Assessment of changes in intrarenal blood flow in conscious rats using laser-Doppler flowmetry

1993 ◽  
Vol 264 (6) ◽  
pp. F956-F962 ◽  
Author(s):  
S. Lu ◽  
D. L. Mattson ◽  
R. J. Roman ◽  
C. G. Becker ◽  
A. W. Cowley
Keyword(s):  
Blood Flow ◽  
Fiber Optic ◽  
Recovery Period ◽  
Laser Doppler ◽  
Intravenous Bolus ◽  
Ang Ii ◽  
Doppler Flowmetry ◽  
Conscious Rats ◽  
Fiber Optic Probes

The present study was designed to develop, for the first time, a method that allows long-term repeated measurements of renal cortical blood flow (CBF) and medullary blood flow (MBF) in conscious unanesthetized rats. The use of fiber-optic probes (0.5 mm diam) for the chronic measurement of renal CBF and MBF was evaluated. Basal renal cortical and medullary laser-Doppler flow (LDF) signals and the responses to intravenous bolus injections of angiotensin II (ANG II, 12.5 ng) were determined every other day for 11 days in conscious Sprague-Dawley rats (n = 9). A recovery period of 5-7 days after surgery was required before stable signals were obtained from the implanted probes. Thereafter, the fiber-optic probes gave reproducible laser-Doppler measurements of CBF and MBF for 11 days. The CBF and MBF responses to intravenous bolus injections of ANG II (12.5 ng) were also constant during this period. Chronic implantation of the fiber-optic probes caused minimal tissue damage and did not significantly alter urine concentrating ability or renal function. These findings suggest that LDF technique with chronically implanted optical fibers provides a new tool for the continuous long-term monitoring of regional blood flow in the kidney of conscious rats.

Effects of angiotensin on renal cortical and papillary blood flows measured by laser-Doppler flowmetry

1991 ◽  
Vol 261 (6) ◽  
pp. F998-F1006 ◽  
Author(s):  
M. S. Nobes ◽  
P. J. Harris ◽  
H. Yamada ◽  
F. A. Mendelsohn
Keyword(s):  
Blood Flow ◽  
Laser Doppler Flowmetry ◽  
Renal Perfusion ◽  
Laser Doppler ◽  
Ang Ii ◽  
Doppler Flowmetry ◽  
Blood Flows ◽  
Prostaglandin Synthase ◽  
Renal Cortical Blood Flow ◽  
Synthase Inhibitor

The effects of angiotensin II (ANG II) or angiotensin III (ANG III) on renal cortical blood flow (CBF) or papillary blood flow (PBF) were investigated in Inactin-anesthetized young rats with the use of laser-Doppler flowmetry. Infusion of equimolar pressor doses of ANG II (300 ng.kg-1.min-1 iv) or ANG III (267 ng.kg-1.min-1) decreased CBF by 31 +/- 2.6% (P less than 0.001) and 20.3 +/- 3.2% (P less than 0.01), respectively but increased PBF by 19 +/- 6.1% (P less than 0.05) and 14.6 +/- 4.4% (P less than 0.05). The ANG II-induced increase in PBF was not prevented by aortic clamping to maintain constant renal perfusion pressure or pretreatment with the prostaglandin synthase inhibitor, indomethacin. The nonpeptide ANG II receptor antagonist, DuP 753 completely abolished the systemic and intrarenal effects of ANG II. After pretreatment with a kallikrein inhibitor, aprotinin, ANG II infusion increased mean arterial pressure but did not affect PBF, suggesting that kinins, but not prostaglandins, modulate the action of systemic ANG II on PBF. We conclude that circulating ANG II induces vasoconstriction in the cortex and also promotes the intrarenal production of kinins, which act to enhance papillary blood flow.

