scholarly journals Cerebral metabolism, oxidation and inflammation in severe passive hyperthermia with and without respiratory alkalosis

2020 ◽  
Vol 598 (5) ◽  
pp. 943-954 ◽  
Author(s):  
Anthony R. Bain ◽  
Ryan L. Hoiland ◽  
Joseph Donnelly ◽  
Daniela Nowak‐Flück ◽  
Mypinder Sekhon ◽  
...  
Keyword(s):  
Cerebral Metabolism ◽  
Respiratory Alkalosis ◽  
Passive Hyperthermia

Lactate and Pyruvate Levels in Brain and Skeletal Muscle During Hyperthermia in Dogs

1971 ◽  
Vol 49 (6) ◽  
pp. 520-524 ◽  
Author(s):  
Robert B. Dunn ◽  
Franco Lioy
Keyword(s):  
Cerebrospinal Fluid ◽  
Cerebral Metabolism ◽  
Free Breathing ◽  
Respiratory Alkalosis ◽  
Tissue Hypoxia ◽  
Sagittal Sinus ◽  
Arterial Blood ◽  
Arterial Ph ◽  
Anesthetized Dogs ◽  
Lactate And Pyruvate

Tissue hypoxia, as shown by an increase of the arterial concentration of lactate and of the lactate–pyruvate (L/P) ratio, has been observed during hyperthermia in free-breathing animals with high arterial [Formula: see text]. The effect of raising body temperature to 41.9 °C for 2 h on lactate and pyruvate concentrations in arterial, muscle venous, and sagittal sinus blood and cerebrospinal fluid was studied in anesthetized dogs. The animals were paralyzed with gallamine, and arterial pH and [Formula: see text] maintained at normal levels by artificial ventilation with 50% O2[Formula: see text]. A slight increase in lactate and pyruvate took place in the arterial blood and parallel changes were observed both in the muscle venous and sagittal sinus blood. The L/P ratio did not change. Lactate and pyruvate increased markedly in the CSF, without a change in the L/P ratio. Therefore hyperthermia, in the absence of respiratory alkalosis, does not appear to induce tissue hypoxia associated with an increase in L/P ratio. The lack of correlation between lactate and pyruvate concentrations in sagittal sinus blood and cerebrospinal fluid confirms the fact that the A–V differences of these substrates across the brain are not a good index of cerebral metabolism.

Cerebral metabolism in patients with intracranial tumors

1972 ◽  
Vol 36 (4) ◽  
pp. 451-462 ◽  
Author(s):  
Rein Zupping
Keyword(s):  
Metabolic Acidosis ◽  
Cerebral Metabolism ◽  
Brain Lesion ◽  
Clinical Signs ◽  
Sodium Concentration ◽  
Respiratory Alkalosis ◽  
Intracranial Tumors ◽  
Acid Base ◽  
Content Type ◽  
Close Relationship

✓ In a series of 64 patients with various intracranial tumors the cerebrospinal fluid (CSF), arterial and jugular venous acid-base, gas, and electrolyte values were measured before surgery and during the first 8 postoperative days. Before operation, patients without clinical signs of increased intracranial pressure had almost normal CSF acid-base status and cerebral gas exchange. The patients with signs of intracranial hypertension had CSF metabolic acidosis, arterial and jugular venous respiratory alkalosis, and mild arterial and jugular hypoxemia. Following surgery a remarkable increase in CSF metabolic acidosis, arterial and jugular hypocapnia, and hypoxemia occurred. A slight decrease of CSF potassium concentration was also revealed but the CSF sodium concentration was found to be elevated only in fatal cases or in patients with impaired consciousness. A close relationship was found between the severity of brain damage and the degree of CSF metabolic acidosis and arterial hypocapnia. Cerebral venous hypoxemia was not related to the severity of the brain lesion. It is suggested that cerebral acidosis may contribute to the development of brain edema and pulmonary hyperventilation in patients with intracranial tumors.

