To investigate the effects of the free radical, 1,1-Diphenyl-2-picylhydrazyl, on cochlear blood flow, 20 guinea pigs were divided into 3 groups at random, 6 for control group, 6 for 1 mmol/L group and 8 for 0.1 mmol/L group. 2 microliters vehicle or drugs were dropped into round window membrane (RWM). Cochlear microcirculation was monitored by laser Doppler flowmeter (LDF), and mean arterial blood flow (MABP), which was transferred by pressure conductor sensor and preamplifier, was simultaneously recorded on the computer. Our results showed that MABP was stable throughout the experiment. Cochlear blood flow (CBF) increased by 10.32% (P < 0.05) in 1 mmol/L group, and decreased by 4.89% in 0.1 mmol/L group (P < 0.05). In control group cochlear microcirculation showed no significant changes. It is concluded that DPPH exerted effects on cochlear microcirculation.
Blood Flow Velocity ; Cochlea/*blood supply ; Free Radicals/pharmacology ; Laser-Doppler Flowmetry ; Microcirculation/drug effects ; Picrates/*pharmacology ; Random Allocation

BACKGROUNDResearches in arterial elasticity have increased over the past few years. We investigated the effects of simvastatin on vascular stiffness in fat fed rabbits by ultrasonography.

METHODSThirty rabbits were assigned randomly to 3 groups: normal control group (A), the cholesterol group (B), simvastatin group (C: high fat diet for 4 weeks and high fat diet + simvastatin for further 4 weeks). Stiffness coefficient, pressure strain elastic modulus and velocity of pulse waves in abdominal aorta and femoral artery were measured by ultrasonographic echo tracking at the end of the 4th and the 8th weeks.

RESULTSAt the end of the 4th week, stiffness coefficient, pressure strain elastic modulus and pulse wave velocity of femoral artery were significantly increased in group B compared with those in group A. Similarly, at the end of the 8th week, the same parameters of abdominal aorta were significantly increased in group B compared with those in group A. In contrast, stiffness coefficient, pressure strain elastic modulus and pulse wave velocity of femoral artery were significantly decreased in group C compared with those in group B, however, there was no significant difference in parameters of abdominal aorta between groups B and C.

CONCLUSIONShort term administration of simvastatin can improve the elasticity of femoral artery but not abdominal aorta.

Animals ; Anticholesteremic Agents ; therapeutic use ; Aorta, Abdominal ; drug effects ; Blood Flow Velocity ; drug effects ; Dietary Fats ; adverse effects ; Femoral Artery ; drug effects ; Rabbits ; Random Allocation ; Simvastatin ; therapeutic use

This study was performed to examine the influence of isoflurane anesthesia on the pulsatility index (PI) and the peak systolic velocity (PSV) of the blood flow in the basilar artery of dogs by duplex Doppler ultrasonography. Twelve healthy dogs were used to measure the PI and the PSV under the conscious state and isoflurane anesthesia. The pulsatility index (PI) and the peak systolic velocity (PSV) in the basilar artery were measured five times with random intervals. The blood pressure was measured. The PI and PSV values in dogs under isoflurane anesthesia were 1.37 +/- 0.32 and 72 +/- 19 cm/sec, whereas those in the conscious dogs were 1.37 +/- 0.13 and 81 +/- 16 cm/sec, respectively. The indirect mean arterial systolic and diastolic pressures under isoflurane anesthesia were 107 and 51 mmHg, whereas those in the conscious dogs were 133 and 74 mmHg. Though the isoflurane is generally known to induce hypotension, there were no significant differences in the PI and PSV between the isoflurane-anesthetized and the conscious dogs. In conclusion, the isoflurane anesthesia did not influence the PI and PSV in the basilar artery of dogs.
Anesthetics, Inhalation/*pharmacology ; Animals ; Basilar Artery/drug effects/*ultrasonography ; Blood Flow Velocity/drug effects/veterinary ; Blood Pressure/drug effects ; Cerebrovascular Circulation/drug effects ; Dogs/*physiology ; Female ; Isoflurane/*pharmacology ; Male ; Pulsatile Flow/drug effects ; Ultrasonography, Doppler, Duplex/veterinary

OBJECTIVETo investigate the drag-reducing effect of polyethylene oxide (PEO) on the velocity of red blood cells in rat cremaster microcirculation.

