Cardiac output distribution in thermally dehydrated rodents

The effect of thermal dehydration (37 degrees C) on the integrated response of the circulation was studied in conscious laboratory rats and in the desert species Psammomys obesus, the latter being studied prior to and following acclimation to heat. Cardiac output (CO) and its distribution were measured using labeled microspheres with the reference organ technique. At low dehydration (7-9% body wt loss) rats showed peripheral vasodilation coincidentally with splanchnic vasoconstriction, whereas the desert species exhibited an increased CO and peripheral vasodilation with no change in splanchnic blood perfusion. At severe dehydration (10-18% body wt loss), closure of skin arteriovenous anastomoses together with splanchnic vasodilation was observed in both species. These changes were discussed in relation to plasma volume conservation mechanism and its deterioration. Acclimation to heat resulted in no change in CO, whereas blood flow to splanchnic and skin capillaries increased remarkably. Dehydration in heat-acclimated P. obesus (5-10% body wt loss) brought about a significant fall in CO. However, most organs maintained relatively stable blood flow. This might contribute to better survival during heat stress.

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Effects of Donitriptan on Carotid Haemodynamics and Cardiac Output Distribution in Anaesthetized Pigs

Cephalalgia ◽

10.1046/j.1468-2982.2002.00308.x ◽

2002 ◽

Vol 22 (1) ◽

pp. 37-47 ◽

Cited By ~ 8

Author(s):

B Tom ◽

P De Vries ◽

JPC Heiligers ◽

EW Willems ◽

K Kapoor ◽

...

Keyword(s):

Blood Flow ◽

Cardiac Output ◽

Skeletal Muscles ◽

Selective Reduction ◽

Receptor Activation ◽

Haemodynamic Effects ◽

Maximum Response ◽

Arteriovenous Anastomoses ◽

Vascular Conductance ◽

Migraine Headaches

We investigated the effects of donitriptan, which possesses a uniquely high affinity and efficacy at 5-HT1B/1D receptors, on carotid and systemic haemodynamics in anaesthetized pigs. Donitriptan (0.16-100 μg kg-1, i.v.) dose-dependently decreased total carotid blood flow and vascular conductance (maximum response: -25 ± 3%). This effect was entirely due to a selective reduction in the cephalic arteriovenous anastomotic fraction (maximum response: -63 ± 3%; ED50%: 92 ± 31 nmol/kg); the nutrient vascular conductance increased. Donitriptan did not decrease vascular conductances in or blood flow to a number of organs, including the heart and kidneys; in fact, vascular conductances in the skin, brain and skeletal muscles increased. Cardiac output was slightly decreased by donitriptan, but this effect was confined to peripheral arteriovenous anastomoses. The haemodynamic effects of donitriptan were substantially reduced by the 5-HT1B/1D receptor antagonist GR127935. These results show that donitriptan selectively constricts arteriovenous anastomoses via 5-HT1B receptor activation. The drug should be able to abort migraine headaches and it is unlikely to compromize blood flow to vital organs.

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Baroreflex participation in redistribution of cardiac output at onset of exercise

Journal of Applied Physiology ◽

10.1152/jappl.1988.64.2.627 ◽

1988 ◽

Vol 64 (2) ◽

pp. 627-634 ◽

Cited By ~ 27

Author(s):

J. R. Hales ◽

J. Ludbrook

Keyword(s):

Blood Flow ◽

Cardiac Output ◽

Cardiac Muscle ◽

Treadmill Exercise ◽

Arteriovenous Anastomoses ◽

Vascular Conductance ◽

Conscious Animal ◽

Vascular Beds ◽

Increased Blood Flow ◽

Distribution Of Cardiac Output

The distribution of cardiac output and systemic vascular conductance was measured in five rabbits. Cardiac output was measured by ascending aortic flowmetry and was partitioned according to the distribution of 15-micron radiolabeled microspheres injected into the left atrium. The rabbits were studied under four conditions: at rest and after 20 s of treadmill exercise, both before and approximately 5 min after acute barodenervation of the conscious animal. During exercise in the baroinnervated state, approximately 40% of the increased blood flow to skeletal and cardiac muscle was contributed by diversion from the splanchnic organs, kidneys, systemic arteriovenous anastomoses, and skin. This diversion of blood flow during exercise was absent after arterial barodenervation. We conclude that at the onset of exercise in rabbits the mismatch between cardiac output and the metabolic demands of skeletal and cardiac muscle is accommodated by vasoconstriction in other vascular beds. We suggest that the vasoconstriction in the splanchnic organs and skin may be caused by transient suppression of the reflex effects of arterial baroreceptor input at the onset of exercise.

