Changes In Tissue Blood Flow Research Articles

Spreading depolarization suppression from inter-astrocytic gap junction blockade assessed with multimodal imaging and a novel wavefront detection scheme

Spreading depolarizations (SDs) are an enigmatic and ubiquitous co-morbidity of neural dysfunction. SDs are propagating waves of local field depolarization and increased extracellular potassium. They increase the metabolic demand on brain tissue, resulting in changes in tissue blood flow, and are associated with adverse neurological consequences including stroke, epilepsy, neurotrauma, and migraine. Their occurrence is associated with poor patient prognosis through mechanisms which are only partially understood. Here we show in vivo that two (structurally dissimilar) drugs, which suppress astroglial gap junctional communication, can acutely suppress SDs. We found that mefloquine hydrochloride (MQH), administered IP, slowed the propagation of the SD potassium waveform and intermittently led to its suppression. The hemodynamic response was similarly delayed and intermittently suppressed. Furthermore, in instances where SD led to transient tissue swelling, MQH reduced observable tissue displacement. Administration of meclofenamic acid (MFA) IP was found to reduce blood flow, both proximal and distal, to the site of SD induction, preceding a large reduction in the amplitude of the SD-associated potassium wave. We introduce a novel image processing scheme for SD wavefront localization under low-contrast imaging conditions permitting full-field wavefront velocity mapping and wavefront parametrization. We found that MQH administration delayed SD wavefront's optical correlates. These two clinically used drugs, both gap junctional blockers found to distinctly suppress SDs, may be of therapeutic benefit in the various brain disorders associated with recurrent SDs.

Transmissive multifocal laser speckle contrast imaging through thick tissue

Laser speckle contrast imaging (LSCI) is a powerful tool for monitoring blood flow changes in tissue or vessels in vivo, but its applications are limited by shallow penetration depth under reflective imaging configuration. The traditional LSCI setup has been used in transmissive imaging for depth extension up to [Formula: see text]–[Formula: see text] ([Formula: see text] is the transport mean free path), but the blood flow estimation is biased due to the depth uncertainty in large depth of field (DOF) images. In this study, we propose a transmissive multifocal LSCI for depth-resolved blood flow in thick tissue, further extending the transmissive LSCI for tissue thickness up to [Formula: see text]. The limited-DOF imaging system is applied to the multifocal acquisition, and the depth of the vessel is estimated using a robust visibility parameter [Formula: see text] in the coherent domain. The accuracy and linearity of depth estimation are tested by Monte Carlo simulations. Based on the proposed method, the model of contrast analysis resolving the depth information is established and verified in a phantom experiment. We demonstrated its effectiveness in acquiring depth-resolved vessel structures and flow dynamics in in vivo imaging of chick embryos.

Improving accuracy of cerebral blood flow measurements in laser speckle flowmetry

Laser speckle flowmetry (LSF) can measure moving red blood cells in real time as changes in tissue blood flow; however, LSF values may not be sufficiently reproducible due to body movements and other factors. Therefore, it is difficult to compare absolute values of LSF directly. This study aimed to verify the influence of head fixation on improving the measurement accuracy and enabling the comparison of LSF values semi-quantitatively using an external standard. We first examined the effects of head fixation on LSF values obtained during cerebral blood flow (CBF) measurement through a bone window over the cerebrum in Sprague-Dawley rats. The LSF values in the bone window were semi-quantitated using the ratio of the external standard LSF values measured simultaneously in the same field of view in a unilateral common carotid artery ligation model to evaluate CBF. Head fixation halved the variability of LSF values when compared with measurements made without head fixation. The LSF laser focus position did not affect the LSF values provided the focus was positioned within the exposed cranium. Semi-quantitation of LSF values made it possible to monitor changes in CBF in each respective bone window over time in a model of unilateral carotid ligation. In conclusion, the stabilizing effect of head fixation on LSF values was clarified, and we observed that to improve measurement accuracy, the head should be immobilized. Semi-quantitation of LSF values was first introduced by using an external standard and appears to be useful in monitoring the CBF of each location separately.