METHODSBlood samples were collected from 6 Wistar male rats (100-110 g) via the post-orbital venous plexus. The red blood cells were separated by centrifugation and labeled by fluorescinisothiocyate (FITC). After successful establishment of cremaster model, the labeled red blood cells were injected into the jugular vein, and the microcirculation was observed and recorded under fluorescence microscope. The hemodynamic parameters and microcirculation video was recorded every 4 min since 4 min before PEO or normal saline injection. Both PEO (10 ppm) and normal saline was injected into the same rat in random sequence at a constant rate of 3.5 ml/h for 20 min followed by observation for another 20 min. The velocity of the labeled-red blood cells was determined by IPP 6.0 software.

RESULTSCompared with normal saline, PEO significantly increased the velocity of the red blood cells in the rat cremaster microcirculation (498.7-/+182.89 microm/s vs 773.54-/+308.27 microm/s, P=0.012). No significant changes in the heart rate and arterial blood pressure were observed during the experiment (P=0.836, P=0.420).

CONCLUSIONPEO at an extremely low concentration can significantly increase the velocity of the red blood cells in rat cremaster microcirculation and produces no significant impact on heart rate and arterial blood pressure.

Animals ; Blood Flow Velocity ; drug effects ; Male ; Microcirculation ; drug effects ; physiology ; Muscle, Smooth ; blood supply ; Polyethylene Glycols ; pharmacology ; Rats ; Rats, Wistar ; Testis

This study was aimed to assess the effect of Shenfu injection on different circulation state. Using a microcirculation microscope system, we observed mice's auricle micro-artery diameter, density of capillary, blood velocity in different circulation state (i.e. normal state, epinephrine or endotoxin induced microcirculation disturbance state) after administering Shenfu injection into their caudal vein, and we compared the Shenfu group with Shenmai group and Dexamethasone group. The results showed that Shenfu injection causes the auricle microartery diameter to enlarge and the density of capillary and blood velocity to increase in different microcirculation state, and such effect is especially notable on the epinephrine induced microcirculation disturbance group and endotoxin induced microcirculation disturbance group; the effect of Shenfu injection is stronger than that of Shenmai injection and similar to Dexamethasone injection. In addition, Shenfu injection was shown to have remarkable effect on resisting the lowering of limb temperature when the mice are attacked by endotoxin.
Animals ; Blood Flow Velocity ; drug effects ; Drugs, Chinese Herbal ; administration & dosage ; pharmacology ; Ear ; blood supply ; Endotoxins ; toxicity ; Epinephrine ; toxicity ; Female ; Injections ; Male ; Mice ; Microcirculation ; drug effects ; physiology

OBJECTIVETo detect the velocity and viscosity of blood flow of the vertebral arteries, the apoptotic cell and apoptotic related protein in the brain in order to offer theoretical foundation for the treatment of cervical spondylopathy of the vertebral artery type with the eliminat dampness resolv phlegm method.

METHODSSixty male Japanese big ear rabbits were divided randomly into normal sodium group (A), Flunarizine group (B), low dosage Wendantang group (C), large dosage Wendantang group (D), Flunarizine group combined with large dosage Wendantang group (E), normal group (F). Each group had 10 rabbits. Xiaozhiling injection was injected around the vertebral arteries of rabbits in group A, B C, D, E to make the model of the cervical spondylopathy of the vertebral artery type. Normal sodium (20 ml x kg(-1)d(-1)) was apply through intragastric administration in group A, F; Flunarizine (0.8 mg x kg(-1)d(-1)), low dosage Wendantang (1 g x ml(-1)d(-1)), large dosage Wendantang (2 g x ml(-1)d(-1)), Flunarizine combined with large dosage Wendantang were respectively apply through intragastric administration in group B, C, D, E. The velocity and viscosity of blood flow of the vertebral arteries, the apoptotic cell and apoptotic protein in the brain were detected before and after the treatment.

