Dynamics of Follicular Blood Flow, Antrum Growth, and Angiogenic Mediators in Mares From Deviation to Ovulation

doi:10.1016/j.jevs.2017.04.003

Journal of Equine Veterinary Science

Volume 55, August 2017, Pages 51-59

https://doi.org/10.1016/j.jevs.2017.04.003 Get rights and content

Highlights

•
Blood flow toward preovulatory follicle increased from day −6 till day of ovulation.
•
Blood flow plays a role in maturation of the dominant follicle.
•
Nitric oxide and angiogenic hormones play a role in ovulation of the dominant follicle in mares.

Abstract

This study aimed to investigate dynamics of dominant and subordinate follicles' change of dimensions, vascularity, and angiogenic hormones from deviation to ovulation. Ten cyclic mares were subjected to daily blood sampling and Doppler examination along two estrous cycles. Three diameters were recorded for each follicle to estimate its area and volume. Leptin, insulin-like growth factor-I (IGF-1), nitric oxide (NO) and estradiol were measured. Area of color and power Doppler modes with antral area and circumference of all follicles was measured in pixels. Follicles were classified into first large preovulatory follicle (1st F-ov), second large (2nd F-ov), and third large (3rd F-ov) on the ovulating ovary and on the contralateral nonovulating ovary into first (1st F-contra) and second large (2nd F-contra). Days before ovulation significantly (P < .0001) affected all dimensions of preovulatory follicle. With the increase of diameter, area, volume, area in pixel, antrum area, and circumference of 1st F-ov, those of all subordinates were decreasing. The blue flow area, power, and power minus red blood flow area of 1st F-ov increased from day −6 till day of ovulation (day 0), but red blood flow area significantly decreased. First large follicle had the lowest percent of colored pixels and percent of the colored pixels without antrum. Estradiol and leptin increased from day −6 till day 0, but IGF-1 decreased till day −1 and NO achieved a peak on day −3 then decreased till day 0. In conclusion, antrum growth, blood flow, and angiogenic hormones play a role in maturation and ovulation of the dominant follicle in mares.

Introduction

Follicular blood flow was previously studied using histological techniques http://www.sciencedirect.com/science/article/pii/S0301211511001837 [1], thermo-couple methods [2], isotope techniques [3], and pulsed Doppler ultrasonography [4]. The level of follicular vascularity directly affects the nutrient supply to the follicle and has been linked to in vitro fertilization (IVF) outcomes [5]. The nutrient composition of intrafollicular fluid has become a prognostic parameter for selecting oocytes for IVF [6]. Color-flow Doppler ultrasound has been investigated for predicting follicle fertility [7] and ovulation [8] and to elucidate relationships among oocyte recovery, oocyte maturation, and blood flow to equine follicles [9]. In mares, color Doppler ultrasonography helped to determine if a follicle is going to be anovulatory hemorrhagic follicle [10]. Diminishing follicle turgidity, loss of spherical shape, overabundance echoic spots in the antrum, serration of the granulosa, and presence of an apical range were the criteria to distinguish between ovulatory and anovulatory follicles [10].

During follicle development, a broad vascular plexus forms in the thecal layer surrounding the avascular basement membrane and granulosa layer [11]. A vascular framework in individual follicles assumes a part of determination and development of the dominant follicle [12] and that insufficient vascular support contributes to follicle atresia [12], [13]. The preovulatory follicle consists of a fluid-filled antrum encapsulated progressively (from inside to outside) by granulosa, theca interna, and theca externa layers [14]. The avascular stratum granulosum is separated from the vascular thecal layers by a basal membrane. The theca interna is a layer of glandular cells mingled with a rich capillary plexus. The theca externa is more fibrous but contains a prominent network of arterioles and venules. As the follicle matures, expansion of the theca vessels and capillaries involves formation of new vessels as well as dilation of existing vessels [15], [16].

The purpose of this study was to investigate the dynamics of the growth of preovulatory follicle, antrum, vascularization, and systemic angiogenic mediators in comparison to the subordinates after completing deviation till ovulation.

