Organ blood flow in response to infusion of arginine vasopressin in premature fetal sheep

2020 ◽  
Vol 62 (6) ◽  
pp. 688-693
Author(s):  
Shimpei Watanabe ◽  
Tadashi Matsuda ◽  
Takushi Hanita ◽  
Hideyuki Ikeda ◽  
Shouta Koshinami ◽  
...  
Keyword(s):  
Blood Flow ◽  
Arginine Vasopressin ◽  
Organ Blood Flow ◽  
Fetal Sheep

Effect of 1-deamini-6-carba-(8-arginine)-vasopressin on organ blood flow in the female guinea pig

1977 ◽  
Vol 46 (1) ◽  
pp. 25-30 ◽  
Author(s):  
Per-Ove B. Sjöquist ◽  
Leif Bjellin ◽  
Anthony M. Carter
Keyword(s):  
Blood Flow ◽  
Guinea Pig ◽  
Arginine Vasopressin ◽  
Organ Blood Flow

Control of organ blood flow in fetal sheep during normoxia and hypoxia

1989 ◽  
Vol 257 (4) ◽  
pp. H1132-H1139 ◽  
Author(s):  
A. H. Jansen ◽  
J. Belik ◽  
S. Ioffe ◽  
V. Chernick
Keyword(s):  
Blood Flow ◽  
Rem Sleep ◽  
Skeletal Muscles ◽  
Nrem Sleep ◽  
Adaptation To Hypoxia ◽  
Organ Blood Flow ◽  
Fetal Sheep ◽  
Blood Flows ◽  
Carotid Bodies ◽  
Fetal Breathing

The role of peripheral chemoreceptors in the circulatory adaptation to hypoxia and the effects of rapid-eye-movement (REM) and non-REM (NREM) sleep and breathing activity on organ blood flow were assessed in fetal sheep. Blood flow was measured with isotope-labeled microspheres on intact, vagotomized (VX), and sinoaortic-denervated (SAD) fetuses. Denervation did not change the biventricular cardiac output (Biv. CO) or organ blood flows during normoxia. In intact fetuses the blood flow was increased during hypoxemia in brain, adrenals, and heart but not in kidneys, skeletal muscles, or placenta. The increase in organ blood flow during hypoxemia was reduced in the VX group and even more in SAD fetuses, but in the latter group, blood flow was still increased in mid-brain, medulla, pons, skeletal muscles, and heart. Sleep states per se did not significantly affect the blood flow to any organs tested. However, the Biv. CO and blood flow to all organs except kidneys and adrenals was increased during fetal breathing in REM sleep. We conclude that 1) during moderate hypoxemia both aortic and carotid bodies plus an additional mechanism are involved in redistributing fetal blood flow, and 2) changes in organ perfusion during REM sleep are due to concomitant fetal breathing.

Nitric Oxide and Fetal Organ Blood Flow During Normoxia and Hypoxemia in Endotoxin-Treated Fetal Sheep

2005 ◽  
Vol 105 (1) ◽  
pp. 145-155 ◽  
Author(s):  
Audrey B. C. Coumans ◽  
Yves Garnier ◽  
Sirma Supçun ◽  
Arne Jensen ◽  
Richard Berger ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Blood Flow ◽  
Organ Blood Flow ◽  
Fetal Sheep ◽  
Fetal Organ

Hemodynamics and organ blood flow in fetal sheep subjected to chronic anemia

1991 ◽  
Vol 261 (6) ◽  
pp. R1542-R1548 ◽  
Author(s):  
L. E. Davis ◽  
A. R. Hohimer
Keyword(s):  
Blood Flow ◽  
Hydrostatic Pressure ◽  
Venous Pressure ◽  
Arterial Oxygen ◽  
Organ Blood Flow ◽  
Fetal Sheep ◽  
Chronic Anemia ◽  
Arterial Oxygen Content ◽  
Extravascular Fluid ◽  
Arterial Ph

To investigate cardiovascular adaptation to chronic anemia we studied eight ovine fetuses made anemic by serial isovolemic hemorrhage and seven nonanemic controls. After 1 wk carotid arterial oxygen content was reduced to 1.6 +/- 0.2 ml/dl and hematocrit to 13.3 +/- 1.6% in anemic fetuses compared with 6.9 +/- 1.2 ml/dl and 32.4 +/- 3.9% in controls. Cardiac output was higher in the anemic group (753 +/- 102 vs. 490 +/- 66 ml.min-1.kg fetus-1) as stroke volume and heart rate both increased. Blood flow to the carcass, skin, kidneys, intestines, brain, and heart was increased. Vascular resistance fell in all tissues except the placenta. Central venous pressure, arterial pH, plasma total protein, and blood volume were not different although extravascular fluid accumulated in six of the anemic fetuses. The estimated capillary hydrostatic pressure was greater in anemic (7.6 +/- 1.8 mmHg) than control fetuses (5.0 +/- 1.5 mmHg) and the ratio of precapillary to postcapillary resistance was less. We conclude that reduction in the ratio of precapillary to postcapillary resistance in chronic fetal anemia increases blood flow, oxygen delivery, and capillary hydrostatic pressure.

