Measurement of hepatocellular function, cardiac output, effective blood volume, and oxygen saturation in rats

The available techniques do not permit the measurement of hepatocellular function, cardiac output, effective blood volume, and oxygen saturation in small animals without the need of blood or tissue sampling. We present methodology that permits us to measure the above variables in the rat. Multiple doses of indocyanine green (ICG; 0.16-2.6 mg/kg) were given to pentobarbital-anesthetized rats, and [ICG] was continuously measured by an in vivo hemoreflectometer. Initial velocity of clearance (Vo) was determined from the [ICG] vs. time plot for each dose by nonlinear regression. The maximal velocity of clearance (Vmax; indicating hepatocellular function) was calculated. Vmax was 1) accurately determined using two, three, or four doses of ICG; 2) it was 1.09 +/- 0.16 mg.kg-1.min-1, not different from the Vo of the near-saturating dose of 25 mg/kg; and 3) it decreased after partial hepatectomy. Cardiac output was 41.89 +/- 1.46 ml.100 g-1.min-1, effective blood volume was 6.12 +/- 0.34 ml/100 g, and oxygen saturation was 92 +/- 2%. These methodologies may prove useful in the evaluation of hepatocellular dysfunction and hemodynamic parameters in the rat during and after various diseased states.

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Technique for Using Video Microscopy and Indicator Dilution for Repeated Measurements of Cardiac Output in Small Animals

Anesthesiology ◽

10.1097/00000542-200103000-00021 ◽

2001 ◽

Vol 94 (3) ◽

pp. 489-495 ◽

Cited By ~ 8

Author(s):

Richard J. Rivers ◽

Judy B. Beckman ◽

Mary D. S. Frame

Keyword(s):

Body Weight ◽

Cardiac Output ◽

Steady State ◽

Light Intensity ◽

Cardiac Index ◽

Blood Volume ◽

Video Microscopy ◽

Indicator Dilution ◽

Small Animals

Background The authors developed an indicator dilution technique for small animals to repeatedly determine cardiac output and blood volume without cardiac instrumentation or blood sampling. Methods Observations were made in the hamster (N = 32, 70 mg/kg pentobarbital) cremaster using in vivo fluorescence videomicroscopy. Fluorescein isothiocyanate-conjugated bovine serum albumin (10 mg/ml) was injected as a bolus dose (right jugular) while video recording the light intensity in a 20-microm arteriole (intensified charge-coupled device [CCD] camera at fixed gain). The intensity signal was analyzed over time (background subtracted) and calibrated to the dye concentration. The ex vivo calibration was performed using a constant optical path length (20 microm) and a range of dye and hematocrit concentrations. In vivo tube hematocrit was determined using standard methods with fluorescently labeled erythrocytes. Thus, quenching of the fluorescence signal by hemoglobin was corrected for the calibration, and the plasma space in the arteriole was determined. The steady state dye concentration measured by the light intensity at 2 min was not different from the dye concentration found by direct spectrophotometric analysis of the plasma. Results Cardiac index was calculated as milliliters of blood per minute per kilogram body weight. The calculated cardiac index was 359 +/- 18 ml.min(-1).kg(-1), which is not different from the reported values for hamsters. Cardiac output was increased twofold when enough intravenous nitroprusside or nitroglycerine was injected to decrease mean arterial pressure from 90 to 70 mmHg. Cardiac output was elevated during dobutamine infusion (16 microg.kg(-1).min(-1)) and decreased during esmolol infusion (50, 75.kg(-1).min(-1)). Blood volume determined from the steady state dye concentrations was 6.2 +/- 0.5 ml/100 g body weight, within the normal range for hamsters. Conclusions Fluorescent dye dilution and video microscopy can be used to repeatedly determine cardiac output or blood volume in small animals.

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Influence of red laser irradiation on hemoglobin oxygen saturation and blood volume in human skin in vivo

10.1117/12.434687 ◽

2001 ◽

Cited By ~ 4

Author(s):

Alexander A. Stratonnikov ◽

Natalia V. Ermishova ◽

Victor B. Loschenov

Keyword(s):

Oxygen Saturation ◽

Laser Irradiation ◽

Human Skin ◽

Blood Volume ◽

Hemoglobin Oxygen Saturation

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Non-Invasive Monitoring of Hemodynamic Parameters during Hemodialysis

The International Journal of Artificial Organs ◽

10.1177/039139889501800904 ◽

1995 ◽

Vol 18 (9) ◽

pp. 499-503 ◽

Cited By ~ 4

Author(s):

F. Pizzarelli ◽

P. Dattolo ◽

M. Piacenti ◽

M.A. Morales ◽

T. Cerrai ◽

...