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Body, eye, and chorioallantoic vessel growth are not dependent on cardiac output level in day 3–4 chicken embryos

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.00086.2004 ◽

2004 ◽

Vol 287 (6) ◽

pp. R1399-R1406 ◽

Cited By ~ 14

Author(s):

Warren Burggren ◽

Sheva Khorrami ◽

Alan Pinder ◽

Tiffany Sun

Keyword(s):

Blood Flow ◽

Cardiac Output ◽

Body Mass ◽

Chorioallantoic Membrane ◽

Blood Perfusion ◽

Ventricular Outflow Tract ◽

Tissue Growth ◽

Wide Range ◽

Vessel Growth ◽

Eye Diameter

Normal aerobic metabolic rates persist in the early chicken embryo after elimination of cardiac output, but the dependence of tissue growth and differentiation on blood flow is unknown in these early stages. We partially ligated (25–50% occlusion) the ventricular outflow tract of Hamburger-Hamilton stage (HH) 16–18 embryos, producing a wide range of cardiac output. For the next ∼48 h (to HH 24), we measured heart rate (HR), stroke volume (SV), and cardiac output (CO), as well as these growth indicators: eye diameter, chorioallantoic vessel density, and body mass. Acutely, HR declined with partial ligation (from 108 to 98 beats/min). Paradoxically, SV and CO decreased sharply in most embryos but increased in others, collectively producing the desired large variation (up to 25-fold) in CO and permitting assessment of tissue growth over a very large range of blood perfusion. Eye diameter doubled (from 0.6 to 1.2 mm) with development from HH 16 to HH 24, but within a developmental cohort there was no significant correlation between eye diameter and CO over a 25-fold range of CO. Similarly, chorioallantoic membrane vessel index was independent of CO over the CO range at all stages. Finally, body mass increase during development was not significantly affected by partial conal truncal ligation. Collectively, these data suggest that normal eye and vessel growth and body mass accumulation occur independent of their rate of blood perfusion, supporting the hypothesis of prosynchronotropy—that the heart begins to beat and generate blood flow in advance of the actual need for convective blood flow to tissues.

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Increased cardiac output, not pulmonary artery systolic pressure, increases blood flow through intrapulmonary arteriovenous anastomoses and impairs pulmonary gas exchange efficiency (717.2)

The FASEB Journal ◽

10.1096/fasebj.28.1_supplement.717.2 ◽

2014 ◽

Vol 28 (S1) ◽

Author(s):

Jonathan Elliott ◽

Joseph Duke ◽

Joel Futral ◽

Randall Goodman ◽

Jerold Hawn ◽

...

Keyword(s):

Blood Flow ◽

Cardiac Output ◽

Gas Exchange ◽

Pulmonary Artery ◽

Systolic Pressure ◽

Pulmonary Gas Exchange ◽

Pulmonary Artery Systolic Pressure ◽

Arteriovenous Anastomoses ◽

Flow Through

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CARDIAC OUTPUT AND RENAL BLOOD-FLOW IN SEVERE DEHYDRATION

The Lancet ◽

10.1016/s0140-6736(58)90368-4 ◽

1958 ◽

Vol 272 (7047) ◽

pp. 644 ◽

Cited By ~ 2

Author(s):

P. Bálint ◽

J. Sturcz

Keyword(s):

Blood Flow ◽

Cardiac Output ◽

Renal Blood Flow ◽

Severe Dehydration

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Diastolic pressure and peripheral resistance during stellate ganglion stimulation

American Journal of Physiology-Legacy Content ◽

10.1152/ajplegacy.1963.204.1.71 ◽

1963 ◽

Vol 204 (1) ◽

pp. 71-72 ◽

Cited By ~ 1

Author(s):

Edward D. Freis ◽

Jay N. Cohn ◽

Thomas E. Liptak ◽

Aristide G. B. Kovach

Keyword(s):

Heart Rate ◽

Blood Flow ◽

Cardiac Output ◽

Total Peripheral Resistance ◽

Diastolic Pressure ◽

Stellate Ganglion ◽

Peripheral Resistance ◽

Resistance Vessels ◽

Left Stellate Ganglion ◽

Increased Blood Flow

The mechanism of the diastolic pressure elevation occurring during left stellate ganglion stimulation was investigated. The cardiac output rose considerably, the heart rate remained essentially unchanged, and the total peripheral resistance fell moderately. The diastolic rise appeared to be due to increased blood flow rather than to any active changes in resistance vessels.

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The use of pulse pressure variation for predicting impairment of microcirculatory blood flow

Scientific Reports ◽

10.1038/s41598-021-88458-3 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Christoph R. Behem ◽

Michael F. Graessler ◽

Till Friedheim ◽

Rahel Kluttig ◽

Hans O. Pinnschmidt ◽

...

