DOCSLIB.ORG

Effects of Section of Utero-Ovarian Vascular Connections on the Duration of Pseudopregnancy in the Rat

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Effects of Section of Utero-Ovarian Vascular Connections on the Duration of Pseudopregnancy in the Rat EFFECTS OF SECTION OF UTERO-OVARIAN VASCULAR CONNECTIONS ON THE DURATION OF PSEUDOPREGNANCY IN THE RAT J. D. O'SHEA and C. S. LEE Department of Veterinary Preclinical Sciences, University of Melbourne, Parkville, Victoria 3052, Australia (Received 20th March 1972) Summary. Two experiments were performed on female Hooded Wistar rats to determine the effects ofsection of utero-ovarian connections on the duration of pseudopregnancy. Ligation and section of the anterior uterine blood vessels on Day 6 of pseudopregnancy caused a prolongation of the pseudopregnancy during which the operation was performed, and also of the subsequent pseudopregnancy (P<0\m=.\01).Neither section of the Fallopian tube nor that of the mesosalpinx and broad ligament significantly affected the duration of pseudopregnancy. When the anterior uterine vessels were sectioned separately, it was shown that severing the artery led to a prolongation of pseudopregnancy (P<0\m=.\001).Section of the vein did not significantly affect the duration of pseudopregnancy. These results suggest that the effects on pseudopregnancy of section of utero-ovarian connections depend primarily on interruption of the anterior uterine artery. INTRODUCTION There is considerable evidence that in many species of mammals the life-span of the corpus luteum is controlled, at least in part, by the release of a luteolytic substance or substances from the uterus (Schomberg, 1969; Rowson, 1970). The concept that uterine luteolytic activity involves a local, unilateral com¬ ponent, whereby each uterine horn is able to exert a preferential effect on the ipsilateral ovary, has also been supported by data from several species (Fischer, 1967; Ginther, 1967). Evidence of local uterine luteolytic activity in the rat derives principally from the demonstration by Barley, Butcher & Inskeep (1966) that unilateral hysterectomy accompanied by contralateral ovariectomy leads to a prolonga¬ tion of pseudopregnancy, whereas unilateral hysterectomy with ipsilateral ovariectomy is without effect. Ligation and cutting of the oviduct and meso¬ salpinx also led to a prolongation of pseudopregnancy, and Barley et al. (1966) concluded that the ability of the uterus to limit the life-span of the corpora lutea 245 Downloaded from Bioscientifica.com at 09/26/2021 11:10:10PM via free access 246 J. D. 0'Shea and C. S. Lee depended on the proximity of the uterus to the ovary. However, subsequent experiments involving reapposition of the uterus to the contralateral (Butcher, Barley & Inskeep, 1969) or ipsilateral (O'Shea & Lee, 1972a) ovary have failed to restore the normal duration of pseudopregnancy, suggesting that spatial separation is not an essential feature. Clemens, Minaguchi & Meites (1968) were able to prolong pseudopregnancy in the rat simply by ligating blood vessels 'joining the uterus to the ovary', and similar effects have been reported in the guinea-pig (Bland & Donovan, 1969) and sheep (Dobrowolski & Hafez, 1970). In view of recent theories on the rôle of connections between the uterine and ovarian blood vessels in the mediation of local uterine luteolytic activity (Phar- riss, 1970; McCracken, Baird & Goding, 1971), further clarification of the basis for prolongation of luteal life-span following interruption of utero-ovarian connections is desirable. This paper describes experiments concerned with defining more precisely the effects on the duration of pseudopregnancy of section of the various structures connecting the ovary and uterus in the rat. MATERIALS AND METHODS General Female Hooded Wistar rats aged 8 weeks were used in two experiments. Pseudopregnancy was induced by sterile mating with vasectomized males, which remained caged with the females throughout the experiments. Vaginal smears were taken daily for 9 days before the introduction of males to select females showing normal oestrous cyclical activity. Only rats showing an oestrous cycle length of 4 to 6 days before the first pseudopregnancy were included in the experiments. Vaginal smears were continued daily throughout the experi¬ ments. All surgery was performed bilaterally under ether anaesthesia through a ventral mid-line incision. Operations were performed on Day 6 of pseudo¬ pregnancy in all rats, Day 0 being designated the first day of vaginal oestrus. The termination of pseudopregnancy was recognized by the return of vaginal oestrus. Experiment 1 The effects of section of the uterine tube (Text-fig. 1, a), the mesosalpinx and broad ligament (Text-fig. 1, b) and the anterior uterine artery and vein (Text-fig. 1, c) on the duration of pseudopregnancy were studied in a factorial experiment. Sixty-four rats, randomly allocated to eight groups each of eight rats (Table 1), were maintained throughout two consecutive