In Vivo Microvascular Oxygen Measurements by Phosphorescence Quenching Technique

2006 ◽  
Author(s):  
M. Shibata ◽  
S. Ichioka
Keyword(s):  
Phosphorescence Quenching ◽  
Oxygen Measurements

Intravascular oxygen distribution in subcutaneous 9L tumors and radiation sensitivity

1997 ◽  
Vol 82 (6) ◽  
pp. 1939-1945 ◽  
Author(s):  
George J. Cerniglia ◽  
David F. Wilson ◽  
Marek Pawlowski ◽  
Sergei Vinogradov ◽  
John Biaglow
Keyword(s):  
Tumor Vasculature ◽  
Radiation Sensitivity ◽  
Surrounding Tissue ◽  
Oxygen Distribution ◽  
Tissue Oxygen ◽  
Phosphorescence Quenching ◽  
Tumor Identification ◽  
Oxygen Measurements

Cerniglia, George J., David F. Wilson, Marek Pawlowski, Sergei Vinogradov, and John Biaglow. Intravascular oxygen distribution in subcutaneous 9L tumors and radiation sensitivity. J. Appl. Physiol. 82(6): 1939–1945, 1997.—Phosphorescence quenching was evaluated as a technique for measuring [Formula: see text] in tumors and for determining the effect of increased[Formula: see text] on sensitivity of the tumors to radiation. Suspensions of cultured 9L cells or small pieces of solid tumors from 9L cells were injected subcutaneously on the hindquarter of rats, and tumors were grown to between 0.2 and 1.0 cm in diameter. Oxygen-dependent quenching of the phosphorescence of intravenously injected Pd-meso-tetra-(4-carboxyphenyl) porphine was used to image the in vivo distribution of [Formula: see text] in the vasculature of small tumors and surrounding tissue. Maps (512 × 480 pixels) of tissue oxygen distribution showed that the[Formula: see text] within 9L tumors was low (2–12 Torr) relative to the surrounding muscle tissue (20–40 Torr). When the rats were given 100% oxygen or carbogen (95% O2-5% CO2) to breathe, the[Formula: see text] in the tumors increased significantly. This increase was variable among tumors and was greater with carbogen compared with 100% oxygen. Based on irradiation and regrowth studies, carbogen breathing increased the sensitivity of the tumors to radiation. This is consistent with the measured increase in[Formula: see text] in the tumor vasculature. It is concluded that phosphorescence quenching can be used for noninvasive determination of the oxygenation of tumors. This method for oxygen measurements has great potential for clinical application in tumor identification and therapy.

Monitoring the Dynamics of Tissue Oxygenation in Vivo by Phosphorescence Quenching

2003 ◽  
pp. 1-5 ◽  
Author(s):  
David F. Wilson ◽  
Sergei A. Vinogradov ◽  
Vladimir Rozhkov ◽  
Jennifer Creed ◽  
Ivo Rietveld ◽  
...  
Keyword(s):  
Tissue Oxygenation ◽  
Phosphorescence Quenching

scholarly journals Effects of aging and exercise training on spinotrapezius muscle microvascular Po2 dynamics and vasomotor control

2011 ◽  
Vol 110 (3) ◽  
pp. 695-704 ◽  
Author(s):  
Danielle J. McCullough ◽  
Robert T. Davis ◽  
James M. Dominguez ◽  
John N. Stabley ◽  
Christian S. Bruells ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Blood Flow ◽  
Exercise Training ◽  
Sodium Nitroprusside ◽  
Vascular Function ◽  
Treadmill Running ◽  
Aged Rats ◽  
Phosphorescence Quenching

