Real-time characterization of the uterine blood flow in mares before and after artificial insemination

The objectives were to investigate the ovarian dynamics and hormonal profiles during the oestrus cycle, and to characterize the ovarian and uterine blood flow (OBF versus UBF) indices on the extent of vascular perfusion towards the dominant follicle (DF) or corpus luteum (CL) during the peri-ovulatory follicular wave in Sahiwal cows. In experiment 1, cyclic cows (n = 21) were selected at their spontaneous oestrus (day 0) and subjected to B-mode ultrasonography throughout the oestrus cycle. In experiment 2, cyclic cows (n = 9) were randomly selected at day 0, and categorized according to the intra-ovarian patterns as ovaries with DF (n = 3), CL (n = 3) or both (DF+CL; n = 3) to characterize the OBF and UBF indices using Doppler ultrasonography. The length of the oestrus cycle (days), number of follicular waves (n) and size (mm) of DF and CL were 20.1 ± 0.9, 2.1 ± 0.2, 14.7 ± 0.7 and 15.9 ± 2.5, respectively. The concentrations (ng/mL) of plasma progesterone increased linearly, and a peak was attained at day 12.2 ± 1.0. However, it reduced linearly with the onset of luteolysis at day 16.4 ± 0.3 of the oestrus cycle. The plasma progesterone (P4) concentrations and the diameter of CL correlated throughout the oestrus cycle. The mean OBF and UBF indices did not differ between intraovarian patterns. Taken together, this information on reproductive physiological parameters could be used to develop synchronization protocols to improve reproductive management in Sahiwal cows.

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Effect of exercise on cardiac output and distribution of uterine blood flow in pregnant ewes

Journal of Applied Physiology ◽

10.1152/jappl.1976.40.5.725 ◽

1976 ◽

Vol 40 (5) ◽

pp. 725-728 ◽

Cited By ~ 28

Author(s):

L. B. Curet ◽

J. A. Orr ◽

H. G. Rankin ◽

T. Ungerer

Keyword(s):

Heart Rate ◽

Blood Flow ◽

Stroke Volume ◽

Physical Training ◽

Exercise Stress ◽

Compensatory Mechanism ◽

Uterine Blood Flow ◽

Flow Measurements ◽

Before And After ◽

Blood Flow Measurements

This study was designed to determine what effect physical training has on heart rate and stroke volume responses to exercise stress and to determine if exercise altered the distribution of uterine blood flow. Measurements were made in ten pregnant ewes at rest and immediately following exercise on a treadmill. Five ewes underwent physical training for 3 wk prior to measurement. An increase in heart rate with no change in stroke volume was observed following exercise in both trained and untrained ewes. Total uterine blood flow was not changed following exercise, but distribution was altered in favor of the placenta. Blood flow was evenly distributed within the placenta before and after exercise. The redistribution of flow to the placenta that occurs after exercise. tphe redistribution of flow to the placenta that occurs after exercise might represent a compensatory mechanism for the fetus.

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Treated and untreated anovulation associated with ovarian and uterine blood flow in Arabian mares (a case study)

Roczniki Naukowe Polskiego Towarzystwa Zootechnicznego ◽

10.5604/01.3001.0013.5083 ◽

2018 ◽

Vol 14 (3) ◽

pp. 21-34

Author(s):

Amal M. Abo El-Maaty ◽

Yehia El Baghdady ◽

Khalid A. ElShahat ◽

Mahmoud A. Helmy ◽

Elshymaa A. Abdelnaby

Keyword(s):

Blood Flow ◽

Power Doppler ◽

Serum Levels ◽

Uterine Horn ◽

Uterine Blood Flow ◽

Before And After ◽

Antral Area ◽

Uterine Body ◽

Area And Volume

To investigate the development of treated and untreated hormonal anovulatory follicles (AnOV) associated with uterine and ovarian vascularization, rectal Doppler ultrasound of seven Arabian mares was performed before and after the development of an AnOV. In addition to measuring the diameter, area and volume of the follicle, daily colour and power Doppler scans were analysed in order to measure red, blue and power blood flow areas in pixels. Serum levels of estradiol (E2), progesterone (P4), leptin, insulin-like growth factor-I (IGF-1) and nitric oxide (NO) were measured as well. The diameter (cm), area (cm2), volume (cm3), area in pixels, antral area in pixels, circumference, and percentage change in circulation of the AnOV progressively increased (P<0.0001) after the disappearance of uterine oedema compared to the values obtained during oedema. The blue, total colour and power areas of the AnOV increased after the disappearance of uterine oedema (P<0.0001). When the antral area was excluded, the percentage of the granulosa layer in the colour and power Doppler decreased after the disappearance of uterine oedema. The ipsilateral uterine horn and uterine body had significantly (P<0.0001) high blue and red blood flow vascularization areas in the presence of uterine oedema. The AnOV was associated with low P4, IGF-1 (P<0.001), and leptin (P<0.05). Treatment of the AnOV follicle with GnRH resulted in its luteinization and induced ovulation 9 and 30 days later. It can be concluded that an abrupt increase in blood flow due to decreased progesterone and E2 and increased IGF-1 causes anovulation. The absence of oestrous behaviour and high uterine-oedema-associated follicular and ipsilateral uterine horn vascularization are predictors of ovulation failure.