2D NMR studies on muscle and cerebral metabolism in vivo

1994 ◽  
Vol 91 ◽  
pp. 697-703 ◽  
Author(s):  
B Gillet ◽  
BT Doan ◽  
C Verre-Sebrie ◽  
O Fedeli ◽  
JC Beloeil ◽  
...  
Keyword(s):  
Cerebral Metabolism ◽  
2D Nmr ◽  
Nmr Studies

scholarly journals The use of the standard exercise test to establish the clinical significance of mild echocardiographic changes in a Thoroughbred poor performer : clinical communication

2004 ◽  
Vol 75 (2) ◽  
Author(s):  
C. Meyer ◽  
R. Gerber ◽  
A.J. Guthrie
Keyword(s):  
Exercise Test ◽  
Poor Performance ◽  
Respiratory Alkalosis ◽  
Mitral Valve Insufficiency ◽  
Cardiac Insufficiency ◽  
Strenuous Exercise ◽  
Clinical Communication ◽  
Valve Insufficiency ◽  
Blood Gas Analyses ◽  
Work Up

A 4-year-old Thoroughbred gelding racehorse was referred to the Onderstepoort Veterinary Academic Hospital (OVAH) with a history of post-race distress and collapse. In the absence of any obvious abnormalities in the preceding diagnostic work-up, a standard exercise test was performed to determine an underlying cause for the post-race distress reported. In this particular case oxygen desaturation became evident at speeds as slow as 6 m/s, where PO2 was measured at 82.3 mm Hg. Similarly at a blood pH of 7.28, PCO2 had dropped to 30.0mm Hg indicating a combined metabolic acidosis and respiratory alkalosis. The cause of the distress was attributed to a severe hypoxia, with an associated hypocapnoea, confirmed on blood gas analyses, where PO2 levels obtained were as low as 56.6 mm Hg with a mean PCO2 level of 25.4 mm Hg during strenuous exercise. Arterial oxygenation returned to normal immediately after cessation of exercise to 106.44 mm Hg, while the hypocapnoeic alkalosis, PCO2 25.67 mm Hg, persisted until the animal's breathing normalized. The results obtained were indicative of a dynamic cardiac insufficiency present during exercise. The combination of an aortic stenosis and a mitral valve insufficiency may have resulted in a condition similar to that described as high-altitude pulmonary oedema, with respiratory changes and compensation as for acute altitude disease. The results obtained were indicative of a dynamic cardiac insufficiency present during exercise and substantiate the fact that an extensive diagnostic regime may be required to establish a cause for poor performance and that the standard exercise test remains an integral part of this work-up.

Cerebral Metabolism and EEG During Combination of Hypocapnia and Isoflurane-induced Hypotension in Dogs

1986 ◽  
Vol 65 (6) ◽  
pp. 602-608 ◽  
Author(s):  
Alan A. Artru
Keyword(s):  
Cerebral Metabolism ◽  
Induced Hypotension

scholarly journals 216 Thermoregulatory and physiological responses of sows at different reproductive stages exposed to increasing ambient temperature

2020 ◽  
Vol 98 (Supplement_3) ◽  
pp. 7-7
Author(s):  
Betty R McConn ◽  
Alan W Duttlinger ◽  
Kouassi R Kpodo ◽  
Jacob M Maskal ◽  
Brianna N Gaskill ◽  
...  
Keyword(s):  
Heat Stress ◽  
Ambient Temperature ◽  
Physiological Responses ◽  
Blood Gases ◽  
Respiratory Alkalosis ◽  
Stress Sensitivity ◽  
Late Gestation ◽  
Acid Base Balance ◽  
Study Objective ◽  
Cell Counts