With advancing age, there is a reduction in exercise tolerance, resulting, in part, from a perturbed ability to match O2 delivery to uptake within skeletal muscle. In the spinotrapezius muscle (which is not recruited during incline treadmill running) of aged rats, we tested the hypotheses that exercise training will 1) improve the matching of O2 delivery to O2 uptake, evidenced through improved microvascular Po2 (PmO2), at rest and throughout the contractions transient; and 2) enhance endothelium-dependent vasodilation in first-order arterioles. Young (Y, ∼6 mo) and aged (O, >24 mo) Fischer 344 rats were assigned to control sedentary (YSED; n = 16, and OSED; n = 15) or exercise-trained (YET; n = 14, and OET; n = 13) groups. Spinotrapezius blood flow (via radiolabeled microspheres) was measured at rest and during exercise. Phosphorescence quenching was used to quantify PmO2 in vivo at rest and across the rest-to-twitch contraction (1 Hz, 5 min) transition in the spinotrapezius muscle. In a follow-up study, vasomotor responses to endothelium-dependent (acetylcholine) and -independent (sodium nitroprusside) stimuli were investigated in vitro. Blood flow to the spinotrapezius did not increase above resting values during exercise in either young or aged groups. Exercise training increased the precontraction baseline PmO2 (OET 37.5 ± 3.9 vs. OSED 24.7 ± 3.6 Torr, P < 0.05); the end-contracting PmO2 and the time-delay before PmO2 fell in the aged group but did not affect these values in the young. Exercise training improved maximal vasodilation in aged rats to acetylcholine (OET 62 ± 16 vs. OSED 27 ± 16%) and to sodium nitroprusside in both young and aged rats. Endurance training of aged rats enhances the PmO2 in a nonrecruited skeletal muscle and is associated with improved vascular smooth muscle function. These data support the notion that improvements in vascular function with exercise training are not isolated to the recruited muscle.

New phosphorescence quenching oxygen measurements technique yields unusual tissue and plasma Po2 distributions

2007 ◽  
Vol 102 (5) ◽  
pp. 2081-2082 ◽  
Author(s):  
Amy G. Tsai ◽  
Pedro Cabrales ◽  
Paul C. Johnson ◽  
Marcos Intaglietta
Keyword(s):  
Phosphorescence Quenching ◽  
Oxygen Measurements

Po2 measurements in the microcirculation using phosphorescence quenching microscopy at high magnification

2008 ◽  
Vol 294 (6) ◽  
pp. H2905-H2916 ◽  
Author(s):  
Aleksander S. Golub ◽  
Roland N. Pittman
Keyword(s):  
Dominant Role ◽  
Phosphorescence Quenching ◽  
Flash Rate ◽  
Proposed Model ◽  
Stationary Tissue ◽  
Arteriolar Wall ◽  
High Respiration Rate ◽  
Flowing Blood ◽  
Reported Data ◽  
Oxygen Measurements

In phosphorescence quenching microscopy (PQM), the multiple excitation of a reference volume produces the integration of oxygen consumption artifacts caused by individual flashes. We analyzed the performance of two types of PQM instruments to explain reported data on Po2 in the microcirculation. The combination of a large excitation area (LEA) and high flash rate produces a large oxygen photoconsumption artifact manifested differently in stationary and flowing fluids. A LEA instrument strongly depresses Po2 in a motionless tissue, but less in flowing blood, creating an apparent transmural Po2 drop in arterioles. The proposed model explains the mechanisms responsible for producing apparent transmural and longitudinal Po2 gradients in arterioles, a Po2 rise in venules, a hypothetical high respiration rate in the arteriolar wall and mesenteric tissue, a low Po2 in lymphatic microvessels, and both low and uniform tissue Po2. This alternative explanation for reported paradoxical results of Po2 distribution in the microcirculation obviates the need to revise the dominant role of capillaries in oxygen transport to tissue. Finding a way to eliminate the photoconsumption artifact is crucial for accurate microscopic oxygen measurements in microvascular networks and tissue. The PQM technique that employs a small excitation area (SEA) together with a low flash rate was specially designed to avoid accumulated oxygen photoconsumption in flowing blood and lymph. The related scanning SEA instrument provides artifact-free Po2 measurements in stationary tissue and motionless fluids. Thus the SEA technique significantly improves the accuracy of microscopic Po2 measurements in the microcirculation using the PQM.