pseudopreg- nancies. Rats in the control group (Group I) were subjected to laparotomy and handling of both uterine horns. Section of the uterine tube involved prior ligation with 4/0 monofilament nylon immediately above and below the site of section, which was performed close to the uterotubal junction (Text-fig. 1, a). Free ends of the two ligatures were then tied to one another to restore as far as possible the normal positional relationship between the uterus and ovary. Downloaded from Bioscientifica.com at 09/26/2021 11:10:10PM via free access Section of rat utero-ovarian vascular connections 247 Section of the anterior uterine artery and vein, between the point of origin of these vessels from the utero-ovarian vessels and the point at which the first uterine branches arose (Text-fig. 1, c), was performed after ligation on either side of the point of section. The mesosalpinx and broad ligament were cut without ligation. On the first day of dioestrus following the end of the second pseudopregnancy, four rats from each group were anaesthetized and 0-5 to 10 ml of Indian ink (Pelikan) was injected into the left saphenous vein. After 2 to 5 min, these rats were killed with an overdose of chloroform. The uterine horns were pinned out to expose the blood vessels in the mesovarium and broad ligament. The ab¬ dominal contents were then fixed in situ in 10% formalin. After fixation, the entire genital tracts of these rats were dissected out, dehydrated in alcohol and cleared in xylene to permit examination of their blood vessels. Text-fig. 1. Diagramatic representation of one side of the female genital tract of the rat, together with its accompanying blood vessels. The sites of section of the Fallopian tube (a), the mesosalpinx and broad ligament (b), and the anterior uterine vessels (c) in Exp. 1 are indicated. Ov == ovary; Ut = uterine horn. Experiment 2 Four groups each of twenty-one rats (Table 3) were used in an experiment to differentiate the effects of section of the anterior uterine artery from those of section of the anterior uterine vein. Section of these vessels, individually or in combination, was performed at the same site as in the previous experiment, following ligation on both sides of the point of section. Rats in the control group (Group I) were subjected to laparotomy, handling of the uterus, and puncture of the mesosalpinx on both sides of the anterior uterine vessels. Puncture was performed in the same manner as that used to pass ligatures around these vessels in the experimental groups. All rats in the experimental groups, and fourteen control rats, were injected with Indian ink on the first day of dioestrus following the end of the second pseudopregnancy, using the technique described previously. In addition to the groups described above, a further six rats were subjected to section of the anterior uterine artery and six to section of the anterior uterine vein. Four rats from each group of six were injected with Indian ink 7 days Downloaded from Bioscientifica.com at 09/26/2021 11:10:10PM via free access 248 J. D. 0'Shea and C. S. Lee after section to study the condition of the blood vessels. The remaining two rats from each group were killed 5 days after operation (on Day 11 of pseudo¬ pregnancy) and their uteri examined grossly and histologically for evidence of deciduoma formation. Material for histological examination was fixed in 10% buffered neutral formalin, and embedded in paraffin wax. Sections were stained with haematoxylin and eosin (H and E). Complete cross sections from the anterior, middle and posterior thirds of each uterine horn were examined. Histological examination of the anterior uterine vessels and mesosalpinx at the site where section would normally have been performed was carried out on a final additional group of five normal female rats. Tissues from these rats were fixed in Bouin's fluid and embedded in paraffin wax, and sections were stained with H and E. Statistical analysis of data Data were analysed for statistical significance using Student's t test and analysis of variance (Sokal & Rohlf, 1969). RESULTS Experiment 1 The mean durations of two pseudopregnancies in each of the eight groups are shown in Table 1. Factorial analysis of variance (Table 2) showed that the only single factor to produce a significant lengthening of pseudopregnancy was section of the anterior uterine vessels (P<0-0\ in both pseudopregnancies). Table 1. Duration of pseudopregnancy in rats following section of utero- ovarian connections Structures sectioned Mean duration ofpseudopregnancy No. (days±S.E.M.) Group of Fallopian Mesosalpinx Anterior rats tube and broad uterine First Second ligament vessels pseudopregnancy pseudopregnancy I 13-5±0-42 13-5 + 0-57 II 13-8 ±0-49 12-6 + 0-18 III + 14-0 ±0-60 12-8±0-25 IV + 15-6 + 0-50 14-6 ±0-46 V + + 14-2 ±0-70 14-5 + 0-57 VI + + 14-9 + 0-52 14-1 ±0-35 VII + 15-0 ±1-00 14-4 ±0-46 VIII + + 15-8 ±0-45 14-6 + 0-65 Neither section of the uterine tube nor section of the mesosalpinx and broad ligament produced a significant effect.
