Effects of hyperthermia on uterine blood flow and shunting through uterine arteriovenous anastomoses in the late-pregnant ewe

1999 ◽  
Vol 11 (5) ◽  
pp. 201 ◽  
Author(s):  
Suzanne L. Miller ◽  
Graham Jenkin ◽  
David W. Walker

The effect of maternal hyperthermia on uterine blood flow (UBF) through the two main uterine arteries and on the proportion of UBF shunted through uterine arteriovenous anastomoses (AVAs) was investigated. Eight late-pregnant ewes were exposed to normothermic (22–23˚C) or hyperthermic (approx-imately 39˚C) ambient conditions for 8 h. UBF was measured in the left and right uterine arteries using flow probes and microspheres were injected into the uterine artery before, during and after the experimental period. The distribution of microspheres between the uterus and lungs was determined to calculate changes in capillary and AVA blood flows. Hyperthermia produced a significant (P<0.05) increase in maternal core temperature (+1.5˚C), increase in maternal blood pH (+0.21; P<0.05) and decrease in maternal pCO 2 (–16.2 mmHg; P<0.05). Blood flow to the uterine horn ipsilateral to the corpus luteum (CL) remained unchanged during hyperthermia, whereas total UBF and blood flow to the contralateral uterine horn were significantly decreased (P<0.05), by 23.1% and 20.8%, respectively, of pre-heat control values. The proportion of UBF shunted through uterine AVAs during hyperthermia was not significantly different from values observed in normothermic ewes (21.9 0.7%). Mild to moderate hyperthermia in late-pregnant sheep induces respiratory alkalosis and decreases total blood flow to the uterus, brought about by a decrease in blood flow to the uterine horn contralateral, but not ipsilateral to the CL. Heat treatment does not alter the proportion of UBF traversing uterine AVAs.

Gene Therapy ◽  
2011 ◽  
Vol 19 (9) ◽  
pp. 925-935 ◽  
Author(s):  
V Mehta ◽  
K N Abi-Nader ◽  
D M Peebles ◽  
E Benjamin ◽  
V Wigley ◽  
...  

1976 ◽  
Vol 41 (2) ◽  
pp. 197-201 ◽  
Author(s):  
G. K. Oakes ◽  
A. M. Walker ◽  
R. A. Ehrenkranz ◽  
R. C. Cefalo ◽  
R. A. Chez

The effect of induced maternal hyperthermia (1.5 degrees C rise over 60 min) on the uterine and umbilical circulations was examined in two groups of chronically instrumented pregnant sheep. Hyperventilation occurred in both groups. In the group in which the resultant respiratory alkalosis was untreated (N = 5), uterine blood flow decreased to 53 +/- 3% (mean +/- SE; P less than 0.01) of control at maximal maternal temperature. Umbilical blood flow also decreased 30 +/- 6% (P less than 0.01) below control levels. In the other group, normocapnia was maintained (N = 4). Uterine blood flow decreased in this group to 75% +/- 2% (P less than 0.01) of control levels, butumbilical blood flow did not significantly change. There was no significantchange in maternal or fetal mean arterial pressure during hyperthermia ineither group. Thus, maternal hyperthermia per se results in a significant decrease in uterine blood flow primarily through an effect on uterine vascularresistance, but without a concomitant change in umbilical blood flow.


1988 ◽  
Vol 65 (6) ◽  
pp. 2420-2426 ◽  
Author(s):  
A. D. Bocking ◽  
R. Gagnon ◽  
K. M. Milne ◽  
S. E. White

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.


2004 ◽  
pp. 497-502 ◽  
Author(s):  
Danja Str??mper ◽  
Wiebke Gogarten ◽  
Marcel E. Durieux ◽  
Kristian Hartleb ◽  
Hugo Van Aken ◽  
...  

2000 ◽  
Vol 278 (6) ◽  
pp. H2134-H2142 ◽  
Author(s):  
Walid A. Salhab ◽  
Philip W. Shaul ◽  
Blair E. Cox ◽  
Charles R. Rosenfeld