Nitric oxide modulates oxygen consumption by arteriolar walls in rat skeletal muscle

2005 ◽  
Vol 289 (6) ◽  
pp. H2673-H2679 ◽  
Author(s):  
Masahiro Shibata ◽  
Shigeru Ichioka ◽  
Akira Kamiya
Keyword(s):  
Nitric Oxide ◽  
Oxygen Consumption ◽  
Oxygen Consumption Rate ◽  
Consumption Rate ◽  
Phosphorescence Quenching ◽  
Arterial Blood ◽  
No Release ◽  
Vessel Walls

To study the role of nitric oxide (NO) in regulating oxygen consumption by vessel walls, the oxygen consumption rate of arteriolar walls in rat cremaster muscle was measured in vivo during flow-induced vasodilation and after inhibiting NO synthesis. The oxygen consumption rate of arteriolar walls was calculated based on the intra- and perivascular Po2 values measured by phosphorescence quenching laser microscopy. The perivascular Po2 value of the arterioles during vasodilation was significantly higher than under control conditions, although the intravascular Po2 values under both conditions were approximately the same. Inhibition of NO synthesis, on the other hand, caused a significant increase in arterial blood pressure and a significant decrease in arteriolar diameter. Inhibition of NO synthesis also caused a significant decrease in both the intra- and perivascular Po2 values of the arterioles. Inhibition of NO synthesis increased the oxygen consumption rate of the vessel walls by 42%, whereas enhancement of flow-induced NO release decreased it by 34%. These results suggest that NO plays an important role not only as a regulator of peripheral vascular tone but also as a modulator of tissue oxygenation by reducing oxygen consumption by vessel walls. In addition, enhancement of NO release during exercise may facilitate efficient oxygen supply to the surrounding high metabolic tissue.

scholarly journals A pilot study of the dynamics of tissue oxygenation in vivo using time-resolved phosphorescence imaging

2021 ◽  
pp. 2142001
Author(s):  
Natalia Kazachkina ◽  
Julia Lymar ◽  
Vladislav Shcheslavskiy ◽  
Alexander Savitsky
Keyword(s):  
Solid Tumor ◽  
Single Photon ◽  
Photon Counting ◽  
Time Resolved ◽  
Phosphorescence Lifetime ◽  
Phosphorescence Quenching ◽  
Single Photon Counting ◽  
Normal Tissues ◽  
Phosphorescence Lifetime Imaging

Oxygenation of tissues plays an important role in the development and progression of tumor to treatment effects. Method of metalloporphyrines phosphorescence quenching by oxygen is one of the ways to measure dynamics of the oxygen concentration in the tissues by phosphorescence lifetime imaging of meso-tetra(sulfopheny1)tetrabenzoporphyrin Pd (II) (TBP) using the time-correlated single photon counting (TCSPC) method. It has been shown that phosphorescence lifetime of the sensor in S37 tumor in vivo varied in the range of 130 to 290 [Formula: see text]s after both topical and intravenous administration of TBP. It indicates that oxygen level in tumors was lower compared to normal tissues where TBP phosphorescence has not been detected. Phosphorescence lifetimes of TBP increased in the solid tumor and in the muscle after photodynamic therapy of solid tumor that demonstrates oxygen consumption during treatment and possibly stopping the blood flow and hence the oxygen supply to the tissues.

SU-E-T-292: In-Vivo Blood Oxygen Measurements Via Interstitial Fiber Optic Probe and Photoacoustic Imaging

2013 ◽  
Vol 40 (6Part15) ◽  
pp. 271-271
Author(s):  
D Campos ◽  
A Torres ◽  
M Lakshman ◽  
M Kissick ◽  
R Kimple ◽  
...  
Keyword(s):  
Fiber Optic ◽  
Photoacoustic Imaging ◽  
Blood Oxygen ◽  
Fiber Optic Probe ◽  
Optic Probe ◽  
Oxygen Measurements

Standard cochlear implants as electrochemical sensors: Intracochlear oxygen measurements in vivo

2021 ◽  
pp. 113859
Author(s):  
Andreas Weltin ◽  
Jochen Kieninger ◽  
Gerald A. Urban ◽  
Sarah Buchholz ◽  
Susan Arndt ◽  
...  
Keyword(s):  
Cochlear Implants ◽  
Electrochemical Sensors ◽  
Oxygen Measurements
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