Effects of betamethasone (βM) on adrenal blood flow in fetal sheep

1998 ◽  
Vol 5 (1) ◽  
pp. 156A-156A
Author(s):  
M SCHWAB ◽  
M ROEDEL ◽  
L BUCHWALDER ◽  
B WALTHER ◽  
P NATHANIELSZ
Keyword(s):  
Blood Flow ◽  
Fetal Sheep

Behavioral activity during prolonged hypoxemia in fetal sheep

1988 ◽  
Vol 65 (6) ◽  
pp. 2420-2426 ◽  
Author(s):  
A. D. Bocking ◽  
R. Gagnon ◽  
K. M. Milne ◽  
S. E. White
Keyword(s):  
Blood Flow ◽  
Eye Movements ◽  
Normal Incidence ◽  
Behavioral Activity ◽  
Uterine Blood Flow ◽  
Fetal Sheep ◽  
Pregnant Sheep ◽  
Fetal Breathing ◽  
Fetal Breathing Movements ◽  
Internal Iliac

Experiments were conducted in unanesthetized, chronically catheterized pregnant sheep to determine the fetal behavioral response to prolonged hypoxemia produced by restricting uterine blood flow. Uterine blood flow was reduced by adjusting a vascular occluder placed around the maternal common internal iliac artery to decrease fetal arterial O2 content from 6.1 +/- 0.3 to 4.1 +/- 0.3 ml/dl for 48 h. Associated with the decrease in fetal O2 content, there was a slight increase in fetal arterial PCO2 and decrease in pH, which were both transient. There was an initial inhibition of both fetal breathing movements and eye movements but no change in the pattern of electrocortical activity. After this initial inhibition there was a return to normal incidence of both fetal breathing movements and eye movements by 16 h of the prolonged hypoxemia. These studies indicate that the chronically catheterized sheep fetus is able to adapt behaviorally to a prolonged decrease in arterial O2 content secondary to the restriction of uterine blood flow.

Metabolic responses of the whole body, portal-drained viscera and hindquarter to adrenaline infusion: Effects of nonselective and selective β-adrenoceptor blockade

1997 ◽  
Vol 77 (2) ◽  
pp. 307-316 ◽  
Author(s):  
J. O. O. Miaron ◽  
R. J. Christopherson
Keyword(s):  
Blood Flow ◽  
Oxygen Consumption ◽  
Portal Vein ◽  
Influencing Factor ◽  
External Iliac Artery ◽  
Open Circuit ◽  
Whole Body ◽  
Organ Blood Flow ◽  
Β Blocker ◽  
Β Blockers

Propranolol, a nonselective β-blocker and selective β-blockers (metoprolol a β1-blocker and ICI 118551 a β2-blocker) were used to investigate the β-adrenoceptor-mediated adrenaline-induced increase in whole-body and organ VO2 in five whether sheep. Transit time blood flow probes were chronically implanted on the portal vein and the external iliac artery and sampling catheters were placed in the mesenteric artery, iliac vein and portal vein. Oxygen consumption by the whole body was measured by open circuit calorimetry, and oxygen consumption by the portal-drained viscera and the hindquarter was determined from A-VO2 differences and organ blood flow. Absolute pre-infusion VO2 values for the whole body, portal-drained viscera and hindquarters were 236 ± 7.4, 61 ± 6.0 and 13 ± 3.1 mL min−1 respectively. The mean changes in VO2 in response to infusion were 74 vs. 11, 26, 10 and 12 mL min−1 (SE = 9.1) for whole body; 31 vs. −2, −15, 13 and −4 mL min−1 (SE = 7.3) for portal-drained viscera and 8 vs. −0.4, 2.1, 1.0 and −2.7 mL min−1; SE = 4.3) for hindquarters during adrenaline, control, propranolol, metoprolol and ICI 118551 treatments, respectively. Adrenaline increased VO2 (P < 0.05) in the whole body and portal-drained viscera, but not hindquarters relative to controls. All β-blockers suppressed (P < 0.05) the adrenaline-induced increase in VO2 except for the portal-drained viscera where metoprolol was less effective and the hindquarters where β-blockers had no effect. The blood flow pattern was similar to VO2 responses for the portal-drained viscera. The nonselective β1 and β2 blockers were effective in reducing the adrenaline-induced increases in blood flow from the portal-drained viscera and to the hindquarters, with more pronounced β-adrenoceptor-mediated haemodynamic effects. The results indicate that the β-adrenoceptor system modulates whole body VO2, clearly establishes that adrenaline induces an increased VO2 in portal-drained viscera which can be reversed by a β2 or nonselective β blocker and implicates β adrenoceptors as an influencing factor in the maintenance energy requirements of ruminants. Key words: Calorimetry, adrenaline, β blockers, blood flow, sheep

Sign in / Sign up

Export Citation Format

Share Document