Resistance and volume changes caused by nitroprusside in the dog

1979 ◽  
Vol 237 (1) ◽  
pp. H99-H103 ◽  
Author(s):  
S. A. Rubin ◽  
G. Misbach ◽  
J. Lekven ◽  
W. W. Parmley ◽  
J. V. Tyberg
Keyword(s):  
Vascular Resistance ◽  
Right Atrial ◽  
Control Group ◽  
Base Line ◽  
Volume Changes ◽  
Pharmacologic Agent ◽  
Vascular Volume ◽  
Successive Level ◽  
Similar Decrease ◽  
Nitroprusside Infusion

Changes in vascular volume caused by a pharmacologic agent are frequently inferred rather than directly measured. We investigated the effects of nitroprusside in 8 dogs divided into 2 groups: control and splenectomized. We anesthetized the dogs using pentobarbital, and surgically prepared a veno-right atrial bypass preparation whose controlled cardiac output and external reservoir allowed measurement of both changes in vascular resistance and changes in vascular volume. In both groups, blood pressure (mean +/- SD) decreased at each successive level of nitroprusside: 114 +/- 24 mmHg (base line), 101 +/- 19 mmHg (45 microgram/min), 90 +/- 16 mmHg (90 microgram/min), 81 +/- 17 mmHg (180 microgram/min), 68 +/- 18 mmHg (360 microgram/min). Nitroprusside caused a large and similar decrease in vascular resistance in both groups. In the control group, vascular volume increased above base line 5.5 +/- 2.7, 8.3 +/- 3.2, 11.6 +/- 2.9, and 14.7 +/- 3.5 ml/kg at each successive level of nitroprusside infusion, whereas in the splenectomized group vascular volume increased above base line 0.9 +/- 0.3, 2.5 +/- 1.0, 3.3 +/- 1.1, and 4.0 +/- 1.3 ml/kg at each successive level of nitroprusside infusion, but increased significantly less than the control group. We concluded that nitroprusside decreases vascular resistance and increases vascular volume and that the spleen is the major site of changes in vascular volume caused by nitroprusside.

Transmural metabolic gradients in the normal dog left ventricle: effect of right atrial pacing

1977 ◽  
Vol 233 (2) ◽  
pp. H217-H221 ◽  
Author(s):  
T. B. Allison ◽  
J. W. Holsinger
Keyword(s):  
Right Atrial ◽  
Control Group ◽  
Base Line ◽  
Atrial Pacing ◽  
Stroke Work ◽  
Ischemic Insult ◽  
Circumflex Artery ◽  
Heart Work ◽  
Anesthetized Dogs ◽  
The Right

The effects of atrial pacing on tissue metabolite levels known to be sensitive to ischemia were examined. Anesthetized dogs were thoracotomized and a pacing electrode was sutured to the right atrium. Pacing at rates of 200 or 250 beats/min (10 animals per group) was performed for 15 min after base-line hemodynamic data had been obtained. At the end of the pacing period, a transmural biopsy was taken, frozen in liquid nitrogen, and sectioned into subepicardial, midmyocardial, and subendocardial layers. ATP, phosphocreatine, lactate, and glycogen were extracted and analyzed. Significant (P less than 0.001) transmural gradients of each of these metabolites existed in the control group. Pacing had no significant (P greater than 0.2) effect on any metabolite from layer to layer at 200 or 250 beats/min. However, indices of heart work (i.e., contractility (dP/dt), stroke work, and stroke volume) demonstrated significant reductions (P less than 0.01) due to pacing, while circumflex artery blood flow increased more than twofold (P less than 0.001) at the highest rate. These data suggest that physiologic autoregulation occurred during pacing and protected the subendocardium from stress-induced ischemic insult.

Slow phase of transvascular fluid flux reviewed

1990 ◽  
Vol 69 (2) ◽  
pp. 456-464 ◽  
Author(s):  
B. J. Hancock ◽  
K. P. Landolfo ◽  
M. Hoppensack ◽  
L. Oppenheimer
Keyword(s):  
Weight Gain ◽  
Time Course ◽  
Slow Phase ◽  
Base Line ◽  
Volume Changes ◽  
Fluid Flux ◽  
Significant Component ◽  
Rapid Weight Gain ◽  
Vascular Volume ◽  
Colorimetric Measurements