RESULTSSatisfactory animal model were obtained in group A, B, C, D, E. The rabbits of group E had the most improvement of the velocity and viscosity of blood flow of the vertebral arteries while at meantime, which had the lowest apoptotic index and apoptotic related protein expression in the brain.

CONCLUSIONThe routine treatment for the cervical spondylopathy of the vertebral artery combined with eliminat dampness resolv phlegm method could improve velocity and viscosity of blood flow of the vertebral arteries, which maybe relate with reduction of apoptosis in the brain.

Animals ; Blood Flow Velocity ; drug effects ; Disease Models, Animal ; Drugs, Chinese Herbal ; administration & dosage ; Humans ; Male ; Rabbits ; Random Allocation ; Spondylosis ; drug therapy ; physiopathology ; Vertebral Artery ; drug effects ; physiopathology

OBJECTIVETo observe the effect of polyethylene oxide (PEO) solution at different concentrations on abdominal aortic blood flow and vascular resistance in rats and evaluate the safety and drag-reducing effect of PEO solution.

METHODSThirty-two rats were anesthetized and randomly divided into 4 groups. An ultrasonic flow probe was deployed on the abdominal aorta (5 mm above the common iliac artery) to measure the blood flow. The carotid artery pressure, iliac artery pressure, iliac vein pressure, central venous pressure (CVP) and ECG were also monitored. Saline or different concentrations of PEO [(1x10(-6)(low), 1x10(-5)(middle) and 5x10(-5)(high) g/ml)] were injected in the 4 groups of rats through the caudal vein at a constant rate of 5 ml/h for 20 min, and the changes of the vascular resistance was observed. RESULTS After injections of 1x10(-6) and 1x10(-5) g/ml PEO, the abdominal aortic flow increased significantly (P<0.05) while the vascular resistance was reduced (P(low)=0.052, P(middle)<0.001) as compared to those in the saline control group. Following the injection with 5x10(-5) g/ml PEO, the abdominal aortic flow increased to a threshold in the initial 4 min, after which it rapidly decreased to approach the baseline levels despite continuous infusion. Blood pressure remained stable after the injections except for 5x10(-5) g/mlPEO injection, which resulted in a reduction of the blood pressure by about 10 mmHg (P=0.014). The heart rate and CVP both underwent no significant changes following the injections.

CONCLUSIONThe drag-reducing effect of PEO is closely related to its concentration, and compared with 1x10(-6) g/ml, 1x10(-5) g/ml PEO more effectively increases the blood flow and decreases the resistance. The effectiveness and safety of EPO are attenuated at a concentration higher than 5x10(-5) g/ml.

Animals ; Aorta, Abdominal ; physiology ; Blood Flow Velocity ; drug effects ; Dose-Response Relationship, Drug ; Male ; Polyethylene Glycols ; pharmacology ; Random Allocation ; Rats ; Rats, Wistar ; Vascular Resistance ; drug effects

AIMTo investigate the effect of nimodipine (NM) on cerebral blood flow (CBF) in dogs following intranasal administration.

METHODSNM solution was administered intranasally, intravenously (i.v.), and orally to dogs and the change of CBF was determined by using electromagnetic blood flowmeter. MFLab experimental program was applied to monitor the experimental process and analyze data.

RESULTSCBF markedly increased after iv and intranasal application, while large variance was observed after oral dosing. CBF in dogs after three administrations increased by 26.4%, 28.0% and 8.5%, respectively, compared with that of baseline. Following intranasal administration, the onset of action was slightly slower than that after iv injection [(5 +/- 4) min vs (2.2 +/- 1.2) min], however the duration of improvement was the longest [ (25 +/- 17) min].

