Measurement of renal cortical and medullary blood flow by laser-Doppler spectroscopy in the rat

Stern, Michael D.; Bowen, Peter; Parma, R.; Osgood, Richard W.; Bowman, Robert L.; Stein, Janice Gross

doi:10.1152/ajprenal.1979.236.1.f80

Cited by 60 publications

(46 citation statements)

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“…One major advantage of laser Doppler flowmetry is the negligible influence of the transducer on the microvascular bed under study. The accuracy of laser Doppler flow measurements in comparison with electromagnetic flow probes [12], (photo-) plethysmography [13], capillaroscopy [14], and xenon washout technique [15] was reported.…”

Section: Measured Parameters and Data Pointsmentioning

confidence: 99%

Isolated circulatory response to intravenous administration of the ACE inhibitor enalaprilat.

Boldt

Knothe

Schindler

et al. 1994

Brit J Clinical Pharma

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The isolated vascular effects of intravenous administration of the angiotensin converting enzyme (ACE) inhibitor enalaprilat were investigated. Thirty male patients undergoing cardiopulmonary bypass (CPB) were studied. According to a randomized sequence, 0.04 mg kg‐1 enalaprilat (low‐dose, n = 10), 0.08 mg kg‐1 (high‐dose, n = 10) enalaprilat or saline solution as placebo (control group, n = 10) was given as an i.v. bolus during CPB. Changes in mean arterial pressure (MAP) and venous reservoir (RV) of the extracorporeal circulation were studied as indices of arterial resistance and venous capacitance. Mean arterial blood pressure (MAP) and peripheral vascular resistance (SVR) were significantly more reduced in the high‐dose enalaprilat group (MAP: ‐36 mm Hg after 9 min; SVR: ‐836 dyn s cm‐5) than in the low‐dose group (MAP: ‐13 mm Hg after 10 min). Volume of the reservoir (RV) decreased in both enalaprilat treated groups indicating additional (dose‐dependent) venous pooling effects of the substance (low‐dose: ‐ 300 ml; high‐dose: ‐520 ml; control group: ‐100 ml). Skin capillary blood flow measured by laser Doppler flowmetry (LDF) increased after injection of 0.04 mg kg‐1 enalaprilat, whereas it decreased significantly when MAP fell markedly in patients treated with high‐dose enalaprilat. I.v. enalaprilat had dose‐dependent vasodilating properties in the arterial and venous vessel system indicating reduction in pre‐ and afterload. Microcirculation in both enalaprilat treated groups improved as long as reduction in blood pressure was not limited.

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Section: Measured Parameters and Data Pointsmentioning

confidence: 99%

Isolated circulatory response to intravenous administration of the ACE inhibitor enalaprilat.

Boldt

Knothe

Schindler

et al. 1994

Brit J Clinical Pharma

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“…Studies performed by our laboratory (1,2) and others (3)(4)(5)(6)(7) have demonstrated a renal vasoconstrictor response to angiotensin II (All)' infusion resulting in decreases in renal blood flow and nephron filtration rate as well as a reduction in the glomerular ultrafiltration coefficient. A large amount of investigative effort has been expended in delineating the role ofthe renin-angiotensin system in the control ofglomerular ultrafiltration.…”

Section: Introductionmentioning

confidence: 99%

Changes in glomerular hemodynamic response to angiotensin II after subacute renal denervation in rats.

