Laser-Doppler flowmetry reveals rapid perfusion changes in adipose tissue of lean and obese females

2006 ◽  
Vol 291 (5) ◽  
pp. E1025-E1030 ◽  
Author(s):  
P. Wellhöner ◽  
D. Rolle ◽  
P. Lönnroth ◽  
L. Strindberg ◽  
M. Elam ◽  
...  
Keyword(s):  
Blood Flow ◽  
Adipose Tissue ◽  
Laser Doppler Flowmetry ◽  
Laser Doppler ◽  
Whole Body ◽  
Tissue Blood Flow ◽  
Flow Measurements ◽  
Doppler Flowmetry ◽  
Reflex Responses ◽  
Obese Subjects

The present study aimed to evaluate adipose tissue blood flow (ATBF) by means of laser-Doppler flowmetry (LDF) in humans. Lower body negative pressure (LBNP) and straining known to affect epidermal blood flow through the autonomic nervous system were performed in 11 lean and 11 obese female volunteers. ATBF changes were compared between both groups and also discriminated from skin blood flow (SBF) responses of the immediate vicinity. Additionally, LDF measurements were compared with flow measurements using 133xenon washout in 10 lean subjects during whole body cooling. LDF estimations of SBF and ATBF showed a positive correlation to 133Xe during cooling. SBF and ATBF were reduced to the same extent in both lean and obese subjects during LBNP. Straining induced divergent changes in SBF and ATBF: initially SBF decreased while ATBF increased, but toward the end of straining SBF increased above baseline and ATBF returned down to baseline level. Those changes were similar in both weight groups. Interestingly, only in obese subjects, both LBNP and straining were followed by ATBF augmentation, while SBF levels remained stable. In conclusion, LDF compares with 133Xe washout in monitoring ATBF during tonic perfusion changes. Its strength, however, lies in the detection of rapid flow alterations within the subcutaneous tissue, allowing the evaluation of reflex responses of the subcutaneous microcirculation. Interestingly, those rapid changes in SBF and ATBF can be both concordant and discordant. With regard to ATBF, vasoconstrictor components of the reflex responses were similar in lean and obese subjects, whereas vasodilatory responses were more pronounced in obese volunteers.

scholarly journals Evaluation of the marginal gingival health using laser doppler flowmetry

2006 ◽  
Vol 17 (3) ◽  
pp. 219-222 ◽  
Author(s):  
Hakan Develioglu ◽  
Bülent Kesim ◽  
Aykut Tuncel
Keyword(s):  
Blood Flow ◽  
Laser Doppler Flowmetry ◽  
Laser Doppler ◽  
Plaque Index ◽  
Tissue Blood Flow ◽  
Doppler Flowmetry ◽  
Gingival Health ◽  
Significant Difference ◽  
Clinical Indices ◽  
And Control

The purposes of this study were to compare the gingival blood flow (GBF) in test sites (teeth retaining fixed partial dentures) and control sites (contralateral natural teeth) and investigate whether there is any relationship between clinical indices and GBF values. Twelve healthy subjects (6 females and 6 males) aged 20 to 54 years were enrolled this study. The GBF was measured from the middle point of the marginal gingiva in the test and control sites using laser Doppler flowmetry (LDF). Additionally, plaque index, gingival index and probing depth measurements were recorded. Statistically significant difference (p<0.05) was found between the test and control sites for marginal GBF. In contrast, no significant difference (p>0.05) was found between test and control sites with respect to the clinical indices, except for plaque index. The findings of this study suggest that there is a significant relation between resin-bonded fixed partial dentures with margins located subgingivally and marginal GBF. Clinical indices are helpful to collect information about the clinical health status of gingival tissues, but GBF is a good tool to measure gingival tissue blood flow and assess periodontal health. In conclusion, laser Doppler flowmetry can be used together with clinical indices to evaluate the marginal gingival health.