Section snippets

Animals and Ultrasound Scanning

Ten nonlactating brood mares (5–9 years old) of European × Egyptian crossbred horses of moderate body condition score (BCS = 5), according to the scale from 1 to 9 [17], were subjected to Doppler ultrasonographic examination daily for 18-day throughout two estrous cycles. Mares were given 1 week off rectal examinations between the two estrous cycles. Mares were granted from Training Department (El-Basaten Horsley, Ministry of interior) and kept in an indoor paddock with partition individually

Results

Generally, days before ovulation significantly affected color blood flow away transducer (P < .016), power blood flow area (P < .016), and colored pixel % (P = .0001) but tended (P = .06) to influence the diameter of all follicles from day −6 till day 0. Concentrations of E₂, leptin, IGF-1, and NO are significantly influenced by days before ovulation (P < .0001). During the significant (P = .0001) daily increase of diameter, area, volume measured by electronic calipers and antrum area, area and

Diameter and Antral Area

In mares, the mean size of the preovulatory follicle prior to ovulation has been reported to be 40 mm, with a very large range from 30 to 70 mm [22], [23]. Regardless individual variations, mares of the current study had lower mean preovulatory follicle growth rate (2.2 mm in day) compared to previously reported (3 mm in day) until 1 day preovulation [24]. During this study, the increase of mean diameter of preovulatory follicle from 2.90 ± 0.07 cm on day −6 to 3.96 ± 0.07 cm on day of

Acknowledgments

The authors wish to thank the staff officer doctors of ElBasatten Horsley for granting horses to perform this study and National Research Center for availability of the Doppler Scanner.

References (56)

O.J. Ginther et al.
Incidence, endocrinology, vascularity, and morphology of hemorrhagic anovulatory follicles in mares
J Equine Vet Sci
(2007)
T.M. Hazzard et al.
Angiogenesis in ovarian follicular and luteal development
Baillieres Best Pract Res Clin Obstet Gynaecol
(2000)
R.J. Rodgers et al.
Irving-Rodgers HF,.Development of the ovarian follicular epithelium Molecular
Endocrinol
(1999)
H. Bollwein et al.
Luteal blood flow during the estrous cycle in mares
Theriogenology
(2002)
E.A. Abdelnaby et al.
Assessment of uterine vascular perfusion during the estrous cycle of mares in connection to circulating leptin, and nitric oxide concentrations
J Equine Vet Sci
(2016)
D.R. Bergfelt et al.
Relationships between FSH surges and follicular waves during the estrous cycle in mares
Therio
(1993)
C. Aurich
Reproductive cycles of horses
Anim Reprod Sci
(2011)
M.A. Dimmick et al.
Ovarian follicular dynamics and duration of estrus and diestrus in Arabian vs. Quarter Horse mares
Anim Reprod Sci
(1993)
O.J. Ginther et al.
Age-related dynamics of follicles and hormones during an induced ovulatory follicular wave in mares
Theriogenology
(2009)
E.L. Gastal et al.
Temporal relationships among LH, estradiol, and follicle vascularization preceding the first compared with later ovulations during the year in mares
Anim Reprod Sci
(2007)

R.A. Pierson et al.

Ultrasonic evaluation of the preovulatory follicle in the mare

Theriogenology

(1985)

M. Rossi et al.

The investigation of skin blood flow motion: a new approach to study the microcirculatory impairment in vascular diseases

Biomed Pharma Cother

(2006)

S. Bertuglia et al.

Effects of L-NMMA and indomethacin on arteriolar vasomotion in skeletal muscle microcirculation of conscious and anaesthetized hamsters

Microvasc Res

(1994)

H. Balakier et al.

Colour Doppler assessment of percentage circumference demonstrating visible flow. We have folliculogenesis in in vitro fertilization patients

Fertil Steril

(1994)

M.O. Gastal et al.

Short-term feed restriction decreases the systemic and intrafollicular concentrations of leptin and increases the vascularity of the preovulatory follicle in mares

Theriogenology

(2010)

O.J. Ginther et al.

Blood flow to follicles and CL during development of the periovulatory follicular wave in heifers

Theriogenology

(2014)

M.A. Siddiqui et al.

Blood flow in the wall of the preovulatory follicle and its relationship to pregnancy establishment in heifers

Anim Reprod Sci

(2009)

M.C. Witt et al.

Doppler sonography of the uterine and ovarian arteries during a superovulatory program in horses

Theriogenology

(2012)

D. Kelley et al.

Influence of L-arginine supplementation on reproductive blood flow and embryo recovery rates in mares

Theriogenology

(2014)

M. Baltsen et al.

Content of meiosis activating sterols in equine follicular fluids: correlation to follicular size and dominance

Theriogenology

(2001)

N. Gérard et al.

Relationships between follicular fluid composition and follicular in oocyte quality in the mare

Livestock Produc Sci

(1999)

J.L. Cavender et al.

Morphological studies of the microcirculatory system of periovulatory ovine follicles

Biol Reprod

(1998)

S. Makinoda et al.

Hemodynamic histologic studies of ovarian blood flow during the preovulatory period

P.O. Janson

Effects of the luteinizing hormone on blood flow in the follicular rabbit ovary, as measured by radioactive microspheres

Acta Endocrinol

(1957)

T.J. Acosta et al.