Tucker¹,

Mundy²,

Maciejewski³

et al. 1986

J. Clin. Invest.

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We examined the changes in glomerular hemodynamics produced by angiotensin II (AII) in both normal Munich-Wistar rats and rats which were unilaterally renal denervated (measured kidney) 4-6 d prior to the measurement periods. Measurements of glomerular dynamics were performed in a control period after plasma volume expansion and during infusion of 11 ng. 100 g body wt-1 * min-' of AI. The glomerular hydrostatic pressure gradient increased from 38±1 to 49±1 mmHg in denervated rats compared with a lesser response in controls (from 39±1 to 45±1 mmHg, P < 0.05). Single nephron plasma flow decreased from 213±17 to 87±4 nl * min-' g kidney wt (KW)-' in denervated kidneys versus a more modest decrease in control kidneys (from 161±9 to 102±5 nl* min * gKW-1). These changes were due to a greater increase in both afferent and efferent arteriolar resistance after AII infusion in denervated compared with control kidneys. Glmerular AII receptor maximum binding was 1,196±267 fmol/ mg protein in denervated kidneys compared with 612±89 fmol/ mg protein (P < 0.01) in controls with no change in receptor affinity. We conclude the subacute unilateral renal denervation (a) results in renal vasodilation, (b) denervation magnifies the vasoconstrictive effect of AII infusion on glomerular hemodynamics, and (c) the observed increased response to AII after denervation is associated with increases in glomerular AII receptors.

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“…This laser Doppler flowmetry has been shown to correlate well with many of the conventional methods used to assess peripheral blood flow (STERN et al, 1977(STERN et al, , 1979ENGELHART and KRISTENSEN,1983;LARRABEE et a!.,1983;SMITs et a!., 1986). However, we have observed previously that local heating of the hand from 37 to 41 ~C in a warm environment caused a reduction of finger blood flow when measured by venous occlusion plethysmography and, in contrast, a continued increase of finger blood flow when measured by laser Doppler flowmetry (PERIFLUX PF-ld) (NAGASAKA et a!., 1987).…”

Section: Discussionmentioning

confidence: 89%

Partitional measurements of circulation can be made between capillaries and arterovenous anastomoses in the human finger.

Nagasaka¹,

Hirata²,

Nunomura³

1988

Jpn.J.Physiol

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We compared the responses of finger blood flow to local and/or whole body warming, as measured by laser Doppler flowmetry (PERIFLUX PF-ld) (LDF), and by venous occlusion plethysmography (BF). The subject's hands were immersed in a bath of water whose temperature (TW) was initially set at 25°C. The tested hand was kept at about 10 cm above heart level to facilitate the drainage of finger veins during measurement. The ambient temperature (Ta) was initially 20 C. Then, measurements were made under the following conditions on separate days: 1) local hand warming ony (LHW), Tw was raised from 25 to 40°C; 2) whole body warming only (WBW), Ta was raised from 20 to 35°C; and 3) LHW and WBW combined (CW), LHW (TW was raised to 35°C and maintained) was followed by WBW. Results showed that both LHW and WBW increased LDF and BF. LDF signals correlated significantly with BF values in each condition (r = 0.932-0.955). However, the slope of the line showing the relationship of LDF and BF, determined by least squares linear regression analysis, was steeper in LHW than in WBW. In CW, the slope showed a bend, creating two different sections in the relationship. Below the bend the relation was steeper and showed a similar slope as that in LHW; above the bend, the relation was more gradual and a similar slope as that in WBW. No such bend was observed in measurements of the forearm skin in CW. The present results suggest that partitional measurements of circulation between AVA's and superficial vessels can be made in the finger by the simultaneous use of laser Doppler flowmetry and venous occlusion plethysmography. Local warming of the hand increases finger blood flow mainly through capillaries and subpapillary vessels and indirect whole body warming increases finger blood flow predominantly through deeply located vessels, presumably including AVA's.

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Measurement of renal cortical and medullary blood flow by laser-Doppler spectroscopy in the rat

Cited by 60 publications

References 0 publications

Isolated circulatory response to intravenous administration of the ACE inhibitor enalaprilat.

Isolated circulatory response to intravenous administration of the ACE inhibitor enalaprilat.

Changes in glomerular hemodynamic response to angiotensin II after subacute renal denervation in rats.

Partitional measurements of circulation can be made between capillaries and arterovenous anastomoses in the human finger.

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