Concentration Of Moving Blood Cells Research Articles

The effects of lower limb intermittent negative pressure therapy on the skin microcirculation perfusion of quadriceps in male rowers

To investigate the effects of intermittent negative pressure therapy on the skin microcirculation perfusion of quadriceps in male rowers, and to provide basis for the practical application of this method. Fourteen male rowers were selected from the national rowing team and randomly divided into experimental and control groups. The daily training plans of two groups were the same. The recovery intervention for experimental group was implemented by 20 minutes in the cube of Vacusport Regeneration System (German), 5 times per week for 4 weeks, no recovery intervention for control group. Microcirculation markers were collected by PeriFlux5000 system before and after the 4-week intervention. The markers included microcirculatory blood perfusion(MBP), average velocity of blood cells(AVBC), concentration of moving blood cells (CMBC), and values of the markers included basic values and post-heating values (44℃), difference before and after heating of the values was considered as the reserve capacity of those markers. The test results before the 4 weeks intervention showed there was no statistical difference between the two groups(P＞0.05). After the 4 weeks intervention: ①MBP: The post-heating value and the difference of the experimental group were significantly higher than those of the control group (P＜0.05). But there was no statistical inner-group difference. ②AVBC: The post-heating values and the difference in the experimental group were significantly lower than those in the control group (P＜0.05). Intra-group comparison found that the post-heating values after post-intervention were significantly reduced, compared with those of pre-intervention (P＜ 0.01); the difference after post-intervention was reduced significantly, compared with those in the pre-intervention (P＜0.05). ③CMBC: The post-heating values and the difference in the experimental group were significantly higher than those in the control group (P＜0.01). There were no statistical significant inner-group difference. Lower limb intermittent negative pressure therapy can improve the skin microcirculation of the quadriceps of the male rowers, which has a positive effect on the rapid recovery of physical fitness.

Dynamics of cutaneous laser Doppler flux with concentration of moving blood cells and blood cell velocity in legs with venous ulcers and in healthy legs.

Laser Doppler flux (LDF) is a product of the concentration of moving blood cells (CMBC) and the blood cell velocity (BCV). In an attempt to obtain more information about the cutaneous microcirculation in legs with venous ulcers and in healthy legs, the dynamics of the curves of the LDF, the CMBC, and the BCV were analyzed in 8 patients with venous leg ulcers and in 10 subjects with healthy legs. The curves of the CMBC and of the BCV were found to be in opposite phases both in the ulcerous legs and in the healthy legs. The maximal amplitude of the curves of the LDF and of the CMBC was greater in the legs with ulcers than in the healthy legs (p = 0.021 and p = 0.0085, respectively). The finding that the curves of the CMBC and the BCV were in opposite phase can be interpreted to reflect the capillary blood flow by fits and starts both in legs with venous ulcers and in healthy legs. The greater amplitude of the LDF and the CMBC in legs with venous ulcers reflects the blood flow in anatomically altered capillaries in those legs. It is useful to record the curves of the CMBC and the BCV together with the LDF because this gives additional information about the microcirculation of the skin.

Effect of Sympathetic Denervation on Rabbit Choroidal Blood Flow

In this study we demonstrate the existence of sympathetic innervation and compare the effect of unilateral or bilateral superior cervical sympathectomy on albino rabbit choroidal blood flow (CBF) during changes in perfusion pressure (PP). Forty albino rabbits weighing between 2.0 and 3.0 kg were randomly divided into three groups. The bilateral sympathectomy group (group S) included 10 rabbits (20 eyes) that received bilateral sympathectomy 1 week prior to the study. The unilateral sympathectomy group (group U) included 20 rabbits (20 eyes) that received unilateral sympathectomy 1 week prior to the study. Only the eyes ipsilateral to sympathectomy were utilized. The other 10 rabbits (20 eyes) served as controls (group N), each received the same procedure as the experimental groups except that the superior cervical ganglion (SCG) was preserved. The blood cell flux (PF), velocity (V), and concentration of moving blood cells (CMBC) were recorded simultaneously by means of a laser Doppler flowmeter (Perimed PF4001), while the intraocular pressure was increased linearly with a syringe pump. When the PP decreased steadily, the PF, V, and CMBC remained constant until PP <55 mm Hg, then decreased proportionally to the PP. When the PP decreased from 75 to 0 mm Hg, the PF, V and CMBC decreased from 100 to 6.87 ± 0.97%, 8.44 ± 0.92%, and 18.67 ± 0.91% in group N, to 18.56 ± 1.62%, 19.30 ± 1.84%, and 38.02 ± 9.10% in group U, and to 18.38 ± 2.89%, 16.78 ± 1.48%, and 34.58 ± 4.42% in group S. The changes in PF, V, and CMBC were similar in groups S and U. Both group S and U had higher PF, V, and CMBC values than group N at comparable PPs below 55 mm Hg. These results indicate that the SCG plays a role in CBF regulation. Both unilateral and bilateral sympathectomy led to a higher PF in both groups S and U rabbits, indicating increased CBF while PP decreased gradually. This suggests that the rabbit choroid does not receive crossed innervation. The plateau response in each curve demonstrates the presence of autoregulation. This autoregulation was unchanged by either unilateral or bilateral sympathetic denervation.

