ◽  
Martin H:son Holmdahl ◽  
William M. Manger
Keyword(s):  
Cerebrospinal Fluid ◽  
Fluid Pressure ◽  
Plasma Catecholamine ◽  
Hypercapnic Acidosis ◽  
Apneic Oxygenation ◽  
Arterial Blood ◽  
Blood Ph ◽  
Acid Load ◽  
Ecg Alterations ◽  
Circulatory Disturbances

Eight dogs were given 0.15–0.18 m solution of Na2CO3 i.v. during 1 hr of apneic oxygenation. Arterial blood pH was maintained within .1 unit of normal, whereas cerebrospinal fluid pH fell from 7.39 to 7.01. PaCOCO2 increased from 31 to 153 mm Hg, plasma HCO–3 from 18.3 to 72.7 mm/liter, Na+ from 147 to 182 mEq/liter, and osmolality from 336 to 407 mOs/liter. In the cerebrospinal fluid HCO–3 rose only from 21.5 to 30.6 mm/liter. Diuresis was maintained, but the rate of urine excreted during apnea was always lower than the rate of fluid given. Bradycardia, ECG alterations, and extreme variations in blood pressure were observed during apneic oxygenation. Cerebrospinal fluid pressure increased, as did plasma catecholamine levels and blood sugar. Two animals died shortly after the end of the experiment. Na2CO3 administration while maintaining blood pH constant did not offset the circulatory disturbances created by the acid load of apneic oxygenation.

Ultradian adrenocortical and circulatory oscillations in conscious dogs

1990 ◽  
Vol 258 (3) ◽  
pp. R578-R590 ◽  
Author(s):  
L. A. Benton ◽  
F. E. Yates
Keyword(s):  
Heart Rate ◽  
Blood Flow ◽  
Venous Blood ◽  
Time History ◽  
Secretion Rate ◽  
Conscious Dogs ◽  
Cortisol Secretion ◽  
Arterial Blood ◽  
Tightly Coupled ◽  
Adrenal Glucocorticoid

We examined adrenal blood flow, cortisol secretion rate, concentration of cortisol in adrenal venous blood, mean arterial blood pressure, and heart rate in unrestrained conscious dogs, sampling at 15-20 s, 5 min, or 10 min during experiments lasting from 30 min to 8 h. Time history analysis designed for short, noisy time series detected three significant ultradian oscillatory periods: approximately 3, 6, and 90 min. Circulatory variables (systemic mean arterial pressure, heart rate, and adrenal blood flow) showed all three. Cortisol secretion rate showed the 3- and 90-min oscillations but not the 6-min oscillation. Adrenal glucocorticoid secretion rate and adrenal blood flow were not strongly coupled. However, at one extreme of blood flow (close to zero) and at the opposite extreme (very high blood flow stimulated by adrenocorticotropic hormone) adrenal blood flow and cortisol secretion were tightly coupled. In the normal physiological range, the multiperiodic, rhythmic organization of circulatory variables and adrenal glucocorticoid function arises from independent or only weakly coupled oscillators, not necessarily harmonically related, manifesting near-periodicity with wobble and intermittency.

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