Keyword(s):

Blood Pressure ◽

Cardiac Output ◽

Blood Volume ◽

Impedance Cardiography ◽

Hemodynamic Parameters ◽

Non Invasive ◽

Transthoracic Impedance ◽

Cardiac Output Index ◽

On Line ◽

Two Parameters

We studied in 13 hemodialysis patients intradialytic variations of blood volume (BV) and cardiac output, by means of non-invasive methods. We found a weak correlation, r 0.2 or less, between BV variations and intradialysis blood pressure variations. The sensitivity of the former in describing the variations of the latter was only 32%. During the 30 min preceeding the hypotensive crisis the percent BV variations did not show any predictive trend. On the contrary, refilling increased as blood pressure dropped and a weak inverse relation (r -0.35) was found between these two parameters. Unstable patients had predialytic blood volume values significantly lower than stable ones and comparable to healthy subjects. On the contrary, the correlation between percent variations of cardiac output index and MAP was 0.68 with a sensitivity and specificity of 90% and 59%, respectively. Unfortunately these promising results were obtained only with an estimate of cardiac output obtained by echocardiography and not by transthoracic impedance cardiography, which is much more feasible than the former as on-line monitoring of cardiac output. On-line monitoring of hemodynamic parameters is an appealing but still unsolved task.

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Determination of in vivo Blood Oxygen Saturation and Blood Volume Fraction Using Diffuse Reflectance Spectroscopy

IFMBE Proceedings - 26th Southern Biomedical Engineering Conference SBEC 2010, April 30 - May 2, 2010, College Park, Maryland, USA ◽

10.1007/978-3-642-14998-6_86 ◽

2010 ◽

pp. 336-339

Author(s):

P. Chen ◽

W. Lin

Keyword(s):

Oxygen Saturation ◽

Blood Volume ◽

Diffuse Reflectance ◽

Volume Fraction ◽

Diffuse Reflectance Spectroscopy ◽

Reflectance Spectroscopy ◽

Blood Oxygen ◽

Blood Oxygen Saturation

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Effects of different duration contractions on elasticity, blood volume, and oxygen saturation of human tendon in vivo

European Journal of Applied Physiology ◽

10.1007/s00421-009-1037-2 ◽

2009 ◽

Vol 106 (3) ◽

pp. 445-455 ◽

Cited By ~ 10

Author(s):

Keitaro Kubo ◽

Toshihiro Ikebukuro ◽

Katsutoshi Yaeshima ◽

Hiroaki Kanehisa

Keyword(s):

Oxygen Saturation ◽

Blood Volume ◽

Human Tendon

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Dynamic synchronization analysis of venous pressure-driven cardiac output in rainbow trout

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.00228.2003 ◽

2003 ◽

Vol 285 (4) ◽

pp. R889-R896 ◽

Cited By ~ 8

Author(s):

Adrienne Robyn Minerick ◽

Hsueh-Chia Chang ◽

Todd M. Hoagland ◽

Kenneth R. Olson

Keyword(s):

Cardiac Output ◽

Rainbow Trout ◽

Blood Volume ◽

Hilbert Transform ◽

Venous Pressure ◽

Time Lag ◽

Venous Compliance ◽

Pressure Transducers ◽

The Hilbert Transform

Measurement of venous function in vivo is inherently difficult. In this study, we used the Hilbert transform to examine the dynamic relationships between venous pressure and cardiac output (CO) in rainbow trout whose blood volume was continuously increased and decreased by ramp infusion and withdrawal (I/W). The dorsal aorta and ductus Cuvier were cannulated percutaneously and connected to pressure transducers; a flow probe was placed around the ventral aorta. Whole blood from a donor was then I/W via the dorsal aortic cannula at a rate of 10% of the estimated blood volume per minute, and the duration of I/W was varied from 40, 60, 80, 90, 120, 230, 240, 260, 300, and 340 s. Compliance [change in (Δ) blood vol/Δvenous pressure] was 2.8 ± 0.2 ml · mmHg-1 · g-1 ( N = 25 measurements; 6 fish with closed pericardium) and 2.8 ± 0.3 ml · mmHg-1 · kg-1 ( N = 19 measurements, 4 fish with open pericardium). Compliance was positively correlated with the duration of I/W, indicative of cardiovascular reflex responses at longer I/W durations. In trout with closed pericardium, CO followed venous pressure oscillations with an average time lag of 4.2 ± 1.0 s ( N = 9); heart rate (HR) was inversely correlated with CO. These studies show that CO is entrained by modulation of venous pressure, not by HR. Thus, although trout have a rigid pericardium, venous pressure (vis-a-tergo), not cardiac suction (vis-a-fronte), appears to be the primary determinant of CO. Estimation of venous compliance by ramp-modulation of venous pressure is faster and less traumatic than classical capacitance measurements and appears applicable to a variety of vertebrate species, as does the Hilbert transform, which permits analysis of signals with disparate frequencies.