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Characterization of Blood Flow in the Mouse Dorsal Spinal Venous System before and after Dorsal Spinal Vein Occlusion

Journal of Cerebral Blood Flow & Metabolism ◽

10.1038/jcbfm.2014.244 ◽

2015 ◽

Vol 35 (4) ◽

pp. 667-675 ◽

Cited By ~ 6

Author(s):

Matthew J Farrar ◽

Jonathan D Rubin ◽

Darcy M Diago ◽

Chris B Schaffer

Keyword(s):

Blood Flow ◽

Ex Vivo ◽

Laboratory Mouse ◽

Microvascular Network ◽

Vein Occlusion ◽

Before And After ◽

Diseased State ◽

Dorsal Spinal

The availability of transgenic strains has made the laboratory mouse a popular model for the study of healthy and diseased state spinal cord (SC). Essential to identifying physiologic and pathologic events is an understanding of the microvascular network and flow patterns of the SC. Using 2-photon excited fluorescence (2PEF) microscopy we performed in vivo measurements of blood flow in the lower thoracic portion of the mouse dorsal spinal vein (dSV) and in the first upstream branches supplying it, denoted as dorsal ascending venules (dAVs). We found that the dSV had large radiculomedullary veins (RMVs) exiting the SC, and that flow in the dSV between pairs of RMVs was bidirectional. Volumetric flow increased in each direction away from the point of bifurcation. Flow in the upstream dAVs varied with diameter in a manner consistent with a constant distal pressure source. By performing ex vivo 2PEF microscopy of fluorescent-gel perfused tissue, we created a 3-D map of the dorsal spinal vasculature. From these data, we constructed a simple model that predicted changes in the flow of upstream branches after occlusion of the dSV in different locations. Using an atraumatic model of dSV occlusion, we confirmed the predictions of this model in vivo.

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BP Fluctuations and the Real-Time Dynamics of Renal Blood Flow Responses in Conscious Rats

Journal of the American Society of Nephrology ◽

10.1681/asn.2019070718 ◽

2019 ◽

Vol 31 (2) ◽

pp. 324-336 ◽

Cited By ~ 4

Author(s):

Anil K. Bidani ◽

Aaron J. Polichnowski ◽

Hector Licea-Vargas ◽

Jianrui Long ◽

Stephanie Kliethermes ◽

...

Keyword(s):

Blood Flow ◽

Renal Blood Flow ◽

Real Time ◽

Time Dynamics ◽

Renal Autoregulation ◽

Conscious Rats ◽

Before And After ◽

Stable Renal Function ◽

Conscious Animals ◽

Glomerular Capillaries

BackgroundRenal autoregulation maintains stable renal function despite BP fluctuations and protects glomerular capillaries from hypertensive injury. However, real-time dynamics of renal autoregulation in conscious animals have not been characterized.MethodsTo develop novel analytic methods for assessing renal autoregulation, we recorded concurrent BP and renal blood flow in conscious rats, comparing animals with renal autoregulation that was intact versus impaired (from 3/4 nephrectomy), before and after additional impairment (from the calcium channel blocker amlodipine). We calculated autoregulatory indices for adjacent short segments of increasing length (0.5, 1, 2.5, 5, 10, and 20 seconds) that exhibited a mean BP difference of at least 5 mm Hg.ResultsAutoregulatory restoration of renal blood flow to baseline after BP changes in conscious rats occurs rapidly, in 5–10 seconds. The response is significantly slower in states of impaired renal autoregulation, enhancing glomerular pressure exposure. However, in rats with severe renal autoregulation impairment (3/4 nephrectomy plus amlodipine), renal blood flow in conscious animals (but not anesthetized animals) was still restored to baseline, but took longer (15–20 seconds). Consequently, the ability to maintain overall renal blood flow stability is not compromised in conscious rats with impaired renal autoregulation.ConclusionsThese novel findings show the feasibility of renal autoregulation assessment in conscious animals with spontaneous BP fluctuations and indicate that transient increases in glomerular pressure may play a greater role in the pathogenesis of hypertensive glomerulosclerosis than previously thought. These data also show that unidentified mechanosensitive mechanisms independent of known renal autoregulation mechanisms and voltage-gated calcium channels can maintain overall renal blood flow and GFR stability despite severely impaired renal autoregulation.

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An Electron Microscope Study of Interdiffusion and Compound Formation in Ta-Au Thin Films

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100070606 ◽

1973 ◽

Vol 31 ◽

pp. 32-33 ◽

Cited By ~ 1

Author(s):

T. C. Tisone ◽

S. Lau

Keyword(s):

Electron Microscope ◽

Electron Microscope Study ◽

Thermally Grown Oxide ◽

Ion Milling ◽

Compound Formation ◽

Technology Application ◽

Transmission Electron ◽

Before And After ◽

Au Thin Films

In a study of the properties of a Ta-Au metallization system for thin film technology application, the interdiffusion between Ta(bcc)-Au, βTa-Au and Ta2M-Au films was studied. Considered here is a discussion of the use of the transmission electron microscope(TEM) in the identification of phases formed and characterization of the film microstructures before and after annealing.The films were deposited by sputtering onto silicon wafers with 5000 Å of thermally grown oxide. The film thicknesses were 2000 Å of Ta and 2000 Å of Au. Samples for TEM observation were prepared by ultrasonically cutting 3mm disks from the wafers. The disks were first chemically etched from the silicon side using a HNO3 :HF(19:5) solution followed by ion milling to perforation of the Au side.

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