In six circuit experiments using a clinical hemofiltration device, we validated a colorimetric technique to measure transvascular volume exchange (VE). In 12 isolated excised canine left lower lobes, continuous colorimetric measurements of VE correlated well with calculations of VE from changes in microhematocrit obtained simultaneously. We introduced step increases in microvascular hydrostatic pressure (Pc) of 9 +/- 4.8 (SD) cmH2O and followed the time course of weight and continuous hematocrit changes measured colorimetrically for 40 min, after which Pc was returned to base line, while measurements were continuously obtained. This procedure was repeated for an additional 30 min. VE was calculated from the hematocrit signals and compared with the time course of the weight signal. After increases in Pc, followed by a rapid weight gain, weight signals followed a slow exponential time course, whereas the calculated VE changed linearly. VE reflected approximately 60% of the slow weight gain. When Pc was decreased, weight signals decreased exponentially, whereas VE continued to increase linearly at a slower rate. These results suggest that a significant component of the slow weight signal represents slow vascular volume changes. Contrary to what the weight signal suggested, edema was never reabsorbed over the range of Pc measured.

Role for the Endogenous Natriuretic Peptide System in the Control of Basal Coronary Vascular Tone in Dogs

1996 ◽  
Vol 90 (5) ◽  
pp. 357-362 ◽  
Author(s):  
Thanom Supaporn ◽  
Paul W. Wennberg ◽  
Chi-Ming Wei ◽  
Masahiko Kinoshita ◽  
Yuzuru Matsuda ◽  
...  
Keyword(s):  
Natriuretic Peptide ◽  
Vascular Resistance ◽  
Vascular Tone ◽  
Right Atrial ◽  
Control Group ◽  
Vascular Regulation ◽  
Significant Difference ◽  
Coronary Vascular Tone ◽  
Peptide System ◽  
Natriuretic Peptide System

1. While the natriuretic peptides (atrial, brain and C-type) mediate potent endothelium-independent vasorelaxing actions in vitro, the role of the endogenous natriuretic peptide system in vascular regulation in vivo remains unclear. 2. HS-142-1 is a novel natriuretic peptide receptor antagonist derived from a fungus named Aureobasidium sp. which selectively blocks particulate guanylate cyclase-linked natriuretic peptide A and B receptors that bind atrial, brain and C-type natriuretic peptide, and thus attenuates the generation of cGMP. 3. To characterize the vascular actions of the endogenous natriuretic peptide system in the control of basal coronary and systemic haemodynamics, six normal male mongrel anaesthetized dogs were studied while a second group of five dogs served as a control. HS-142-1 was given as an intravenous bolus at 3 mg/kg and was studied over five 20 min periods. 4. No significant difference after HS-142-1 was observed in mean arterial pressure, heart rate, cardiac output, right atrial pressure, pulmonary capillary wedge pressure or systemic vascular resistance compared with control. In contrast, a significant increase in coronary vascular resistance and decrease in coronary blood flow were observed which were different from the baseline values and the responses of the control group. 5. These studies demonstrate that HS-142-1 produces vasoconstriction in the coronary circulation. We conclude that the endogenous natriuretic peptide system, which is of cardiac and endothelial cell origin, is an important regulator of basal coronary vascular tone.

Cardiovascular adaptation of newborn lambs to hypervolemia with polycythemia

1970 ◽  
Vol 48 (5) ◽  
pp. 312-320 ◽  
Author(s):  
Jean-Claude Fouron ◽  
Francine Hébert
Keyword(s):  
Blood Volume ◽  
Ductus Arteriosus ◽  
Right Atrial ◽  
Control Group ◽  
Base Line ◽  
Progressive Reduction ◽  
Fick Principle ◽  
Acute Increase ◽  
Left And Right ◽  
Line Level

Hemodynamic studies were carried out in five newborn lambs before, during, and for a period of 3 h after an increase of approximately 50% in blood volume. Four other animals served as a control group. The animals were delivered by cesarean less than 1 week before the anticipated date of birth. Pressures were continuously recorded in aorta, pulmonary artery, and right and left atrium. Pulmonary and systemic flows as well as the possible shunts through the ductus arteriosus and the foramen ovale were calculated according to the Fick principle. The results showed a marked increase in systemic flows, followed by a progressive reduction but no return to the base-line level, closure of the ductus arteriosus during or shortly after the infusion, and a transient systemic and pulmonary hypertension associated with a marked elevation in left and right atrial pressures. No change was observed in the cardiac rhythm or the O2 consumption. These data suggest that the venous vascular bed of newborn lambs is less able than that of adult animals to cope with an acute increase in blood volume.