A comparison of moist heat, dry heat, chemical dry heat and icy hot for deep tissue heating and changes in tissue blood flow.

Background: Intermittent bouts of heavy activity at greater than normal exercise intensity can cause delayed onset muscle soreness (DOMS). Several products are commercially available, all alleging to reduce DOMS. In the present investigation, 40 subjects (average age 27.0+/-4.4 years, average BMI 26.8) were assessed to determine the effect of 4 of these products on skin and muscle temperature and blood flow during 2 hours of application. These included ThermaCare Dry Heat Wraps, ThermaCare Moist Heat Wraps, Icy Hot Patches, and hydrocollator heat packs. Methods; Blood flow was measured (by laser doppler flow meter) over and in the quadriceps muscle and tissue temperature was measured (by thermistors and thermocouples) in these same areas. Results: The results of the study indicated that only ThermaCare Dry and Moist Heat Wraps both heated the muscle and increased muscle blood flow. The menthol and methyl salicylate compounds in Icy Hot cooled muscle. Skin blood flow increased 300% after the moist heat was applied after 45 minutes, low level continuous dry heat almost 256% but it took 105 minutes to reach this flow, hydrocollator heat wraps increased by 201% but only for only first 45 minutes and then back to baseline, a slight reduction in skin blood flow was seen with Icy Hot gel applied to the skin. Moist heat caused muscle temperature to increase by an average of 3.1 Deg C. Dry heat caused muscle temperature to increase by 2.2 Deg C, while hydrocollator packs increased temperature by 0.4 Deg C. Icy hot had no effect on muscle temperature. Conclusion: Continuous low level heat products had better penetration into muscle and increased blood flow the best compared to hydrocollator heat packs and Icy Hot patches.

Remifentanil infusion during desflurane anesthesia reduces tissue blood flow while maintaining blood pressure and tissue oxygen tension in the masseter muscle and mandibular bone marrow.

The aim of this study was to compare changes in tissue blood flow and tissue oxygen tension in the masseter muscle and mandibular bone marrow induced by remifentanil under desflurane or sevoflurane anesthesia. Eleven male tracheotomized Japan White rabbits were anesthetized with desflurane or sevoflurane under mechanical ventilation. The order of the inhalation of desflurane or sevoflurane was randomized. Desflurane or sevoflurane was administered at 1.0 minimum alveolar concentration and remifentanil was infused at 0.4 µg/kg/min. Observed variables included heart rate (HR), blood pressure (BP), common carotid artery blood flow (CCBF), mandibular bone marrow tissue blood flow (BBF), masseter muscle tissue blood flow (MBF), mandibular bone marrow tissue oxygen tension (PbO2), and masseter muscle tissue oxygen tension (PmO2). Two way repeated measures ANOVA showed no interaction between volatile anesthetics and remifentanil infusion except for MBF. There were significant differences in HR, SBP, DBP, MAP and CCBF between desflurane and sevoflurane groups. There were also significant differences in HR, SBP, DBP, MAP, CCBF, BBF and PbO2 before, during and after remifentanil infusion. Desflurane reduced tissue blood flow in the masseter muscle and mandibular bone marrow while better maintained HR and BP than sevoflurane. Under remifentanil infusion, although both anesthetics reduced tissue blood flow, tissue oxygen tension was maintained in masseter muscle and mandibular bone marrow.

