scholarly journals On the suitability of laser-Doppler flowmetry for capturing microvascular blood flow dynamics from darkly pigmented skin

2019 ◽  
Vol 40 (7) ◽  
pp. 074005 ◽  
Author(s):  
Yunus A Abdulhameed ◽  
Gemma Lancaster ◽  
Peter V E McClintock ◽  
Aneta Stefanovska
Keyword(s):  
Blood Flow ◽  
Laser Doppler Flowmetry ◽  
Flow Dynamics ◽  
Laser Doppler ◽  
Microvascular Blood Flow ◽  
Doppler Flowmetry ◽  
Blood Flow Dynamics

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.

Role of nitric oxide in vasodilator response induced by salbutamol in rat diaphragmatic microcirculation

1997 ◽  
Vol 272 (5) ◽  
pp. H2173-H2179 ◽  
Author(s):  
H. Y. Chang
Keyword(s):  
Nitric Oxide ◽  
Blood Flow ◽  
Cyclic Amp ◽  
Laser Doppler Flowmetry ◽  
Ringer Solution ◽  
Laser Doppler ◽  
Microvascular Blood Flow ◽  
Doppler Flowmetry ◽  
Vasodilator Response

To determine the contribution of nitric oxide (NO) to the vasodilator response induced by salbutamol in diaphragmatic microcirculation, we studied a diaphragmatic preparation in anesthetized rats. With bicarbonate-buffered Ringer solution continuously suffusing the diaphragm, laser-Doppler flowmetry was used to record microvascular blood flow (QLDF). The drugs were applied to the surface of the diaphragm. Salbutamol (3.2 x 10(-7)-10(-4) M), isoproterenol (3.2 x 10(-8)-3.2 x 10(-6) M), and forskolin (3.2 x 10(-7)-10(-5) M) each elicited a concentration-dependent increase in QLDF. The vasodilator response induced by salbutamol (3.2 x 10(-7), 10(-6), and 3.2 x 10(-6) M) was attenuated by a 15-min suffusion of N omega-nitro-L-arginine (L-NNA, 10(-4) M), and pretreatment with L-arginine (10(-2) M) could restore salbutamol-induced vasodilator responses. Salbutamol-induced vasodilation was also abolished by propranolol (10(-5) M). Similarly, the vasodilator response elicited by isoproterenol (3.2 x 10(-8), 10(-7), and 3.2 x 10(-7) M) and forskolin (3.2 x 10(-7), 10(-6), and 3.2 x 10(-6) M) was inhibited by L-NNA (10(-4) M). In contrast, the vasodilator response induced by adenosine (10(-6), 10(-5), and 10(-4) M) was not affected by L-NNA (10(-4) M). These data indicate that in rat diaphragmatic microcirculation salbutamol-induced vasodilation may be partly mediated by beta-adrenoceptors on the endothelium. Moreover, these data suggest that an elevation of cyclic AMP in the endothelium may cause release of NO.

New Means for Evaluation of Volumetric Microhemodynamics of Loco-Motor System Tissues with Laser Doppler Flowmetry

2004 ◽  
Vol 11 (1) ◽  
pp. 47-52
Author(s):  
A I Krupatkin ◽  
V G Golubev ◽  
D E Panov ◽  
M V Merkulov ◽  
V V Yulov ◽  
...  
Keyword(s):  
Blood Flow ◽  
Laser Doppler Flowmetry ◽  
Dynamic Control ◽  
Vertical Plane ◽  
Laser Doppler ◽  
Microvascular Blood Flow ◽  
Nerve Lesion ◽  
Cutaneous Blood Flow ◽  
Doppler Flowmetry ◽  
Cutaneous Blood

Twenty eight volunteers and 46patients (18 with old complete anatomic rupture of n. medianus (CARN), 14 with intratrancal neuroma after failed priamary suture, 14 with partial anatomic nerve lesion (PANL)) were examined using laser doppler flowmetry (LDF) of fingers skin in red (R) and infrared (IR) diaposons and wavelet-analysis of oscillations of microvascular blood flow. Formulae for calculation of indicis of local volumetric total (VTBF), nutritious (NVBF), shunting (VSBF) microvascular cutaneous blood flow, resistence to blood inflow anf outflow, microvascular pressure were suggested. Reliable positive correlation of temperature with NVBF and VTBF in red diapason was shown. The advantages of volumetric LDF parameters in old CARN were demonstrated. In old CARH and In intratrancal neuroma the decrease of VTBF with deficit of NVBF was noted. Correlation between VTBF in red and infrared diaposons enabled to assess the distribution of cutaneous blood flow in vertical plane. This methods allows to detect the causes of nutritious blood flow disturbance and to choose the correction tecnique. The advantages of LDF-indicis are its uninvasiveness, innocuity, possibilities to perform dynamic control and obtain information.

Peculiarities of microcirculation in periodont tissues in children of key age groups sufficient type 1 diabetes. Part II

2019 ◽  
Vol 24 (2) ◽  
pp. 108-119 ◽  
Author(s):  
B. N. Davydov ◽  
D. A. Domenyuk ◽  
S. V. Dmitrienko
Keyword(s):  
Diabetes Mellitus ◽  
Blood Flow ◽  
Type 1 Diabetes ◽  
Type 1 Diabetes Mellitus ◽  
Laser Doppler Flowmetry ◽  
Laser Doppler ◽  
Diabetic Microangiopathy ◽  
Healthy Children ◽  
Doppler Flowmetry

Relevance. Morpho-functional changes in peripheral circulation established in type 1 diabetes mellitus correlate with changes in central hemodynamics, allowing the use of microcirculation indicators as diagnostic and prognostic criteria for assessing the degree of functional vascular disorders. Identifcation of microcirculation features of the blood by the method of laser Doppler flowmetry in children with different experience of type 1 diabetes in key age categories.Materials and methods. The study included 67 children with type 1 diabetes mellitus aged 12-15 years with an experience of the disease from six months to ten years. The comparison group consisted of 38 healthy children. The state of the microvasculature was assessed by laser Doppler flowmetry using a laser analyzer for capillary blood flow LAKK-OP.Results. In children with an experience of type 1 diabetes of less than two years, microcirculation disorders in periodontal tissues correspond to the hyperemic form, accompanied by increased perfusion, a decrease in the amplitude of low-frequency oscillations, increased heart rate, high blood flling, and blood flow bypass. For children with an endocrinopathy experience of more than three years, microcirculation disorders correspond to a stagnant form, combined with a decrease in perfusion due to stagnation of blood in the venular link, endothelial domination with suppression of neurogenic and cardiac fluctuations, low efciency and redistribution of blood flow in favor of the nutritive link.Conclusions. With the increase in experience, the degree of compensation of type 1 diabetes, the progression of diabetic microangiopathy, it is advisable to designate two stages of development of microcirculatory disorders. Early – compensatory with active adaptation, including neurogenic and endothelial regulation mechanisms. Late – decompensation with passive adaptation, supporting the effectiveness of microcirculation due to myogenic control of regulation, shunting and increasing the rate of blood outflow.

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