Nitric oxide contributes to estrogen-mediated uterine vasodilation; however, the nitric oxide synthases (NOS) involved and their location within uterine arteries are incompletely documented. We investigated the effects of repetitive daily and acute estradiol-17β (E2β) exposure on uterine hemodynamics and NOS abundance and localization in uterine arteries from nonpregnant ovariectomized ewes receiving daily intravenous E2β (1 μg/kg, n = 5) or no E2β ( n = 7) for 5 days to determine NOS abundance, cGMP contents, and NOS immunohistochemistry. Daily E2β increased basal and E2β-mediated rises in uterine blood flow (UBF) 36 and 43% (<0.01), respectively, calcium-dependent NOS activity 150% ( P < 0.02) in endothelium-intact and -denuded (∼40% of total NOS) arteries, and cGMP contents 39% ( P < 0.05). Endothelial (eNOS) was detected in luminal endothelium, whereas neuronal NOS (nNOS) protein was only in the media. A second group of ewes received E2β (1 μg/kg iv) for 4 days and acute intravenous E2β ( n = 8) or vehicle ( n= 4) on day 5. UBF rose 5.5-fold ( P < 0.001) 115 min after E2β, at which time only endothelium-derived calcium-dependent NOS activity increased 30 ± 13% ( P < 0.05). Daily E2β enhances basal and E2β-mediated increases in UBF, which parallel increases in endothelium-derived eNOS and smooth muscle-derived nNOS. Acute E2β, however, selectively increases endothelium-derived eNOS.


1991 ◽  
Vol 261 (2) ◽  
pp. R508-R514 ◽  
Author(s):  
S. B. Hooper ◽  
A. D. Bocking ◽  
S. White ◽  
J. R. Challis ◽  
V. K. Han

The effects of 24 h of reduced maternal uterine blood flow (RUBF) on relative DNA synthesis rates in different tissues and on blood glucose and lactate concentrations were studied in fetal sheep. In six sheep, RUBF was induced for 24 h, whereas in another six sheep (controls), uterine blood flow was not reduced. To estimate DNA synthesis rate, [3H]thymidine (1 mCi/kg) was injected intravenously into each fetus 8 h before the end of the 24-h experimental period. Fetal arterial oxygen saturation decreased from 59.1 +/- 3.3 to 25.7 +/- 5.6% after 1 h of RUBF and remained significantly reduced for the duration of the experiment. Fetal blood lactate concentrations were significantly increased by RUBF from 14.3 +/- 6.5 to 57.8 +/- 12.4 mg/dl at 1 h and remained elevated, whereas fetal blood glucose concentrations were not affected. A 24-h period of RUBF did not significantly alter fetal body weights, tissue weights, tissue-to-body weight ratios, or tissue DNA content. Over the last 8 h of the 24-h experimental period, RUBF was found to significantly reduce the relative rate of DNA synthesis (as assessed by [3H]thymidine incorporation into DNA) in the lung (104.7 +/- 26.6 vs. 17.1 +/- 3.1 dpm/micrograms DNA), quadriceps muscle (92.8 +/- 20.7 vs. 14.4 +/- 5.3 dpm/micrograms DNA), and thymus gland (87.5 +/- 7.1 vs. 32.9 +/- 12.2 dpm/micrograms DNA). Relative DNA synthesis rates in the fetal liver, kidney, small intestine, cerebral cortex, cerebellum, placenta, thyroid gland, and adrenal gland were not significantly affected by RUBF. In this study, we have shown that DNA synthesis was greatly reduced in selected fetal tissues (lung, quadriceps muscle, and thymus gland) by a 24-h period of RUBF, although it is not known why a reduction was only observed in these tissues.


1998 ◽  
Vol 85 (1) ◽  
pp. 301-309 ◽  
Author(s):  
Martha E. Heath

The purpose of this study was to characterize neuropeptide Y (NPY)-induced vasodilation in the rat tail. Sterile surgical technique was used (with pentobarbital sodium anesthesia) to equip rats with a jugular catheter and a blind-ended thermocouple reentrant tube next to the carotid artery. Tail skin and core temperature were measured with thermocouples during experiments. Tail skin blood flow was monitored with a laser Doppler flowmeter, and tail total blood flow and volume were measured with plethysmography. After baseline data were collected, saline, NPY (16, 32, 64, and 128 μg/kg), [Leu31Pro34]NPY (63.25 μg/kg), or NPY[13–36] (44.7 μg/kg) was administered intravenously. Tail total blood flow, volume, and tail skin temperature increased, whereas tail skin blood flow and core temperature decreased in response to both NPY- and the Y1-receptor agonist [Leu31Pro34]NPY but not in response to saline or NPY[13–36]. Studies conducted with the use of color microspheres demonstrated that arteriovenous anastomoses are involved in this NPY-induced vasodilation.