CONCLUSIONIntranasal delivery for NM can be a promising alternative to parenteral or oral administration.

Administration, Intranasal ; Administration, Oral ; Animals ; Blood Flow Velocity ; drug effects ; Cerebrovascular Circulation ; drug effects ; Dogs ; Female ; Injections, Intravenous ; Male ; Nimodipine ; administration & dosage ; pharmacology ; Vasodilator Agents ; administration & dosage ; pharmacology

OBJECTIVEPatient with myocardial bridging (MB) usually has a benign prognosis, but some MB patients might experience myocardial ischemia, infarction and sudden cardiac death, especially during active physical activities. The purpose of the study was to study the stress-induced blood flow changes of the mural coronary artery in MB patients determined by intracoronary Doppler.

METHODSIn 8 patients with MB, the basic average peak velocity (bAPV), hyperemic average peak velocity (hAPV) of blood flow, coronary flow reverse (CFR) proximal and distal to the mural coronary artery were measured before and during intravenously dobutamine (10 microg kg-1 min-1, then add 10 microg kg-1 min-1 at 3 min interval till 40 microg kg-1 min-1) by intracoronary Doppler.

RESULTSThe baseline mural coronary diameter reduction was (51.7+/-21.4)% and significantly increased to (90.0+/-12.7)% (P<0.01) during dobutamine infusion. bAPV on the segments proximal and distal to the mural coronary artery significantly increased from (19.83+/-5.84) cm/s and (20.75+/-4.91) cm/s to (31.52+/-10.93) cm/s and (30.46+/-9.01) cm/s (all P<0.05 vs. baseline) respectively post dobutamine infusion. CFR measured at proximal and distal to myocardial bridging also significantly decreased from (2.91+/-0.62) and (2.46+/-0.82) to (2.17+/-0.66) and (1.83+/-0.51) (all P<0.01).

CONCLUSIONStress can significantly increase the compression of intramural coronary artery and reduce CFR on coronary segments both proximal and distal to the MB. Thus, active exercise might induce myocardial ischemia in patients with myocardial bridging.

Blood Flow Velocity ; Cardiotonic Agents ; pharmacology ; Coronary Circulation ; drug effects ; Coronary Vessel Anomalies ; physiopathology ; Coronary Vessels ; drug effects ; Dobutamine ; pharmacology ; Female ; Humans ; Male ; Middle Aged

The reliability and reliable indexes of quantitative assessment of coronary flow reserve (CFR) by using time-intensity curve (TIC) via myocardial contrast echocardiography were investigated. The TIC variables were obtained by employing acoustic densitometry (AD) technique before and after acetylcholine (Ach) injection in 12 dogs. Meanwhile, the correlation between these variables and CFR was analyzed. Among the variables derived from TIC, peak intensity (PI), area under the curve (AUC) and descending slope (DS) were increased significantly (P < 0.05) with the increase of coronary blood flow after Ach injection. Conversely, time-to-peak (TP), half-time of descent (HT), and mean-transit-time (MTT) were decreased remarkably (P < 0.0001). The PI and AUC ratios from post- to pre-Ach injection were strongly associated with CFR with the correlation coefficient (r) being 0.8366 and 0.8824, respectively. It is reliable by using the variables derived from TIC with myocardial contrast echocardiography to quantitatively evaluate regional myocardial CFR. The PI and AUC ratios from post- to pre-Ach injection are the reliable indexes for quantitative assessment of CFR.
Blood Flow Velocity/physiology ; Contrast Media ; Coronary Circulation/*physiology ; Coronary Vessels/physiology ; Coronary Vessels/ultrasonography ; *Echocardiography/methods ; *Image Processing, Computer-Assisted ; Observer Variation ; Regional Blood Flow/drug effects ; Regional Blood Flow/physiology ; Reproducibility of Results ; Ultrasonography, Interventional