Melatonin Improves Erythropoietin Hyporesponsiveness via Suppression of Inflammation

2019 ◽  
Vol 14 (3) ◽  
pp. 203-208
Author(s):  
Evan Noori Hameed ◽  
Haydar F. Hadi AL Tukmagi ◽  
Hayder Ch Assad Allami
Keyword(s):  
Iron Status ◽  
Transferrin Saturation ◽  
Control Group ◽  
Base Line ◽  
Inadequate Response ◽  
Inflammatory Parameters ◽  
Tnf Α ◽  
Before And After ◽  
And Control ◽  
Controlled Clinical Study

Background: Inadequate response to Erythropoietin Stimulating Agents (ESA) despite using relatively larger doses regimen represents a potential risk factor of Cardiovascular (CV) related mortality in addition to health-care economic problems in anemic patients with Chronic Kidney Disease (CKD). Erythropoietin (EPO) hyporesponsiveness related to inflammation has been increased progressively. Melatonin is well known as a potent anti-inflammatory agent. Therefore, the current study was designed to evaluate whether melatonin could improve anemic patients response to EPO. Methods: This single controlled clinical study was carried out in 41 CKD patients with hemoglobin (Hb) levels less than 11g/dl divided randomly in a 1:1 ratio into 2 groups; treatment group who received 5mg melatonin plus their regular treatments and control group who received their regular treatments only. Hematological and iron status parameters include Hb level, serum iron (S. iron), Transferrin Saturation Ratio (TSAT) and serum ferritin (S. ferritin) in addition to inflammatory parameters that include tissue necrotic factor alfa (TNF-α), interleukin-1beta (IL-1β) and interleukin-6 (IL-6) determined before and after 12 weeks of treatment. Results: Melatonin remarkably increases the Hb level with a significant increase in S. iron and TSAT compared to baseline. The elevation of S. iron and TSAT was significantly higher in the melatonin group. Additionally, all inflammatory markers estimated were reduced significantly by melatonin compared to base line and control group. Conclusion: The results of the current study showed that melatonin has an advantageous effect on improving EPO response in anemic patients with CKD.

scholarly journals P946 Right atrial volumetric and functional analysis by three-dimensional speckle-tracking echocardiography in acromegaly

2020 ◽  
Vol 21 (Supplement_1) ◽  
Author(s):  
A Kormanyos ◽  
A Kalapos ◽  
P Domsik ◽  
N Gyenes ◽  
N Ambrus ◽  
...  
Keyword(s):  
Speckle Tracking ◽  
Speckle Tracking Echocardiography ◽  
Three Dimensional ◽  
Radial Strain ◽  
Human Growth ◽  
Active Phase ◽  
Right Atrial ◽  
Control Group ◽  
Cardiovascular Comorbidities ◽  
Atrial Contraction

Abstract Introduction Acromegaly is a chronic, rare hormonal disease associated with major cardiovascular comorbidities. The disease, in the majority of the cases, is caused by a benign human growth hormone secreting adenoma. Cardiovascular involvement is especially common in acromegaly patients from the most common hypertension to cardiomyopathy. It was set out to quantify right atrial (RA) morphology and function in a group of acromegaly patients using three-dimensional (3D) speckle-tracking echocardiography (3DSTE). Methods The study comprised 30 patients from which 8 patients were excluded due to inadequate image quality. Mean age of the remaining acromegaly patients were 53.7 ± 14.5 years (7 males). Ten patients were in active phase, while 12 subjects had inactive acromegaly. In the control group 40 healthy adults were enrolled (mean age: 52.3 ± 8.2 years, 15 males). In each case, complete two-dimensional Doppler echocardiography was performed followed by 3DSTE. Results Maximum (54.5 ± 14.4 ml vs. 47.2 ± 11.6 ml, p <0.05) and minimum (35.5 ± 10.2 ml vs. 29.2 ± 9.1 ml, p <0.05) RA volumes and RA volume before atrial contraction (45.1 ± 11.1 ml vs. 38.2 ± 10.3 ml, p <0.05) were significantly higher in case of acromegaly compared to the healthy controls. Both global and mean segmental peak 3D strain (-11.94 ± 7.52% vs. -8.07 ± 5.03%, p <0.05 and -17.16 ± 6.13% vs. -13.78 ± 5.35%, p <0.05) were higher in the acromegaly group compared to the controls. At atrial contraction, mean segmental radial strain (-13.22 ± 6.45% vs. -9.74 ± 4.58%, p <0.05) was significantly higher and mean segmental 3D strain (-9.78 ± 5.44% vs. -13.78 ± 5.35%, p <0.05) was significantly lower in the acromegaly group compared to the controls. Between the active and inactive group of acromegaly patients, mean segmental longitudinal strain (28.17 ± 4.89% vs. 35.34 ± 9.75%, p <0.05) was significantly different. Numerous independent strain parameters had significant correlations with different hormonal variables in the active acromegaly group. These correlations were not present in the inactive acromegaly subgroup. Conclusion Acromegaly is associated with significant RA volumetric and functional abnormalities.