Abstract Pregnant sows, especially during late-gestation, may be susceptible to heat stress due to increased metabolic heat production and body mass. Therefore, the study objective was to determine the thermoregulatory and physiological responses of sows exposed to increasing ambient temperature (TA) at 3 reproductive stages. In 3 repetitions, 27 multiparous sows (parity 3.22±0.89) were individually housed and had jugular catheters placed 5.0±1.0 d prior to the experiment. To differentiate between reproductive stages, sows were categorized as open (not pregnant, n=9), mid-gestation (59.7±9.6 days pregnant, n=9), or late-gestation (99.0±4.8 days pregnant, n=9). During the experiment, sows were exposed to 6 consecutive 1 h periods of increasing TA (period 1, 14.39±2.14°C; period 2, 16.20±1.39°C; period 3, 22.09±1.87°C; period 4, 26.34±1.39°C; period 5, 30.56±0.81°C; period 6, 35.07±0.96°C), with 1 h transition phases in between each period. Respiration rate (RR), heart rate (HR), skin temperature, and vaginal temperature (TV) were measured every 20 min and the mean was calculated for each period. At the end of each period, blood gases, leukocytes, and red blood cell counts were measured. Overall, RR and HR were greater (P≤0.04; 45.6% and 12.9%, respectively) in late-gestation versus mid-gestation sows. Compared to mid-gestation and open sows, TV tended to be greater (P=0.06) during period 4 (0.18°C and 0.29°C, respectively) and period 5 (0.14°C and 0.18°C, respectively) in late-gestation sows. Blood O2 increased (P< 0.01; 18.1%) for all sows with advancing period, regardless of reproductive stage. Late-gestation sows had reduced (P=0.02; 16.1%) blood CO2 compared to mid-gestation sows, regardless of period. In summary, late-gestation sows appear to be more sensitive to increasing TA as indicated by increased RR, HR, TV, and blood O2, and reduced blood CO2 when compared to mid-gestation or open sows. This change in O2 and CO2, due to increasing RR and heat stress sensitivity of late-gestation sows, may suggest an alteration to the acid-base balance, leading to respiratory alkalosis.

scholarly journals Curbing action potential generation or ATP-synthase leads to a decrease in in-cell pyruvate dehydrogenase activity in rat cerebrum slices

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Benjamin Grieb ◽  
Sivaranjan Uppala ◽  
Gal Sapir ◽  
David Shaul ◽  
J. Moshe Gomori ◽  
...  
Keyword(s):  
Action Potential ◽  
Atp Synthase ◽  
Neural Activity ◽  
Pyruvate Dehydrogenase ◽  
Cerebral Metabolism ◽  
Neuronal Firing ◽  
Action Potential Generation ◽  
Potential Generation ◽  
Drastic Increase ◽  
Rat Cerebrum

AbstractDirect and real-time monitoring of cerebral metabolism exploiting the drastic increase in sensitivity of hyperpolarized 13C-labeled metabolites holds the potential to report on neural activity via in-cell metabolic indicators. Here, we followed the metabolic consequences of curbing action potential generation and ATP-synthase in rat cerebrum slices, induced by tetrodotoxin and oligomycin, respectively. The results suggest that pyruvate dehydrogenase (PDH) activity in the cerebrum is 4.4-fold higher when neuronal firing is unperturbed. The PDH activity was 7.4-fold reduced in the presence of oligomycin, and served as a pharmacological control for testing the ability to determine changes to PDH activity in viable cerebrum slices. These findings may open a path towards utilization of PDH activity, observed by magnetic resonance of hyperpolarized 13C-labeled pyruvate, as a reporter of neural activity.

Respiratory Alkalosis Accompanying Ammonium Toxicity

1956 ◽  
Vol 9 (3) ◽  
pp. 367-370 ◽  
Author(s):  
Kathleen E. Roberts ◽  
F. Gregg Thompson ◽  
J. William Poppell ◽  
Parker Vanamee
Keyword(s):  
Respiratory Alkalosis ◽  
Ammonium Toxicity
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