Changes in skin microcirculation in response to low-intensity electromagnetic radiation of the millimeter range

The tissue microhemodynamics plays a significant role in a tissue homeostasis. Any pathological processes were changes in functioning of microhemodynamics. This is causes is significant interesting to safe methods for its correction. One of such methods is exposure to low-intensity electromagnetic radiation of the millimeter (MM) range, which has pronounced of biological activity. The aim of the work was to identify changes in the processes of microcirculation in human skin when exposed to a low-intensity EMR MM range (wavelength - 7.1 mm; power flux density - 0.1 mW/cm2). The study was conducted on 40 volunteer girls aged 18-20 years. The exposure of low-intensity MM radiation was carried out daily for 10 days with an exposure of 30 minutes on the area of biologically active area GI-4. Microcirculation indices were recorded by laser Doppler flowmetry both in the area of influence of MM radiation (contact point of registration) and in the symmetrical effect of the area (distant point) to detect local and systemic changes in tissue blood flow under the action of this physical factor. The results of the study revealed for the first time that when exposed to low-intensity MM radiation, local changes in tissue blood flow in the contact point area were observed, manifested in changes in myogenic and endothelial oscillatory activity, starting from the first sessions of exposure, which indicates a decrease in peripheral resistance of precapillary sphincters and an increase in secretory activity of microvascular endothelium; changes in neurogenic oscillations-starting from the third session, which is accompanied by a decrease in arteriolar resistance; changes in pulse fluctuations - during the last tenth session of exposure, which is an indication of an increase in arteriolar blood filling. These changes were maintained during the entire period of exposure to this physical factor. Systemic changes in microcirculation parameters at a distant symmetrical point during the course action of MM radiation were characterized by changes in the neurogenic oscillator component, starting from the third session of exposure, and changes in the amplitude of endothelial and pulse oscillations - during the tenth session.

Low Cost Laser Speckle Imaging System for Blood Flow Assessment

This paper aims to demonstrate the feasibility of using a low cost laser speckle imaging built for the detection of changes of tissue blood flow with different experimental conditions. Images of anterior portion of the wrist of four healthy adult volunteers illuminated by a laser source of wavelength 650 nm were collected via a monochromatic charge-coupled device (CCD) imager. The mean and standard deviation (SD) of blood flow perfusion was predicted as 3.92 ± 1.47 and 2.90 ± 1.39, respectively, for measurements at rest condition and during blood flow occlusion. This work showed the ability of the developed system to detect changes in blood flow perfusion with differences in the experimental conditions. However, further works are required to further confirm the suitability of the system before it is used for different clinical applications such as monitoring of blood flow during diabetic foot ulcers healing following standard medical treatment.

Improvements in tissue blood flow and lumbopelvic stability after lumbopelvic core stabilization training in patients with chronic non-specific low back pain.

[Purpose] This study investigated the effects of lumbopelvic stabilization training on tissue blood flow changes in the lumbopelvic region and lumbopelvic stability compared to placebo treatment and controlled intervention among patients with chronic non-specific low back pain. [Subjects and Methods] A total of 25 participants (7 males, 18 females; mean age, 33.3 ± 14.4 years) participated in this within-subject, repeated-measures, double-blind, placebo-controlled comparison trial. The participants randomly underwent three types of interventions that included lumbopelvic stabilization training, placebo treatment, and controlled intervention with 48 hours between sessions. Lumbopelvic stability and tissue blood flow were measured using a pressure biofeedback device and a laser Doppler flow meter before and after the interventions. [Results] The repeated-measures analysis of variance results demonstrated a significant increase in tissue blood flow over the lumbopelvic region tissues for post- versus pre-lumbopelvic stabilization training and compared to placebo and control interventions. A significant increase in lumbopelvic stability before and after lumbopelvic stabilization training was noted, as well as upon comparison to placebo and control interventions. [Conclusion] The current study supports an increase in tissue blood flow in the lumbopelvic region and improved lumbopelvic stability after core training among patients with chronic non-specific low back pain.

Механізми змін мікроциркуляції у щурів при гострій метгемоглобінемії

It was investigated the features of microcirculation and mechanisms it's conditioned, under acute administration of sodium nitrite in 5 mg of dry substance per 100 g of body weight. It was shown that acute administration of sodium nitrite leads to the development of methemoglobinemia, arterial and venous hypoxemia, and severe tissue hypoxia. Increase in the diffusion path O2 at methemoglobinemia is caused due to significant hyperhydratation of lung air-blood barrier and its individual layers, and is accompanied by a decrease in both components of the diffusion capacity of the lungs for oxygen: its membrane and blood components. It was revealed that the administration of sodium nitrite has a double effect, leading to inactivation of hemoglobin, as well as to microcirculatory disturbances associated primarily with changes in the regulation of vascular tone. In this initial perfusion per unit volume of tissue per time unit intrinsic for the organism defines a set of mechanisms which are responsible for changes in tissue blood flow under methemoglobinemia.