The Effect of Fluoxetine and Ibuprofen on BCG-Induced Alteration in Pain Sensitivity in Mice

QJM ◽  
2021 ◽  
Vol 114 (Supplement_1) ◽  
Author(s):  
Heba H El-Morsy ◽  
Wesam El-Bakly ◽  
Amany H Hasanin ◽  
May Hamza ◽  
M Abdel-Bary
Keyword(s):  
Drinking Water ◽  
Mechanical Allodynia ◽  
Formalin Test ◽  
Forced Swim Test ◽  
Tail Suspension Test ◽  
Control Group ◽  
Base Line ◽  
Immobility Time ◽  
Long Time ◽  
Incisional Pain

Abstract Clinical observations recognized the co-existence and interactions of pain and depression a long time, ago. The aim of this work was to study the effect of ibuprofen and fluoxetine on BCGinduced depressive-like behaviour, on formalin-induced pain, as well as on mechanical allodynia after planter incision in mice. BCG induced a depressive behaviour that was seen in the forced swim test (FST) and the tail suspension test (TST). It also induced a decrease in pain-related behaviour in the formalin test, and an increase in the baseline in mechanical allodynia test compared to the control group. Fluoxetine (80 mg/L of drinking water) showed a significant decrease in the immobility time in the FST and TST and enhanced pain related behaviour in formalin test in the BCG-inoculated group. However, it did not affect the increase in the pain threshold in the planter incision allodynia model. Adding ibuprofen to drinking water (0.2 g/L of drinking water), reversed the depressive like behaviour induced by BCG and enhanced pain-related behaviour in formalin test, in both the total pain-related behaviour and phase 2. It also prevented the increase in the base line induced by BCG. On the other hand, the incisional pain model was not affected by BCG inoculation except at the 2-hour time point, where it showed hypoalgesia, as well.

Derecruitment of filtration surface area in paraquat-injured isolated dog lungs

1990 ◽  
Vol 68 (4) ◽  
pp. 1581-1589 ◽  
Author(s):  
T. Shibamoto ◽  
J. C. Parker ◽  
A. E. Taylor ◽  
M. I. Townsley
Keyword(s):  
Blood Flow ◽  
Surface Area ◽  
Vascular Resistance ◽  
High Flow ◽  
Base Line ◽  
Flow Rates ◽  
Blood Flows ◽  
Capillary Filtration Coefficient ◽  
Specific Index ◽  
Filtration Surface

The capillary filtration coefficient (Kf,c) is a sensitive and specific index of vascular permeability if surface area remains constant, but derecruitment might affect Kf,c in severely damaged lungs with high vascular resistance. We studied the effect of high and low blood flow rates on Kf,c in papaverine-pretreated blood-perfused isolated dog lungs perfused under zone 3 conditions with and without paraquat (PQ, 10(-2) M). Three Kf,cs were measured successively at hourly intervals for 5 h. These progressed sequentially from isogravimetric blood flow with low vascular pressure (I/L) to high flow with low vascular pressure (H/L) to high flow with high vascular pressure (H/H). The blood flows of H/L and H/H were greater than or equal to 1.5 times that of I/L. There were no significant changes in Kf,c in lungs without paraquat over a 50-fold range of blood flow rates. At 3 h after PQ, I/L-Kf,c was significantly increased and both isogravimetric capillary pressure and total protein reflection coefficient were decreased from base line. At 4 and 5 h, H/L-Kf,c was significantly greater than the corresponding I/L-Kf,c (1.01 +/- 0.22 vs. 0.69 +/- 0.09 and 1.26 +/- 0.19 vs. 0.79 +/- 0.10 ml.min-1.cmH2O-1.100 g-1, respectively) and isogravimetric blood flow decreased to 32.0 and 12.0% of base line, respectively. Pulmonary vascular resistance increased to 12 times base line at 5 h after PQ. We conclude that Kf,c is independent of blood flow in uninjured lungs. However, Kf,c measured at isogravimetric blood flow underestimated the degree of increase in Kf,c in severely damaged and edematous lungs because of a high vascular resistance and derecruitment of filtering surface area.