Local changes in blood flow within the preovulatory follicle wall and early corpus luteum in the cow

Reproduction

(2003)

A.R. Clark et al.

Follicle structure influences the availability of oxygen to the oocyte in antral follicles

Comput Math Methods Med

(2011)

C.Y. Andersen

Characteristics of human follicular fluid associated with successful conception after in vitro fertilization

J Clin Endocrinol Metab

(1993)

L.A. Silva et al.

Relationships between vascularity of the preovulatory follicle and establishment of pregnancy in mares

Anim Reprod

(2006)

Cited by (25)

Effect of pyometra on vascularity alterations, oxidative stress, histopathology and inflammatory molecules in feline
2024, Reproductive Biology
This study aimed to investigate blood flow, hemodynamical features by Doppler ultrasound, the oxidative stress biomarkers from serum samples, and histopathology from uterine tissue, in healthy queens and queens with pyometra. Twenty queens were categorized into two groups, according to signs, history, and ultrasound findings, as pyometra and control healthy queens. Doppler ultrasonography, total antioxidant capacity (TAC), malondialdehyde (MDA), albumin, bacteriological isolation, histopathology, and immunohistochemistry of tumor necrosis factor-alpha (TNF-α) and nuclear factor kappa B (NF-κB) P65 were performed. Uterine diameter and thickness increased significantly in the pyometra group compared to control. Uterine peak velocity and flow rate were significantly higher in the control group. The pyometra group showed a significant decrease in albumin, TAC, and a significant increase in MDA. Fibrosis and mononuclear inflammatory cell infiltration were seen in the pyometra samples. The mean area percentage of TNF-α expression in the uteri of the pyometra group was higher. The expression of NF-κB P65 in the uteri in the pyometra group was significantly higher. Doppler ultrasonography can provide valuable information for diagnosing pyometra in queens by elevating the uterine thickness with reducing blood flow rate. Oxidative stress, TNF-α, and NF-κB expression alterations varied between pyometra and control groups.
Evaluation of ovarian hemodynamics by color and spectral Doppler in cows stimulated with three sources of follicle-stimulating hormone
2021, Reproductive Biology
This study hypothesized that ovarian response for superovulation is better when using compounds containing luteinizing hormone (LH). To compare the ovarian responses and the ovarian blood flow using three gonadotropins, three equal groups of Holstein cows (N = 18) were treated with Pluset (P), Follitropin (F), and eCG (G). The ovarian response was evaluated from the day of starting treatments (Day -5) till Day 5 after ovulation using Doppler ultrasound. Results revealed that the ovarian arteries pulsatility index (PI), peak systolic velocity (PSV), and the blood flow volume (BFV) varied (P < 0.0001) between both ovarian arteries. Cows treated with P had low number of small and medium follicles and a high number of the large follicles on Day -1. Cows treated with F showed low (P = 0.0001) number and percentage of colored follicles and high % of ovulated follicles (P=0.0001) that obtained high colored areas (P = 0.043) and colored area % (P = 0.001). The G produced more (P = 0.001) colored follicles (Days -1, 0) of low area. Both P and G had the same higher (P = 0.0001) percentages of colored follicles (>80 %) on Day-1 than F (<60 %). F and P had higher ovulated colored follicles % than G. P obtained nearly the same ovulated follicles diameters and areas as F with higher antrum area (P = 0.029) but lower colored area (P = 0.043) and colored area % (P = 0.001). In conclusion, the number and the doses of gonadotropin injections and the side of the ovary influenced the ovarian response.
Hemodynamic changes evaluated by Doppler ultrasonographic technology in the ovaries and uterus of dairy cattle after the puerperium
2020, Reproductive Biology
Citation Excerpt :
While some studies have demonstrated the importance of quick returning of ovarian activity and animal cyclity sometime related to fertility [7,10], others have recently focused on the high occurrence of anestrus in high-producing animals [11,12]. Applicability of ultrasound especially Doppler technology is a useful technique for the evaluation of the genital blood flow [13–15]. Doppler evaluation of ovarian and uterine vascularization has been mostly used to detect and determine women uterine involution after giving a baby.
The present detailed study aimed to establish for the first time the ovarian and uterine hemodynamic change in dairy cows after the end of the puerperal period to investigate a possible association between Doppler indices and volume of blood flow. Twenty cows weighing 500–600 kg (mean 400 ± 50 kg) and 4–5 years of age (mean 3.2 ± 0.5 years) categorized into two main groups (true anestrum, with corpus luteum, n = 10) and (normal cyclic, n = 10), The period of examination started from day 39 till day 70 after calving with day after day routinely examination by b-mode and Doppler performed on both ovaries with ovarian arteries (OA) and uterus with uterine arteries (MUA) in the ipsilateral (ipsi) and contralateral (contra) side to ovulation, in addition to a thickness in horns and body was measured. Estradiol and progesterone were also measured. Results showed that both Doppler indices in the OA and MUA ipsi and contra had a positive (P ≤ 0.001) correlation with contra Doppler indices, but revealed a negative (P ≤ 0.05) correlation with ipsi and contra Doppler velocities, blood flow rate and volume in anestrum cows. Both ovarian and uterine ipsi indices showed an increase (P ≤ 0.05) in the anestrum cows, and both PSV and EDV of both arteries ipsilateral showed (P ≤ 0.05) a decrease in the anestrum cows, the ipsi and contra ovarian and uterine colored % were lower in anestrum group than the normal group. Estradiol (P ≤ 0.05) decreased in anestrum cows than the normal, while progesterone increased in the anestrum group. Conclusion, although uterine and ovarian morphology were changed in anestrum cows, the vascular system of the ovary as well as uterus underwent much more marked vascular changes, the most significant being that of blood flow velocities and volume.
Gross Anatomical, Radiographic and Doppler Sonographic Approach to the Infra-auricular Parotid Region in Donkey (Equus asinus)
2020, Journal of Equine Veterinary Science