Changes in cytochrome oxidation in outer and inner stripes of outer medulla

1991 ◽  
Vol 261 (5) ◽  
pp. F849-F857
Author(s):  
J. L. Atkins ◽  
S. P. Lankford
Keyword(s):  
Blood Flow ◽  
Fiber Optic ◽  
Outer Medulla ◽  
Doppler Flowmetry ◽  
Medullary Blood Flow ◽  
Fiber Optic Probes ◽  
Rate Of Oxygen Consumption ◽  
Outer Stripe ◽  
Cytochrome Oxidation ◽  
Reflectance Measurements

To examine regional cytochrome oxidation in the outer medulla, we developed fiber optic probes that allowed us to obtain localized reflectance measurements from the outer and inner stripes of the outer medulla. We measured directional changes in cytochrome oxidation in these two regions. In the outer stripe furosemide surprisingly caused a significant decrease in cytochrome oxidation. The decrease occurred concomitantly with a fall in outer medullary blood flow as measured by laser-Doppler flowmetry. Saralasin, an antagonist of angiotensin II caused a significant increase in cytochrome oxidation in the outer stripe. In the inner stripe furosemide tended to increase cytochrome oxidation, and saralasin had no effect. These results indicate that the two regions of the outer medulla may be affected differently by the same agent. They suggest that cytochrome oxidation in the outer stripe is predominantly influenced by outer medullary blood flow, whereas the inner stripe is predominantly influenced by the rate of oxygen consumption. The advantages and limitations of this methodology are discussed.

The response of skin perfusion and of rheological and immunological variables to intravenous prostanoid administration in Raynaud’s phenomenon secondary to collagenosis

VASA ◽  
2005 ◽  
Vol 34 (4) ◽  
pp. 243-249 ◽  
Author(s):  
Drinda ◽  
Neumann ◽  
Pöhlmann ◽  
Vogelsang ◽  
Stein ◽  
...  
Keyword(s):  
Laser Doppler Flowmetry ◽  
Raynaud’S Phenomenon ◽  
Raynaud's Phenomenon ◽  
Plasma Viscosity ◽  
Laser Doppler ◽  
Erythrocyte Aggregation ◽  
Control Group ◽  
Long Term Effects ◽  
Doppler Flowmetry

Background: Prostanoids are used in the treatment of Raynaud’s phenomenon and acral perfusion disorders secondary to collagenosis. In subjective terms, intravenous administration of these agents produces success in more than 50% of patients. The therapeutic outcome of clinical administration of alprostadil or iloprost may vary from individual to individual. Patients and methods: The following variables were analysed in a cross-over study in 27 patients with collagenosis and Raynaud’s phenomenon: plasma viscosity and erythrocyte aggregation (rheological variables), partial pressure of oxygen and laser Doppler flowmetry in the finger region, and lymphocyte phenotyping and interleukin (IL) determinations (immunological variables). Results: Laser Doppler flowmetry revealed significant differences between patients with secondary Raynaud’s phenomenon and a control group of 25 healthy subjects. Laser Doppler readings did not change significantly as a result of the treatments. Therapy with iloprost produced a reduction in IL-1beta, L-selectin (CD 62 L) and IL-6. Conclusion: The change in immunological variables due to iloprost may explain the long-term effects of prostaglandins in the treatment of Raynaud’s phenomenon. From our results it is not possible to infer any preference for iloprost or alprostadil.

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.

scholarly journals WALANT–Epinephrine injection may lead to short term, reversible episodes of critical oxygen saturation in the fingertips

2021 ◽  
Vol 141 (3) ◽  
pp. 527-533
Author(s):  
P. Moog ◽  
M. Dozan ◽  
J. Betzl ◽  
I. Sukhova ◽  
H. Kükrek ◽  
...  
Keyword(s):  
Blood Flow ◽  
Oxygen Saturation ◽  
Substantial Reduction ◽  
Tissue Perfusion ◽  
Critical Levels ◽  
Short Term ◽  
Doppler Flowmetry ◽  
Epinephrine Injection ◽  
Venous Oxygen Saturation