Analysis of blood flow changes in tissue under pressure in order to evaluate the formation of bedsore

Analysis of blood flow changes in tissue under pressure in order to evaluate the formation of bedsore

Simultaneous measurement of deep tissue blood flow and oxygenation using noncontact diffuse correlation spectroscopy flow-oximeter

We report a novel noncontact diffuse correlation spectroscopy flow-oximeter for simultaneous quantification of relative changes in tissue blood flow (rBF) and oxygenation (Δ[oxygenation]). The noncontact probe was compared against a contact probe in tissue-like phantoms and forearm muscles (n = 10), and the dynamic trends in both rBF and Δ[oxygenation] were found to be highly correlated. However, the magnitudes of Δ[oxygenation] measured by the two probes were significantly different. Monte Carlo simulations and phantom experiments revealed that the arm curvature resulted in a significant underestimation (~−20%) for the noncontact measurements in Δ[oxygenation], but not in rBF. Other factors that may cause the residual discrepancies between the contact and noncontact measurements were discussed, and further comparisons with other established technologies are needed to identify/quantify these factors. Our research paves the way for noncontact and simultaneous monitoring of blood flow and oxygenation in soft and vulnerable tissues without distorting tissue hemodynamics.

Effects of Compression on Muscle Tissue Oxygenation at the Onset of Exercise

The effects of compression on gastrocnemius medialis muscle oxygenation and hemodynamics during a short-term dynamic exercise was investigated in a sample of 15 male subjects (mean ± SD; age 25.8 ± 4.9 years; mass 70.6 ± 4.3 kg). Elastic compression sleeves were used to apply multiple levels of compression to the calf muscles during exercise, and noncompressive garments were used for the control condition. Tissue hemoglobin oxygen saturation was measured as the relative "tissue oxygen index" (TOI) with a near-infrared spectrometer. The recovery of TOI during exercise was determined from the slope of oxygenation recovery in a nonoccluded situation. The TOI recovery rate during the first 2 minutes of the exercise was 24% higher (p = 0.042) for the compression condition than for the control condition. A significant correlation (r = 0.61, p = 0.012) between the level of compression and the tissue oxygenation recovery during exercise was observed. Muscle energy use was determined from the rate of decline of TOI immediately upon arterial occlusion during early exercise. Muscle energy use measured during the occluded situation was not significantly influenced by compression. Based on these results, it was concluded that compression induced changes in tissue blood flow and perfusion appear to result in improved oxygenation during short-term exercise. Assuming that increased muscle oxygen availability positively influences performance, compression of muscles may enhance performance especially in sports that require repeated short bouts of exercise.

Effects of Vibrations on Gastrocnemius Medialis Tissue Oxygenation

Whole-body vibrations are known to affect muscle activity and tissue oxygenation, but some energetic aspects are still poorly understood. This study investigates the effects of whole-body vibration on gastrocnemius muscle oxygen utilization rate and tissue oxygenation dynamics during exercise. The effects of vibration on gastrocnemius medialis muscle oxygenation were investigated during a dynamic exercise on a sample of 16 active male subjects (age = 26.3 ± 5.1 yr, mass = 71.2 ± 4.8 kg (mean ± SD)). Both arterially occluded (AO) and nonoccluded (N/O) conditions were investigated. Tissue oxygenation was monitored with a near-infrared spectrometer. Oxygen utilization rate and tissue oxygenation recovery were computed as the slopes of the regression line of the oxygenation decay and recovery, respectively. A fast Fourier transform (FFT) was used to determine the frequency spectrum of the oxygen saturation data. EMG activity was monitored using bipolar EMG electrodes. A windowed root mean square analysis was used to monitor the amplitude of the EMG signal. A statistically significant increase of 15% (P < 0.05) in oxygen utilization rate was found for the vibration condition in the AO leg but not in the N/O leg. The oxygenation recovery rate for the vibration condition was 34% higher (P < 0.05) than that for the control condition. A low-frequency periodic oscillation (T ≈ 10 s) in the tissue oxygenation data was determined from the FFT spectrum. A statistically significant decrease in the oscillation frequency was noticed for the vibration condition compared with the control. Vibrations increased the oxygen utilization rate during a dynamic exercise. The oxygenation recovery rate increased with vibrations. The low-frequency oscillation of the oxygenation was attributed to the periodic changes in tissue blood flow, and this seems to be influenced by vibrations.