Keyword(s):

Blood Flow ◽

Cardiac Output ◽

Reperfusion Injury ◽

Pulse Pressure ◽

Pulse Pressure Variation ◽

Ischemia Reperfusion Injury ◽

Ischemia Reperfusion ◽

Pressure Variation ◽

Volume Loading ◽

Microcirculatory Blood Flow

AbstractDynamic parameters of preload have been widely recommended to guide fluid therapy based on the principle of fluid responsiveness and with regard to cardiac output. An equally important aspect is however to also avoid volume-overload. This accounts particularly when capillary leakage is present and volume-overload will promote impairment of microcirculatory blood flow. The aim of this study was to evaluate, whether an impairment of intestinal microcirculation caused by volume-load potentially can be predicted using pulse pressure variation in an experimental model of ischemia/reperfusion injury. The study was designed as a prospective explorative large animal pilot study. The study was performed in 8 anesthetized domestic pigs (German landrace). Ischemia/reperfusion was induced during aortic surgery. 6 h after ischemia/reperfusion-injury measurements were performed during 4 consecutive volume-loading-steps, each consisting of 6 ml kg−1 bodyweight−1. Mean microcirculatory blood flow (mean Flux) of the ileum was measured using direct laser-speckle-contrast-imaging. Receiver operating characteristic analysis was performed to determine the ability of pulse pressure variation to predict a decrease in microcirculation. A reduction of ≥ 10% mean Flux was considered a relevant decrease. After ischemia–reperfusion, volume-loading-steps led to a significant increase of cardiac output as well as mean arterial pressure, while pulse pressure variation and mean Flux were significantly reduced (Pairwise comparison ischemia/reperfusion-injury vs. volume loading step no. 4): cardiac output (l min−1) 1.68 (1.02–2.35) versus 2.84 (2.15–3.53), p = 0.002, mean arterial pressure (mmHg) 29.89 (21.65–38.12) versus 52.34 (43.55–61.14), p < 0.001, pulse pressure variation (%) 24.84 (17.45–32.22) versus 9.59 (1.68–17.49), p = 0.004, mean Flux (p.u.) 414.95 (295.18–534.72) versus 327.21 (206.95–447.48), p = 0.006. Receiver operating characteristic analysis revealed an area under the curve of 0.88 (CI 95% 0.73–1.00; p value < 0.001) for pulse pressure variation for predicting a decrease of microcirculatory blood flow. The results of our study show that pulse pressure variation does have the potential to predict decreases of intestinal microcirculatory blood flow due to volume-load after ischemia/reperfusion-injury. This should encourage further translational research and might help to prevent microcirculatory impairment due to excessive fluid resuscitation and to guide fluid therapy in the future.

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Diagnosis of Fibrotic Distal Ileum Stenosis after Ischemic Enteritis Using Transabdominal Ultrasonography

Case Reports in Gastroenterology ◽

10.1159/000516852 ◽

2021 ◽

pp. 568-577

Author(s):

Ryo Katsumata ◽

Noriaki Manabe ◽

Masaki Matsubara ◽

Jun Nakamura ◽

Kazuma Kawahito ◽

...

Keyword(s):

Blood Flow ◽

Case Reports ◽

Blood Perfusion ◽

Distal Ileum ◽

Wall Thickening ◽

Current Case ◽

Abdominal Ultrasonography ◽

Transabdominal Ultrasonography ◽

Stenotic Lesion ◽

Ischemic Enteritis

Ischemic enteritis (IE) is a rare disorder which is caused by inadequate blood flow to small intestine. The diagnostic procedure of this disease has not sufficiently established because of its rarity. Here, we report a case of IE in a hemodialysis-dependent 70-year-old man and summarize the diagnostic options for IE. The patient was admitted to our hospital because of acute abdominal distention and vomiting. He presented with mild tenderness in the lower abdomen and slightly elevated C-reactive protein level as revealed by blood tests. Radiographic imaging showed small bowel obstruction due to a stricture in the distal ileum. Contrast-enhanced abdominal ultrasonography revealed a 7-cm stenotic site with increased intestinal wall thickening, which preserved mucosal blood perfusion. Elastography revealed a highly elastic alteration of the stenotic lesion, indicating benign fibrotic changes resulting from chronic insufficient blood flow. Based on a clinical diagnosis of IE with fibrous stenosis, a partial ileostomy was performed. After surgical treatment, oral intake was initiated without recurrence of intestinal obstruction. Pathological findings revealed deep ulceration with inflammatory cell infiltration at the stenotic site. Occlusion and hyalinization of the venules in the submucosal layer indicated IE. In addition to current case, we reviewed past case reports of IE. Through this case presentation and literature review, we summarize the usefulness and safety of transabdominal ultrasonography for diagnosing IE.

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