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Determination in vivo of regional circulatory dynamics in intact intestine

American Journal of Physiology-Legacy Content ◽

10.1152/ajplegacy.1962.203.6.1094 ◽

1962 ◽

Vol 203 (6) ◽

pp. 1094-1102 ◽

Cited By ~ 5

Author(s):

Marvin B. Bacaner ◽

Myron Pollycove

Keyword(s):

Blood Flow ◽

Cardiac Output ◽

Blood Volume ◽

Regional Blood Flow ◽

Human Subjects ◽

Beta Particle ◽

Blood Dilution ◽

Regional Blood Volume ◽

Circulatory Dynamics

A radioisotope technique employing a specially designed and critically shielded detector positioned in the gut lumen is utilized to monitor in vivo beta particle radioactivity in the circulation. The short range of the P32 beta in tissue (0.8 mm half thickness) is suited for this procedure because, with appropriate shielding, detected activity is limited to that contained in the blood perfusing the intestine surrounding the counter, with adjacent loops excluded. Regional blood volume is calculated from the regional counting rate of circulating P32-labeled red blood cells; regional blood flow is estimated from the local blood dilution curve. The effects of a variety of experimental maneuvers on circulatory dynamics are presented. Acetylcholine decreases regional blood flow but increases regional blood volume while cardiac output is increased. In contrast, l-norepinephrine appears to decrease both regional blood flow and regional blood volume with cardiac output relatively unchanged. This technique can be used in human subjects to evaluate the relation of regional intestinal circulation to regional function and pathology.

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Effect of Exercise-Induced Reductions in Blood Volume on Cardiac Output and Oxygen Transport Capacity

Frontiers in Physiology ◽

10.3389/fphys.2021.679232 ◽

2021 ◽

Vol 12 ◽

Author(s):

Janis Schierbauer ◽

Torben Hoffmeister ◽

Gunnar Treff ◽

Nadine B. Wachsmuth ◽

Walter F. J. Schmidt

Keyword(s):

Cardiac Output ◽

Stroke Volume ◽

Oxygen Saturation ◽

Blood Volume ◽

Oxygen Transport ◽

Arterial Oxygen ◽

Peripheral Oxygen Saturation ◽

Heart Volume ◽

Arterial Oxygen Content ◽

Oxygen Transport Capacity

We wanted to demonstrate the relationship between blood volume, cardiac size, cardiac output and maximum oxygen uptake (V.O2max) and to quantify blood volume shifts during exercise and their impact on oxygen transport. Twenty-four healthy, non-smoking, heterogeneously trained male participants (27 ± 4.6 years) performed incremental cycle ergometer tests to determine V.O2max and changes in blood volume and cardiac output. Cardiac output was determined by an inert gas rebreathing procedure. Heart dimensions were determined by 3D echocardiography. Blood volume and hemoglobin mass were determined by using the optimized CO-rebreathing method. The V.O2max ranged between 47.5 and 74.1 mL⋅kg–1⋅min–1. Heart volume ranged between 7.7 and 17.9 mL⋅kg–1 and maximum cardiac output ranged between 252 and 434 mL⋅kg–1⋅min–1. The mean blood volume decreased by 8% (567 ± 187 mL, p = 0.001) until maximum exercise, leading to an increase in [Hb] by 1.3 ± 0.4 g⋅dL–1 while peripheral oxygen saturation decreased by 6.1 ± 2.4%. There were close correlations between resting blood volume and heart volume (r = 0.73, p = 0.002), maximum blood volume and maximum cardiac output (r = 0.68, p = 0.001), and maximum cardiac output and V.O2max (r = 0.76, p < 0.001). An increase in maximum blood volume by 1,000 mL was associated with an increase in maximum stroke volume by 25 mL and in maximum cardiac output by 3.5 L⋅min–1. In conclusion, blood volume markedly decreased until maximal exhaustion, potentially affecting the stroke volume response during exercise. Simultaneously, hemoconcentrations maintained the arterial oxygen content and compensated for the potential loss in maximum cardiac output. Therefore, a large blood volume at rest is an important factor for achieving a high cardiac output during exercise and blood volume shifts compensate for the decrease in peripheral oxygen saturation, thereby maintaining a high arteriovenous oxygen difference.

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