Measurement of mean circulatory filling pressure and vascular compliance in domestic pigs

1990 ◽  
Vol 258 (6) ◽  
pp. H1925-H1932 ◽  
Author(s):  
R. I. Ogilvie ◽  
D. Zborowska-Sluis ◽  
B. Tenaschuk
Keyword(s):  
Cardiac Arrest ◽  
Circulatory Arrest ◽  
Filling Pressure ◽  
Right Atrial ◽  
Base Line ◽  
Pentobarbital Sodium ◽  
Closed Chest ◽  
Mean Circulatory Filling Pressure ◽  
Vascular Compliance ◽  
Venous Circulation

To measure mean circulatory filling pressure (Pmcf), a balloon was placed in the right atrium of seven pentobarbital sodium-anesthetized open-chest pigs for transient occlusion of flow combined with mechanical transfer of blood from the arterial to the venous circulation. Equilibration occurred within 6-8 s at a pressure at 12.3 +/- 0.3 (SE) mmHg after a 2.9 +/- 0.2 ml/kg transfer of blood. In another group of pentobarbital sodium-anesthetized closed-chest pigs, acetylcholine (ACh) was used to induce cardiac arrest. The Pmcf was 11.6 +/- 1.0 mmHg in the 7:17 pigs that arrested for 6-8 s. In four isoflurane-anesthetized closed-chest pigs, the Pmcf was 12.0 +/- 1.0 mmHg after terminal cardiac arrest induced by KCl. The pressure gradient for venous return [Pmcf--right atrial pressure (Pra)] averaged 5.9 +/- 0.2 mmHg. Total vascular compliance estimated from plots of Pmcf at base line, 5, and 10 ml/kg increases in circulating volume was 2.1 +/- 0.3 and 3.5 +/- 0.9 ml.kg-1.mmHg-1 in the balloon and ACh groups, respectively compared with 2.8 +/- 0.4 ml.kg-1.mmHg-1 using a volume infusion-withdrawal method without circulatory arrest. The use of ACh for the estimate of Pmcf in the pig is not recommended because of failure to consistently induce circulatory arrest and probable failure to achieve sufficient equilibrium of vascular pressures 6-8 s postarrest when it occurs.

scholarly journals Volume rendered 3D OCTA assessment of macular ischemia in patients with type 1 diabetes and without diabetic retinopathy

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Enrico Borrelli ◽  
Domenico Grosso ◽  
Mariacristina Parravano ◽  
Eliana Costanzo ◽  
Maria Brambati ◽  
...  
Keyword(s):  
Type 1 Diabetes ◽  
Diabetic Retinopathy ◽  
Healthy Subjects ◽  
Diabetic Group ◽  
Control Group ◽  
Diabetic Patients ◽  
Vascular Volume ◽  
Patients With Diabetes ◽  
Perfusion Density

AbstractThe aim of this study was to measure macular perfusion in patients with type 1 diabetes and no signs of diabetic retinopathy (DR) using volume rendered three-dimensional (3D) optical coherence tomography angiography (OCTA). We collected data from 35 patients with diabetes and no DR who had OCTA obtained. An additional control group of 35 eyes from 35 healthy subjects was included for comparison. OCTA volume data were processed with a previously presented algorithm in order to obtain the 3D vascular volume and 3D perfusion density. In order to weigh the contribution of different plexuses’ impairment to volume rendered vascular perfusion, OCTA en face images were binarized in order to obtain two-dimensional (2D) perfusion density metrics. Mean ± SD age was 27.2 ± 10.2 years [range 19–64 years] in the diabetic group and 31.0 ± 11.4 years [range 19–61 years] in the control group (p = 0.145). The 3D vascular volume was 0.27 ± 0.05 mm3 in the diabetic group and 0.29 ± 0.04 mm3 in the control group (p = 0.020). The 3D perfusion density was 9.3 ± 1.6% and 10.3 ± 1.6% in diabetic patients and controls, respectively (p = 0.005). Using a 2D visualization, the perfusion density was lower in diabetic patients, but only at the deep vascular complex (DVC) level (38.9 ± 3.7% in diabetes and 41.0 ± 3.1% in controls, p = 0.001), while no differences were detected at the superficial capillary plexus (SCP) level (34.4 ± 3.1% and 34.3 ± 3.8% in the diabetic and healthy subjects, respectively, p = 0.899). In conclusion, eyes without signs of DR of patients with diabetes have a reduced volume rendered macular perfusion compared to control healthy eyes.

Sign in / Sign up

Export Citation Format

Share Document