The use of laser Doppler flowmetry to evaluate oral soft tissue blood flow in humans: A review

2018 ◽  
Vol 86 ◽  
pp. 58-71 ◽  
Author(s):  
Ayepa Alain Kouadio ◽  
Fabienne Jordana ◽  
N’goran Justin Koffi ◽  
Pierre Le Bars ◽  
Assem Soueidan
Keyword(s):  
Blood Flow ◽  
Soft Tissue ◽  
Laser Doppler Flowmetry ◽  
Laser Doppler ◽  
Tissue Blood Flow ◽  
Doppler Flowmetry ◽  
Oral Soft Tissue

Validation of laser-Doppler flowmetry in measurement of spinal cord blood flow

1989 ◽  
Vol 257 (2) ◽  
pp. H674-H680 ◽  
Author(s):  
P. J. Lindsberg ◽  
J. T. O'Neill ◽  
I. A. Paakkari ◽  
J. M. Hallenbeck ◽  
G. Feuerstein
Keyword(s):  
Spinal Cord ◽  
Blood Flow ◽  
Cord Blood ◽  
Laser Doppler Flowmetry ◽  
Laser Doppler ◽  
Microvascular Blood Flow ◽  
Base Line ◽  
Spinal Cord Blood Flow ◽  
Flow Measurements ◽  
Doppler Flowmetry

Laser-Doppler flowmetry (LDF) is a non-invasive method for continuous on-line monitoring of microvascular blood flow. LDF has previously been validated with established methods in various tissues, yet its validity and resolution in the central nervous system (CNS) remain unclear. We compared LDF with the microsphere method (MS) using two independent laser probes placed on the dorsal lumbar spinal cord (L5 laminectomy) of anesthetized rabbits (n = 9). After base-line flow measurements, spinal cord blood flow (SCBF) was increased (up to 50%) with phenylephrine (10-80 micrograms.kg-1.min-1 iv) and decreased (up to 50%) with chlorisondamine (10 mg/kg iv) or other stimuli. The percentage changes of lumbar SCBF and vascular resistance (VR) from the base line obtained by LDF and MS excellently agreed (rBF = 0.86, rVR = 0.94, P less than 0.0001). LDF estimated also the absolute SCBF values parallel to MS (r = 0.77, P less than 0.001). In conclusion, the validity of LDF in estimating the SCBF and dynamic changes of BF and VR is confirmed. Therefore, LDF may prove useful for monitoring CNS microcirculation in normal or pathophysiological states.

Relative Importance of Flow versus  Pressure in Splanchnic Perfusion during Cardiopulmonary Bypass in Rabbits

2000 ◽  
Vol 92 (2) ◽  
pp. 457-457 ◽  
Author(s):  
Olivier Bastien ◽  
Vincent Piriou ◽  
Abdellah Aouifi ◽  
Claire Flamens ◽  
Rhys Evans ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cardiopulmonary Bypass ◽  
Laser Doppler Flowmetry ◽  
Laser Doppler ◽  
Analysis Of Covariance ◽  
Tissue Blood Flow ◽  
Splanchnic Perfusion ◽  
Doppler Flowmetry ◽  
Significant Difference ◽  
Splanchnic Ischemia

Background Decreased gastrointestinal perfusion has been reported during cardiopulmonary bypass (CPB). Conflicting results have been published concerning thresholds of pressure and flow to avoid splanchnic ischemia during CPB. This study compared splanchnic perfusion during independent and randomized variations of CPB pump flow or arterial pressure. Methods Ten rabbits were studied during mild hypothermic (36 degrees C) nonpulsatile CPB using neonatal oxygenators. Simultaneous measurements of tissue blood flow in four different splanchnic areas (gastric, jejunum, ileum, and liver) were performed by laser Doppler flowmetry (LDF) before CPB (T0) and during a 4-step factorial experimental block design. Pressure and flow were alternatively high or low in random order. Results Laser Doppler flowmetry was significantly lower than pre-CPB value but was better preserved (analysis of covariance) in all organs, except liver, when CPB flow was high, whatever the pressure. Splanchnic LDF values in the low- versus high-flow groups expressed as perfusion unit were (mean +/- SD): stomach, 94+/-66 versus 137+/-75; jejunum, 118+/-78 versus 172+/-75; ileum, 95+/-72 versus 146+/-83; and liver, 79+/-72 versus 108+/-118. No significant difference of LDF was observed between the high- and low-pressure groups, whatever the flow, except for liver: stomach, 115+/-64 versus 117+/-83; jejunum, 141+/-80 versus 148+/-83; ileum, 127+/-87 versus 114+/-76; liver, 114+/-88 versus 73+/-70. Conclusion Prevention of splanchnic ischemia during CPB should focus on preservation of high CPB blood flow rather than on high pressure.