Long beneficial effects after lipo-prostaglandin E1 administration on the ischemic gastric tube in pigs

Lipo-prostaglandin E1 (PGE1) is a new preparation of PGE1 in which it is bound to lipids in order to slow PGE1 release and delay its rate of metabolism. We investigated how long the beneficial effects of intravenous administration of lipo-PGE1 on the ischemic gastric tube continue. The gastric tube was constructed using 15 domestic pigs under general anesthesia and saline, unmodified PGE1 and lipo-PGE1 were infused continuously at a rate of 0.05 microg/kg/min for 10 minutes. Tissue blood flow (TBF) was analyzed from before administration to 120 minutes after the end of administration. There were no obvious changes in TBF during the administration of saline. However, TBF during treatment with unmodified PGE1 and lipo-PGE1 was significantly increased to 13.1 +/- 1.3 and 13.5 +/- 1.4 mL/min/100 g, respectively (paired t-test; P < 0.01). Although TBF was significantly decreased to 8.0 +/- 1.0 mL/min/100 g on 10 minutes after the end of unmodified PGE1 administration (paired t-test; P < 0.01), it was maintained over 10 mL/min/100 g until 120 minutes in lipo-PGE1 group. Lipo-PGE1 infusion leads to the objectively measurable improvement and the prolonged action in the blood perfusion of the gastric tube in pigs.

SHEDDING LIGHT ON LIFE: OPTICAL ASSESSMENT OF MITOCHONDRIAL FUNCTION AND TISSUE VITALITY IN BIOLOGY AND MEDICINE

The involvement of mitochondrial dysfunction in various pathophysiological conditions, developed in experimental and clinical situations, is widely documented. Nevertheless, real time monitoring of mitochondrial function In-vivo is very rare. The pressing question is how the mitochondria of intact tissues behave under In-vivo conditions as compared to isolated mitochondria that had been described by Chance and Williams over 50 years ago. This subject has been recently discussed in detail (Mayevsky and Rogatsky 2007). We reviewed the subject of evaluating mitochondrial function by monitoring NADH fluorescence together with microcirculatory blood flow, Hemoglobin oxygenation and tissue reflectance. These 4 parameters represent the vitality of the tissue and could be monitored in vivo, using optical spectroscopy, in animal models as well as in clinical practice. It is a well known physiological hypothesis that, under emergency conditions, the sympathetic nervous system will give preference to the most vital organs in the body, namely the brain, heart and adrenal glands. The less vital organs, such as the skin, GI-tract, and Urethral wall, will become hypoperfused and their mitochondrial activity will be inhibited. The monitoring of the less vital organs may reveal critical tissue conditions that may manifest an early phase of body deterioration. The aim of the current presentation is to review the experimental and preliminary clinical results accumulated using a new integrated medical device – the "CritiView" which enabled, for the first time, monitoring 4 parameters from the tissue using a single optical probe. The CritiView is a computerized optical device that integrates hardware and software in order to provide real time information on tissue vitality. In preliminary clinical testing, we used a 3-way Foley catheter that includes a bundle of optical fibers enabling the monitoring of the 4 parameters, representing the vitality of the urethral wall (a less vital organ).We found that the exposure of patients to metabolic imbalances in the operation room led to changes in tissue blood flow and inhibition of mitochondrial function in the urethral wall. In conclusion, the new device "CritiView" could provide reliable, real time data on mitochondrial function and tissue vitality in experimental animals as well as in patients.