The present study was performed on 12 heads of donkey’s cadavers of both sexes for different anatomic techniques and on 20 live adult donkeys for ultrasonographic approaches of local anesthetic techniques. The aim was to achieve safe desensitization of the ear canal and tympanic membrane in addition to measuring different parameters of the structures occupying the infra-auricular parotid region. The internal auricular nerve was divided into two fine branches and constituting, at its origin, a characteristic V-shape with the caudal auricular nerve. The styloid process of auricular cartilage was an adequate landmark for ultrasonographic needle-guided anesthesia for internal auricular and auriculopalpebral nerves, whereas the great auricular nerve was easily palpated subcutaneously that showed safety and success in all cases. The auricular branch of mandibular nerve joined the auriculopalpebral branch of facial nerve. The maxillary vein was descending, partially embedded within the texture of the parotid glandular tissue. The parotid gland divided into five segments was clearly demarcated by maxillary vein tributaries with three main collecting radicles pouring into the parotid duct. The mandibular duct received about 12–15 fine radicles and supplied with a separate branch from the external carotid artery. Using the Doppler sonographic technique in donkeys for diagnosis of ear affections, evaluation of retrograde sialography to salivary glands with their blood vasculature and their indices might be helpful for the detection of different critical abnormalities, such as stenosis, thrombosis, and other vasopathological affections through measuring their resistivity and pulsatility indices.
Associations among thermal biology, preovulatory follicle diameter, follicular and luteal vascularities, and sex steroid hormone concentrations during preovulatory and postovulatory periods in tropical beef cows
2020, Animal Reproduction Science
Citation Excerpt :
To visualize the ovarian POF and CL structures, transrectal color Doppler ultrasonography was performed using a 5.0 MHz linear-array transducer for B mode (gray scale) and color imaging software (SonoTouch 30VET; Chison Medical Imaging Co., Ltd., China). The amount of ovarian POF and CL tissue in which there was vascularization was designated as vascularization areas, and were quantified from the Doppler color images using the procedures described for mares (Abdelnaby et al., 2016; Abdelnaby and Abo El-Maaty, 2017a, 2017b) and dairy cows (Varughese et al., 2017). Briefly, Doppler color images per pixel density were created using Adobe Photoshop CC software (1990–2017, Adobe system).
The objectives were to evaluate effects of tropical seasons on thermal biology, preovulatory follicle (POF) diameter, POF and luteal vascularities, and estradiol (E2) and progesterone (P4) concentrations; and to determine the associations among the values for these variables during preovulatory and postovulatory periods in Thai native cows in tropical climates: cold, hot, and rainy seasons. Development and vascularity of the POF and corpora lutea (CL) were evaluated using color Doppler ultrasonography. The temperature-humidity index (THI) was greater when the preovulatory period occurred during the rainy season when compared with the occurrence during the hot and cold seasons of the year. Furthermore, POF diameter was less when the THI was greater. The THI was greater when the postovulatory period occurred during the rainy season when compared to the occurrence of the postovulatory period during the hot and cold seasons of the year. Furthermore, the CL vascularity and P4 concentration were less when the THI was greater. The THI was inversely correlated with CL vascularity and P4 concentrations. When the THI was greatest during the hot and rainy seasons of the year, there were the greatest negative effects on POF size, POF and CL blood flow, and concentrations of E2 and P4 during the preovulatory and postovulatory periods. While native Bos indicus are capable of adapting to tropical conditions, there are still negative effects, such as impaired POF and CL functions, when the THI induces heat stress.
Dynamics of uterine and ovarian arteries flow velocity waveforms and their relation to follicular and luteal growth and blood flow vascularization during the estrous cycle in Friesian cows
2018, Theriogenology
Citation Excerpt :
The same analyzer traced all follicles on both ovaries with tracing the small follicle that destined to be either large ovulating or non-ovulating. When a corpus luteum developed at the site of a large dominant preovulatory follicle (>13 mm), it determined ovulation (Day 0) [18]. The follicular phase included days from Day −5 to 0, and the luteal phase included days from Day 1–15 which equally subdivided into the early luteal (growth phase) which included Days from 1 to 5; mid-luteal (Static phase) which included Days from 6 to 10; and late luteal (Regression phase) which included Days from 11 to 15.
Doppler ultrasonography enabled understanding of the reproductive system hemodynamics in cyclic and pregnant cattle. To confirm the hypothesis that the ipsilateral ovarian and uterine arterial blood flows to the ovulating ovary are higher than the contralateral one along days and phases (follicular, early luteal, mid-luteal, late luteal) of the estrous cycle, eight cyclic spontaneously ovulating cows were scanned with Doppler ultrasound each other day along three oestrous cycles to monitor the follicular dynamics, the vascularization of the ovulatory follicle (OF), the corpus luteum (CL) developmental dynamics, the ipsilateral and the contralateral ovarian and uterine arterial diameters and their blood flow. Results proved the hypothesis. Both days and phases of the estrus cycle influenced (P = 0.0001) the follicular dynamic, the luteal hemodynamics, the ovarian and uterine hemodynamic. The ovulatory wave and the mid-luteal non-ovulatory wave had expanding numbers and the diameters of small, medium and large follicles. Though area, antral area, vascularization area of the OF ascended from Day −4 to the day of ovulation (Day 0), but the percent of its vascularization area and that of granulose layer increased till Day −3. The CL diameter increase till Day 15, and its vascularization area increased till Day 13, but its% of vascularization area ascended (P = 0.0001) from Days 1–4 and declined from Days 9–13. Both RI and PI of the ipsilateral ovarian artery were lower than the contralateral one; but, both obtained high values during the follicular phase. A linear increase (P = 0.0001) of uterine horns vascularization area and both ovarian and uterine arteries diameters, PSV and EDV from follicular to late luteal phases accompanied a linear decrease of their PI and RI. In conclusion, the ovarian and uterine blood flows vary according to the estrous day, estrous phase, the ovulating ovary, ovulatory follicle growth and corpus luteum developmental stage.