1993 ◽  
Vol 74 (4) ◽  
pp. 1856-1861 ◽  
Author(s):  
D. R. Corfield ◽  
S. E. Webber ◽  
J. G. Widdicombe

The possible existence of arteriovenous anastomoses (AVAs) in the tracheobronchial circulation has been largely ignored; however, their presence would have many implications. Here we have searched for AVAs in the tracheal circulation of seven anesthetized sheep that were ventilated through a low cervical tracheostomy. Arteries to the midcervical trachea were isolated and perfused in situ at systemic blood pressure; blood flow was measured with an electromagnetic flow probe. A vein draining the perfused segment was cannulated. Radiolabeled microspheres (16 microns diam) injected into the arterial inflow of the perfusion indicated the distribution of blood flow (cervical trachea, 69.9 +/- 4.55% (SE); esophagus, 15.1 +/- 3.9%; connective tissue and blood vessels near trachea, 9.5 +/- 1.8%; lymph nodes, 4.0 +/- 2.2%; skeletal muscle, 0.17 +/- 0.07%; trachea below intubation, 0.00%; larynx, 0.00%; other tissues 0.81 +/- 0.32%). Less than 0.6% of the activity was detected in the tracheal venous blood and lungs, indicating little shunting via AVAs. Within the trachea, blood flow (per wet weight of tissue) to the mucosa overlying smooth muscle was approximately 25% of that to the mucosa overlying cartilage. Intra-arterial infusion of methacholine doubled perfusion blood flow without altering the proportion of shunted blood. Within the trachea, blood flow increased most to the mucosa overlying smooth muscle and to smooth muscle. In conclusion the contribution of AVAs to total blood flow in the cervical trachea is < 1%.


1995 ◽  
Vol 268 (2) ◽  
pp. R303-R309 ◽  
Author(s):  
S. B. Hooper ◽  
D. W. Walker ◽  
R. Harding

Our aim was to compare the effects of short (4 h) and prolonged (24 h) periods of reduced uterine blood flow (RUBF) on fetal and placental uptake of O2, glucose, and lactate. In pregnant sheep, uterine and umbilical blood flows were measured under normal conditions and after 4 and 24 h of RUBF. A 50% reduction in uterine blood flow caused a 56% reduction in fetal arterial O2 saturation (SaO2). Umbilical blood flow increased from 325 +/- 33 to 378 +/- 32 ml.min-1.kg-1 (P < 0.05) after 4 h but was not different from pre-RUBF values after 24 h. O2 uptake by the gravid uterus was not altered by RUBF, due to an increase (84%) in uterine O2 extraction. Similarly, uteroplacental and fetal O2 consumptions and fetal glucose uptake were not affected by RUBF, whereas uteroplacental glucose uptake was significantly reduced after 4 h (by 42%) and 24 h (by 58%) of RUBF. Fetal lactate uptake was greatly reduced from 78.7 +/- 15.5 to -167 +/- 57 mumol.min-1.kg-1 after 4 h and to -198 +/- 80 mumol.min-1.kg-1 after 24 h of RUBF; negative values indicate placental lactate uptake from the fetal circulation. Thus, although RUBF significantly reduced fetal SaO2, fetal and uteroplacental O2 consumptions did not change. In addition, although fetal glucose uptake was not altered by RUBF, during RUBF the placenta became a major site of lactate clearance from the fetal circulation.


2016 ◽  
Vol 7 (3) ◽  
pp. 92-97 ◽  
Author(s):  
Arutyun F Arutyunyan ◽  
Sergey N Gaydukov ◽  
Vitaly N Kustarov

The purpose of our study was to assess the effectiveness of the use of drugs containing indole-3-carbinol and epigallocatechin-3 gallate in combination with effective natural methods (TES-therapy and hirudotherapy) depending on the degree of morphological adenomyosis. The study involved 205 women with diffuse adenomyosis. Based on survey data from 205 women surveyed in 67 verified adenomyosis first degree (Group 1), 79 - second degree adenomyosis (group 2), and 59 - third degree adenomyosis (group 3). Doppler results showed that in patients with adenomyosis first degree nizkorezistentny uterine blood flow was observed. Improvement of clinical symptoms of the disease, increasing the numerical values of R & D in the uterine arteries at the first degree adenomyosis indicates pathogenic effects of the proposed treatment. At the same time in patients with adenomyosis II-III degree was observed with highly bloodstream, indicating the deterioration of blood flow in the uterine vascular basin, as evidenced by some of hemostasis. Thus, studies have provided credible evidence pathogenesis mediated relations between the characteristics of the circulation of the uterus, the processes of neoangiogenesis, proliferation in the myometrium and the extent of spread of the disease, which will choose the appropriate methods of conservative treatment. Using drugs and Indinol epigallat affecting the basic pathogenetic mechanisms of adenomyosis, opens a new direction in the treatment of this disease, and effective natural methods - new opportunities in the treatment of adenomyosis.


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