Early Antiangiogenic Activity of Bevacizumab Evaluated by Computed Tomography Perfusion Scan in Patients with Advanced Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is a highly vascularized tumor with a poor prognosis. In a phase II study that combined bevacizumab with gemcitabine and oxaliplatin in advanced HCC, we examined computed tomography perfusion (CTp) scan parameters as surrogate markers of angiogenesis after bevacizumab administration. HCC patients received bevacizumab alone i.v. at 10 mg/kg on day 1 during cycle 1. CTp scanning was performed at baseline and days 10-12 to assess changes in tissue blood flow (BF), blood volume (BV), mean transit time (MTT), and permeability surface area product (PS). Compared with baseline, a significant decrease in the estimated tumor perfusion parameters including BF, BV, and PS and an increase in MTT were seen on days 10-12 following bevacizumab administration alone. Patients with progressive disease had lower baseline MTT values and a higher percent increase following bevacizumab administration than those with stable disease or partial responses. Bevacizumab induced a significant decrease in tumor BF, BV, and PS and an increase in MTT by CTp scan in HCC. Baseline and percent change in MTT following bevacizumab administration correlated with clinical outcome, whereas BF, BV, and PS did not.

A comparison of myocardial perfusion and rejection in cardiac transplant patients

Although histological evaluation of the cardiac tissue is the current gold standard for evaluation of rejection, we hypothesized that cardiac perfusion MRI is a safe non-invasive method that correlates tissue blood flow changes with biopsy proven rejection in the cardiac transplant patient. In a retrospective study from 1984-2001, 83 patients underwent 135 MR Gd-DTPA imaging studies. In 8 patients (9%), biopsies graded 2 or higher (by ISHLT criteria) provided evidence of rejection. Patients were age and sex matched to 11 non-rejected controls for imaging analysis. Time-signal intensity curves generated for a mid-ventricle LV short axis slice during rest and adenosine stress allowed determination of myocardial blood flow (MBF, ml/min/gm). ROC curve analysis by SPSS allowed estimation of sensitivity and specificity. At rest, there was no difference in MBF between patients with prior rejection vs. those without (1.18 +/- 0.26 vs. 1.16 +/- 0.29). At stress there was a decrease in MBF for patients with prior rejection episodes (3.27 +/- 0.74) compared to no rejection (3.60 +/- 0.72), P = 0.067). The area under the ROC curve was 0.82, with specificity and sensitivity of 75% and 81%, respectively. This study suggests that perfusion MR imaging can be used in assessing the cardiac transplant patient for rejection related microvascular changes. The high specificity and sensitivity recorded from the ROC curve illustrates the potential utility of this diagnostic test for future studies.

In vivo effects of corticotropin-releasing hormone on femoral adipose tissue metabolism in women

To investigate whether i.v. injected corticotropin-releasing hormone (CRH) (1 microg/kg) has a direct effect on adipose tissue metabolism in humans. Double-blinded, placebo-controlled, crossover study. Twelve healthy normal weight female volunteers (age 20-37 years, body mass index: 22.75+/-1.33 kg/m(2)) Assessment of local generation of glycerol, and glucose in adipose tissue by microdialysis. Measurement of adipose tissue and skin blood flow by laser Doppler flowmetry. Injection of CRH acutely increases interstitial concentrations of glycerol (19.0+/-5.4%, P<0.05) and glucose (13.5+/-5.8%, P<0.05) reaching peak levels after 15 min. Plasma glycerol increases in parallel (Delta=16.7+/-5.9% after 15 min (P<0.05)), whereas plasma glucose remains unaffected. Changes in tissue blood flow do not explain interstitial metabolite alterations. Initial CRH effects on adipose tissue metabolism are short lasting and disappear after 15 min. The importance of CRH on human energy metabolism is underlined by the present in vivo study demonstrating peptidergic effects on lipolysis and glucose homeostasis in human subcutaneous adipose tissue.