Bilateral Superior Cervical Ganglionectomy Increases Choroidal Blood Flow in the Rabbit

In this study, we evaluate the effect of bilateral superior cervical ganglionectomy on albino rabbit choroidal blood flow (CBF) in changes of perfusion pressure (PP). Twenty albino rabbits of either sex weighing between 2.0 and 3.0 kg were randomly divided into two groups. The experimental group (group S) included 10 rabbits (20 eyes) that received bilateral superior cervical ganglionectomy one week prior to the study. The other 10 rabbits (20 eyes) served as a control (group N): each received the same procedure as group S except that the superior cervical ganglion was preserved. By means of a laser Doppler flowmeter (Perimed PF4001), blood cell flux (PF), velocity (V), and concentration of moving blood cells (CMBC) were recorded simultaneously while intraocular pressure was increased linearly by a syringe pump. Blood pressure and intraocular pressure were continuously monitored. The laser beam focused on the posterior pole away from major retinal vessels. When PP decreased from 75 to 0 mm Hg, in group N, PF, V and CMBC decreased from 100% to 6.94 ± 0.91%, 8.41 ± 0.87%, and 19.38 ± 1.11%; in group S, it was 17.75 ± 2.58%, 16.78 ± 1.48%, and 34.58 ± 4.42%, respectively. Group S poses higher PF, V, and CMBC than group N while PP decreased gradually. These results indicate that the superior cervical ganglion plays a role in CBF regulation. Bilateral sympathectomy led to a higher PF in the group S rabbits, indicating increased CBF. PF, V, and CMBC remained constant until PP <55 mm Hg demonstrated the existence of CBF autoregulation within a limited perfusion range in both groups. This autoregulation did not change after sympathectomy.

The short-term effect of pentoxifylline on rabbit choroidal blood flow.

This study evaluates the effect of different doses ofpentoxifylline on rabbit choroidal blood flow (CBF). Sixteen albino rabbits of both sexes, weighing 2.0-3.0 kg, were randomly separated into four groups. The first group of rabbits received 2 ml normal saline injection through the ear vein. They served as the control group (group n). Three different doses of pentoxifylline, 1 mg/kg, 5 mg/kg, and 10 mg/kg, were injected intravenously to groups p1, p5 and p10, respectively. By means of a laser Doppler flowmeter, the blood cell flux (PF), velocity, and the concentration of moving blood cells (CMBC) were recorded simultaneously. The laser probe was advanced through the pars plana and positioned near the retinal surface. The mean arterial pressure was recorded at the same time. There was a significant increase in PF at 1, 5 and 10 min in group p10 rabbits compared with the control group (p=0.0005, 0.0416, and 0.0087, respectively). The velocity increased at 5 min in group p5 rabbits (p=0.0082) and at 1, 5 and 10 min in group p10 rabbits (p=0.0188, 0.0080, and 0.0207, respectively) as compared with the controls. The CMBC decreased after injection of pentoxifylline and reached statistical significance at 5 and 10 min in group p5 rabbits (p=0.0019 and 0.0046, respectively) and at 5 min in group p10 rabbits (p=0.0447). These results show that larger doses of pentoxifylline (10 mg/kg) increased the CBF of rabbits. This effect was achieved primarily by an increase in blood cell velocity.

Intranasal Histamine Challenge in Normal Subjects and Allergic Rhinitis before and after Intranasal Budesonide Studied with Rhinostereometry and Micromanipulator-Guided Laser D oppler Flowmetry

Ten healthy subjects and 10 patients suffering from allergic rhinitis to birch pollen were investigated with the combination of rhinostereometry and laser Doppler flowmetry, thus simultaneously measuring changes in mucosal swelling and microcirculation, following intranasal histamine challenge. Compared to normals, the allergics had a higher degree of congestion and a lower increase in perfusion and velocity of flow. In the allergics there was a decrease in CMBC (concentration of moving blood cells) that was not seen in normals. The decrease in CMBC seen in allergics could be attributed to an increase in vascular permeability producing an interstitial edema, a well-known effect of histamine. After treatment with 1 week of intranasal steroid, most of the differences in the reaction pattern between normals and allergics had disappeared.