Nitric oxide and receptors for VIP and PACAP in cutaneous active vasodilation during heat stress in humans

2012 ◽  
Vol 113 (10) ◽  
pp. 1512-1518 ◽  
Author(s):  
Dean L. Kellogg ◽  
Joan L. Zhao ◽  
Yubo Wu ◽  
John M. Johnson
Keyword(s):  
Nitric Oxide ◽  
Blood Flow ◽  
Heat Stress ◽  
Laser Doppler Flowmetry ◽  
Combined Treatment ◽  
Receptor Activation ◽  
Laser Doppler ◽  
Whole Body ◽  
Pac1 Receptor ◽  
Doppler Flowmetry

VPAC2 receptors sensitive to vasoactive intestinal polypeptide (VIP) and pituitary adenylyl cyclase activating polypeptide (PACAP), PAC1 receptors sensitive to PACAP, and nitric oxide (NO) generation by NO synthase (NOS) are all implicated in cutaneous active vasodilation (AVD) through incompletely defined mechanisms. We hypothesized that VPAC2/PAC1 receptor activation and NO are synergistic and interdependent in AVD and tested our hypothesis by examining the effects of VPAC2/PAC1 receptor blockade with and without NOS inhibition during heat stress. The VPAC2/PAC1 antagonist, pituitary adenylate cyclase activating peptide 6–38 (PACAP6–38) and the NOS inhibitor, NG-nitro-l-arginine methyl ester (l-NAME) were administered by intradermal microdialysis. PACAP6–38, l-NAME, a combination of PACAP6–38 and l-NAME, or Ringer's solution alone were perfused at four separate sites. Skin blood flow was monitored by laser-Doppler flowmetry at each site. Body temperature was controlled with water-perfused suits. Blood pressure was monitored by Finapres, and cutaneous vascular conductance (CVC) calculated (CVC = laser-Doppler flowmetry/mean arterial pressure). The protocol began with a 5- to 10-min baseline period without antagonist perfusion, followed by perfusion of PACAP6–38, l-NAME, or combined PACAP6–38 and l-NAME at the different sites in normothermia (45 min), followed by 3 min of whole body cooling. Whole body heating was then performed to induce heat stress and activate AVD. Finally, 58 mM sodium nitroprusside were perfused at all sites to effect maximal vasodilation for normalization of blood flow data. No significant differences in CVC (normalized to maximum) were found among Ringer's PACAP6–38, l-NAME, or combined antagonist sites during normothermia ( P > 0.05 among sites) or cold stress ( P > 0.05 among sites). CVC responses at all treated sites were attenuated during AVD ( P < 0.05 vs. Ringer's). Attenuation was greater at l-NAME and combined PACAP6–38- and l-NAME-treated sites than at PACAP6–38 sites ( P > 0.05). Because responses did not differ between l-NAME and combined treatment sites ( P > 0.05), we conclude that VPAC2/PAC1 receptors require NO in series to effect AVD.

scholarly journals Experimental and Clinical Evaluation of Capsular and Parenchymal Total Liver Perfusion

HPB Surgery ◽  
1992 ◽  
Vol 6 (2) ◽  
pp. 99-104 ◽  
Author(s):  
Katerina Kotzampassi ◽  
Efthimios Eleftheriadis ◽  
Homeros Aletras
Keyword(s):  
Blood Flow ◽  
Laser Doppler Flowmetry ◽  
Liver Perfusion ◽  
Liver Blood Flow ◽  
Laser Doppler ◽  
Biliary Surgery ◽  
Flow Measurements ◽  
Doppler Flowmetry ◽  
Total Liver ◽  
Liver Surface

Liver blood flow measurements obtained from both the liver surface and deep within the parenchyma, were correlated in an effort to assess the usefulness of laser-Doppler flowmetry for non-invasive monitoring of total liver blood flow, the probe being positioned on either the surface or within the liver parenchyma.In 23 Wistar rats and 10 biliary surgery patients, anaesthetized prior to gallbladder removal, liver microcirculation was measured at 4 points on the capsular surface, and consequently at 4 points deep within the parenchyma, using probes connected to a laser-Doppler flowmeter. The findings revealed that laser-Doppler measurements on the liver surface and within the parenchyma were well correlated, as no statistically significant differences were found either in rats or humans. It is concluded that laser- Doppler flowmetry for monitoring of total liver perfusion can be applied either on the capsular surface or within the hepatic parenchyma.

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