Influences of AT1 receptor blockade on tissue metabolism in obese men

ANG II applied to the interstitial space influences carbohydrate and lipid metabolism in a tissue-specific fashion. Thus endogenous ANG II may have a tonic effect on tissue metabolism that could be reversed with ANG II type 1 (AT1) receptor blockade, particularly during adrenergic stimulation. We studied 14 obese men. They were treated for 10 days with the AT1 receptor blocker irbesartan or with placebo in a double-blind and crossover fashion. At the end of each treatment period, we assessed skeletal muscle and adipose tissue metabolism using the microdialysis technique. The ethanol dilution technique was applied to follow changes in tissue blood flow. Measurements were obtained at baseline and during application of incremental isoproterenol concentrations through the microdialysis catheter. Blood pressure decreased from 133 +/- 3/84 +/- 3 to 128 +/- 3/79 +/- 2 mmHg for systolic and diastolic blood, respectively (P = 0.02 and 0.006, respectively) with AT1 receptor blockade. Isoproterenol perfusion caused a dose-dependent increase in dialysate glycerol in adipose tissue and in skeletal muscle. Irbesartan slightly reduced the isoproterenol-induced glycerol response in adipose tissue (P < 0.05 by ANOVA). Ethanol ratio, interstitial glucose supply, and lactate production in adipose tissue and skeletal muscle were similar with placebo and irbesartan. We conclude that AT1 receptor blockade in obese men does not reveal a major tonic ANG II effect on interstitial glucose supply, lipolysis, or glycolysis in skeletal muscle, either at rest or during beta-adrenergic stimulation. Endogeneous ANG II may slightly increase adipose tissue lipolysis. The mechanism may promote the redistribution of triglycerides from adipose tissue toward other organs.

Beneficial Effects of Intravenous Administration of Lipo-Prostaglandin E1 on the Ischemic Gastric Tube in Pigs

Lipo-prostaglandin E1 (PGE1) is a new preparation of PGE1 in which it is bound to lipids to slow PGE1 release and delay its rate of metabolism. We investigated the change of the blood flow on impaired microcirculation of the ischemic gastric tube in pigs after saline, unmodified PGE1, and lipo-PGE1 administration. The gastric tube was constructed using 15 domestic pigs under general anesthesia, and saline, unmodified PGE1, and lipo-PGE1 were infused continuously at a rate of 0.05 microg/kg/min for 10 min. Tissue blood flow (TBF) and the serum PGE1 concentration were analyzed before administration, after administration for 10 min, and 10 min after the end of administration. There were no obvious changes in TBF during the administration of saline. However, TBF during treatment with unmodified PGE1 and lipo-PGE1 was significantly increased to 13.0 +/- 1.3 and 13.9 +/- 1.3 ml/min/100 g, respectively (paired t-test; P < 0.01). Although TBF was significantly decreased to 8.0 +/- 1.0 ml/min/100 g on 10 min after the end of unmodified PGE1 administration (paired t-test; P < 0.01), it was maintained over 10 ml/min/100 g in lipo-PGE1 group. The serum PGE1 concentration during treatment with unmodified PGE1 and lipo-PGE1 was significantly increased to 229 +/- 21 and 225 +/- 9 pg/ml (paired t-test; P < 0.01), however, it was significantly decreased to 59 +/- 5 and 131 +/- 17 pg/ml (paired t-test; P < 0.01), respectively, on 10 min after the end of administration. However, the serum PGE1 concentration in lipo-PGE1 group was significantly higher than that in unmodified PGE1 group (unpaired t-test; P < 0.01). Lipo-PGE1 infusion leads to the objectively measurable improvement and the prolonged action in the blood perfusion of the gastric tube in pigs. Therefore, treatment with lipo-PGE1 infusion can increase TBF at the anastomotic site, and it may be beneficial for preventing anastomotic leakage in boluses for a couple of times a day.