Laser-Doppler measurements of concentration and velocity of moving blood cells in rat cerebral circulation.

In brain cortex all capillaries are perfused with plasma at anyone time while the flow of blood cells is heterogeneous. Increased blood flow is associated with increased number of moving erythrocytes in the microcirculation, while capillary recruitment in its classical anatomical sense appears not to exist in the brain. Modulation of the concentration of flowing erythrocytes may influence the oxygen supply to the tissue. Therefore, we examined the possibility that laser-Doppler flowmetry (LDF) could be used to quantify changes in the microvascular concentration of moving blood cells (CMBC) and blood cell velocity (< v >) by comparing LDF measurements with electromagnetic flow measurements in vitro, and confocal laser-scanning microscopy in vivo in the brain of anaesthetized male Wistar rats. In vitro measurements showed that CMBC was affected by changes in haematocrit, while < v > correlated almost linearly with blood cell velocity measured electromagnetically within a relevant physiological range. In vivo studies during hypercapnia (PaCO2 from 39 +/- 4 to 66 +/- 5 mmHg) with confocal laser scanning microscopy disclosed a 39 +/- 10% increase of cortical capillary erythrocytes, while CMBC measured with LDF increased by 37 +/- 5%. Erythrocyte flow velocity in brain cortex capillaries increased by 65 +/- 17% with confocal microscopy as compared to 72 +/- 8% with LDF. Local electrical stimulation of cerebellar cortex, and application of adenosine or sodium-nitroprusside, increased CMBC and < v > simultaneously, while during hypercapnia the < v > increase preceded the CMBC increase by 30 s. The CMBC rise rapidly reached a steady state in response to all types of stimulation, while < v > continued to increase during the major part, or the entire stimulation period. In conclusion, our data support the hypothesis that LDF may be useful for haemodynamic studies of brain microcirculation.

Effect of Compression Stockings on the Skin Microcirculation in Chronic Venous Insufficiency

Objective: To use a single fibre laser Doppler fluxmeter to assess the microcirculatory effects of compression stockings. Design: Controlled study comprising patient and control groups. Setting: Department of Surgery, University College London Medical School, London, UK. Patients and participants: Ten patients with lipodermatosclerosis caused by chronic venous insufficiency and 10 control subjects. Interventions: Measurements were made from the liposclerotic skin of patients and 8 cm above the medial malleolus in controls. Laser Doppler flux (LDF), blood ce velocity (BCV) and concentration of moving blood cells (CMBC) were recorded with the subject lying supine. A class II graduated compression stocking was applied to the leg and laser Doppler recordings were repeated. The protocol was repeated with the subject sitting. Main outcome measures: The effects of a compression stocking on LDF, BCV and CMBC in the horizontal and sitting positions were measured. Results: In patients in the supine position, the compression stocking resulted in a 28% median increase in LDF ( p = 0.03), with a corresponding 29% median increase in BCV. There was no significant change in CMBC. In the sitting position, the compression stocking caused a 105% median increase in LDF ( p &lt; 0.01) due to a corresponding 89% median increase in BCV ( p = 0.01); there was only 25% median increase in CMBC. The effects of compression in controls were similar to those in patients. Conclusion: Compression stockings may be effective in the treatment of chronic venous insufficiency by increasing the microcirculatory flow velocity.

The effect of arterial pressure on the ocular pressure-volume relationship in the rabbit

The purpose of this study was to quantify the effect of mean arterial pressure (MAP) on the ocular pressure-volume relationship. The experiments were performed in pentobarbital anesthetized rabbits instrumented with occluders on the thoracic aorta and inferior vena cava to control MAP which was measured via a cannula in the central ear artery. To vary the ocular volume and measure the intraocular pressure (IOP), two 23 gauge needles were inserted through the pars plana into the vitreous: one needle was connected to a saline-filled syringe and the other needle was connected to a pressure transducer. In one group of animals (n = 5), pressure-volume curves were determined at MAPs of 100, 80, 60, 40 and 20 mmHg and post mortem by cumulative saline injections (2 microliters) every 1-1.5 sec. In a second group (n = 7), pressure-volume curves were obtained at MAPs of 80, 60 and 40 mmHg and post mortem by saline infusion at 0.5 microliter sec-1 until the IOP reached 100 mmHg. The infusion protocol was repeated in a third group (n = 11) where the choroidal flux and the concentration of moving blood cells (CMBC) were measured by a laser Doppler flowmeter as indices of choroidal blood flow and the blood volume, respectively. MAP had three primary effects on the ocular pressure-volume relationship: (1) the baseline IOP varied exponentially with MAP, (2) the steepness of the initial portion of the pressure-volume curves was MAP-dependent and (3) the curves exhibited a 'plateau' as the IOP approached the prevailing MAP at MAPs > or = 40 mmHg. All of the curves in the living eye intersected and became indistinguishable from the post mortem curve when the IOP exceeded the prevailing MAP. The flux and CMBC measurements indicated that the MAP-dependence of the initial portion of the curves was due to failure of choroidal autoregulation and diminished increases in choroidal blood volume at the lower MAPs, and that the plateau portion of the curves was due to expulsion of blood from the eye. It is concluded that MAP has a significant effect on the ocular pressure-volume relationship.