View all citing articles on Scopus

: Conflict of interest: The authors declare that they do not have any conflict of interest.

View full text

Review ArticleDynamics of Follicular Blood Flow, Antrum Growth, and Angiogenic Mediators in Mares From Deviation to Ovulation

Highlights

Abstract

Introduction

Section snippets

Animals and Ultrasound Scanning

Results

Diameter and Antral Area

Acknowledgments

J Equine Vet Sci

Baillieres Best Pract Res Clin Obstet Gynaecol

Endocrinol

Theriogenology

J Equine Vet Sci

Therio

Anim Reprod Sci

Anim Reprod Sci

Theriogenology

Anim Reprod Sci

Theriogenology

Biomed Pharma Cother

Microvasc Res

Fertil Steril

Theriogenology

Theriogenology

Anim Reprod Sci

Theriogenology

Theriogenology

Theriogenology

Livestock Produc Sci

Morphological studies of the microcirculatory system of periovulatory ovine follicles

Biol Reprod

Hemodynamic histologic studies of ovarian blood flow during the preovulatory period

Effects of the luteinizing hormone on blood flow in the follicular rabbit ovary, as measured by radioactive microspheres

Acta Endocrinol

Local changes in blood flow within the preovulatory follicle wall and early corpus luteum in the cow

Reproduction

Follicle structure influences the availability of oxygen to the oocyte in antral follicles

Comput Math Methods Med

Characteristics of human follicular fluid associated with successful conception after in vitro fertilization

J Clin Endocrinol Metab

Relationships between vascularity of the preovulatory follicle and establishment of pregnancy in mares

Anim Reprod

Review Article
Dynamics of Follicular Blood Flow, Antrum Growth, and Angiogenic Mediators in Mares From Deviation to Ovulation