Abstract Introduction Although the WALANT technique’s long-term safeness has been demonstrated in many studies, there are only few data investigating its short-term effects on tissue perfusion and oxygen levels. It was hypothesized that, temporarily, critical levels of tissue perfusion may occur. Methods Seventeen patients, who were scheduled for different procedures in WALANT technique, were injected with 5–7 ml of 1% Articain containing 1:200,000 epinephrine at the finger base. Capillary-venous oxygen saturation, hemoglobin volume in the capillaries, and relative blood flow in the fingertips were recorded once per second by white light spectrometry and laser Doppler flowmetry before, during and after injection for an average of 32 min. Results Clinically, no persistent tissue malperfusion was observed, and there were no postoperative complications. Capillary-venous oxygen saturation was reduced by ≥ 30% in seven patients. Critical levels of oxygen saturation were detected in four patients during 13 intervals, each lasting for 132.5 s on average. Oxygen saturation returned to noncritical values in all patients by the end of the observation period. Blood flow in the fingertips was reduced by more than 30% in nine patients, but no critical levels were observed, as with the hemoglobin. Three patients demonstrated a reactive increase in blood flow of more than 30% after injection. Conclusions Injection of tumescent local anesthesia containing epinephrine into finger base may temporarily cause a substantial reduction in blood flow and lead to critical levels of oxygen saturation in the fingertips. However, this was fully reversible within minutes and does not cause long-term complications.

scholarly journals Laser Doppler blood flowmeter as a useful instrument for the early detection of lower extremity peripheral arterial disease in hemodialysis patients: an observational study

2019 ◽  
Vol 20 (1) ◽  
Author(s):  
Takeo Ishii ◽  
Shizuka Takabe ◽  
Yuki Yanagawa ◽  
Yuko Ohshima ◽  
Yasuhiro Kagawa ◽  
...  
Keyword(s):  
Blood Flow ◽  
Peripheral Arterial Disease ◽  
Early Stage ◽  
Arterial Disease ◽  
Hemodialysis Patients ◽  
Laser Doppler ◽  
Doppler Flowmetry ◽  
Skin Perfusion ◽  
Dorsal Area ◽  
Peripheral Arterial

Abstract Background A simpler method for detecting atherosclerosis obliterans is required in the clinical setting. Laser Doppler flowmetry (LDF) is easy to perform and can accurately detect deterioration in skin perfusion. We performed LDF for hemodialysis patients to determine the correlations between blood flow in the lower limbs and peripheral arterial disease (PAD). Methods This retrospective study included 128 hemodialysis patients. Patients were categorized into the non-PAD group (n = 106) and PAD group (n = 22), 14 early stage PAD patients were included in the PAD group. We conducted LDF for the plantar area and dorsal area of the foot and examined skin perfusion pressure (SPP) during dialysis. Results SPP-Dorsal Area values were 82.1 ± 22.0 mmHg in the non-PAD, and 59.1 ± 20.3 mmHg in PAD group, respectively (p < 0.05). The LDF-Plantar blood flow (Qb) values were 32.7 ± 15.5 mL/min in non-PAD group and 21.5 ± 11.3 mL/min in PAD group (p < 0.001). A total of 21 non-PAD patients underwent LDF before and during dialysis. The LDF-Plantar-Qb values were 36.5 ± 17.6 mL/min before dialysis and 29.6 ± 17.7 mL/min after dialysis (p < 0.05). We adjusted SPP and LDF for PAD using logistic regression, SPP-Dorsal-Area and LDF-P were significantly correlated with PAD (p < 0.05). The receiver-operating characteristic curve analysis indicated cut-off values of 20.0 mL/min for LDF-Plantar-Qb during dialysis. Conclusion LDF is a simple technique for sensitive detection of early-stage PAD. This assessment will help physicians identify early-stage PAD, including Fontaine stage II in clinical practice, thereby allowing prompt treatment.

Sign in / Sign up

Export Citation Format

Share Document