Peripheral assessment of phenylephrine-induced vasoconstriction by laser Doppler flowmetry and its potential relevance to homeostatic mechanisms.

Cutaneous laser Doppler flowmetry enables monitoring of changes in skin perfusion by quantifying the phase shift of laser light induced by moving red blood cells under a fiberoptic probe. It thus can identify the presence of and response to a vasoconstrictive stimulus. However, aspects of the technique must be defined before it can be used with maximum effectiveness. We evaluated the responses of two different laser Doppler outputs, the concentration of moving blood cells (CMBC) and red cell flux (CMBC times cell velocity), and the responses at two sites of probe application, the finger and forearm, during systemic infusions of phenylephrine. Eight healthy volunteers were monitored with a brachial blood pressure cuff, ECG, and laser Doppler flowmeter probes applied to the palmar surface of the fourth finger and volar forearm of the arm opposite the pressure cuff. After baseline readings were obtained, the subjects received three 10-minute intravenous infusions of phenylephrine at rates of 0.4, 0.8, and 1.6 micrograms.kg-1.min-1. The two parameters, flux and CMBC, trended similarly. Flux and CMBC at the finger declined significantly in response to each infusion (P < .05 using repeated-measures ANOVA with Duncan's multiple range test). In contrast, flux and CMBC of the forearm had highly variable responses, with an overall increase during each infusion (P < .05 for % delta of forearm versus % delta of finger readings during the 0.4 microgram.kg-1.min-1 infusion). Heart rate declined significantly during each infusion, consistent with a baroreceptor-mediated response, even though systolic and diastolic blood pressures each increased by less than 2 mm Hg during the 0.4 microgram.kg-1.min-1 infusion. As expected, laser Doppler readings at the finger decreased during infusion of an alpha 1-agonist. Although, like the digital vessels, forearm vessels have the potential to constrict, the increases in forearm readings suggest that these vessels are highly susceptible to homeostatic responses. The increase in CMBC (a parameter that is sensitive primarily to local changes in vascular caliber) suggested vasodilation of the underlying vessels. The forearm vasodilation and the concomitant decline in heart rate most likely represented vagally mediated baroreceptor activity, which was altered even though blood pressure changed minimally during the 0.4 microgram.kg-1.min-1 infusion. Thus, integrated assessment of skin perfusion at the finger and forearm may provide valuable information about the direct and indirect effects of a vasoactive stimulus. The present application of laser Doppler flowmetry suggests activation of vasodilatory reflexes despite minimal changes in blood pressure.

Skin Blood Flow in Chronic Venous Insufficiency

Objective: To evaluate the skin temperature, laser Doppler flux (LDF), concentration of moving blood cells (CMBC) and speed of blood cells (SBC) in the liposclerotic and clinically normal skin of patients with chronic venous insufficiency. Design: Parallel groups study comparing patients with chronic venous insufficiency with control subjects. Setting: Vascular laboratory, Middlesex Hospital, University College and Middlesex School of Medicine, London, UK. Participants: Twenty patients with lipodermatosclerosis and chronic venous insufficiency comprised the disease group, and 15 subjects without venous disease comprised the control group. Main outcome measures: The skin temperature, LDF, CMBC and SBC were assessed in the gaiter area and on the dorsum of the foot. Results: A higher LDF (median LDF and interquartile range (IQR) = 132 (66–289), p = 0.001 (Mann-Whitney) and skin temperature (Median temperature and IQR = 31.1 (29.6–32.4), p = 0.001) was found in the liposclerotic skin of patients with chronic venous insufficiency compared with normal controls (median LDF and IQR = 49 (32–58); median temperature and IQR = 28 (27–30.3)). Similarly the LDF on the dorsum of the foot (median LDF and IQR = 73 (59–127), p = 0.03) and skin temperature on the dorsum of the foot (median temperature and IQR = 31.1 (30.4–32.1), p = 0.002) was significantly higher in the patients with chronic venous insufficiency compared with normal controls (median LDF and IQR = 55 (36–66), median temperature and IQR = 29.5 (26.7–30.7)). Conclusions: This study demonstrates that there is increased skin blood flow in both liposclerotic skin and clinically normal skin in patients with chronic venous insufficiency.