Load more

Recommended publications
  • The Reproductive System
    27 The Reproductive System PowerPoint® Lecture Presentations prepared by Steven Bassett Southeast Community College Lincoln, Nebraska © 2012 Pearson Education, Inc. Introduction • The reproductive system is designed to perpetuate the species • The male produces gametes called sperm cells • The female produces gametes called ova • The joining of a sperm cell and an ovum is fertilization • Fertilization results in the formation of a zygote © 2012 Pearson Education, Inc. Anatomy of the Male Reproductive System • Overview of the Male Reproductive System • Testis • Epididymis • Ductus deferens • Ejaculatory duct • Spongy urethra (penile urethra) • Seminal gland • Prostate gland • Bulbo-urethral gland © 2012 Pearson Education, Inc. Figure 27.1 The Male Reproductive System, Part I Pubic symphysis Ureter Urinary bladder Prostatic urethra Seminal gland Membranous urethra Rectum Corpus cavernosum Prostate gland Corpus spongiosum Spongy urethra Ejaculatory duct Ductus deferens Penis Bulbo-urethral gland Epididymis Anus Testis External urethral orifice Scrotum Sigmoid colon (cut) Rectum Internal urethral orifice Rectus abdominis Prostatic urethra Urinary bladder Prostate gland Pubic symphysis Bristle within ejaculatory duct Membranous urethra Penis Spongy urethra Spongy urethra within corpus spongiosum Bulbospongiosus muscle Corpus cavernosum Ductus deferens Epididymis Scrotum Testis © 2012 Pearson Education, Inc. Anatomy of the Male Reproductive System • The Testes • Testes hang inside a pouch called the scrotum, which is on the outside of the body
    [Show full text]
  • Uterus – Dilation
    Uterus – Dilation Figure Legend: Figure 1 Uterus - Dilation of the uterine lumen in a female B6C3F1/N mouse from a chronic study. There is dilation of the uterine horn. Figure 2 Uterus - Dilation in a female B6C3F1/N mouse from a chronic study (higher magnification of Figure 1). The endometrial epithelium is cuboidal. Figure 3 Uterus - Dilation in a female B6C3F1/N mouse from a chronic study. There is dilation of the uterine lumen, which contains flocculent, eosinophilic material. Figure 4 Uterus - Dilation in a female B6C3F1/N mouse from a chronic study (higher magnification of Figure 3). There is flattened epithelium and eosinophilic material in the uterine lumen. Comment: Dilation of uterine horns (Figure 1, Figure 2, Figure 3, and Figure 4) is commonly observed at necropsy, and frequently these uteri have accumulations of excessive amounts of fluid within the 1 Uterus – Dilation lumen. Uterine dilation is relatively commonly seen in both rats and mice and may be segmental. Luminal dilation may be associated with stromal polyps or occur secondarily to hormonal imbalances from ovarian cysts or to a prolonged estrus state after cessation of the estrus cycle in aged rodents. Administration of progestins, estrogens, and tamoxifen in rats has been associated with uterine dilation. Luminal dilation is normally observed at proestrus and estrus in cycling rodents and should not be diagnosed. Increased serous fluid production is part of the proestrus phase of the cycle judged by the vaginal epithelium (which shows early keratinization covered by a layer of mucified cells) and should not be diagnosed. With uterine dilation, the endometrial lining is usually attenuated or atrophic and the wall of the uterus thinned due to the increasing pressure, but in less severe cases the endometrium can be normal (Figure 2).
    [Show full text]
  • Left Vaginal Obstruction and Complex Left Uterine Horn Communication in a 12 Year Old Female Barry E
    Perlman et al. Obstet Gynecol cases Rev 2015, 2:7 ISSN: 2377-9004 Obstetrics and Gynaecology Cases - Reviews Case Report: Open Access Left Vaginal Obstruction and Complex Left Uterine Horn Communication in a 12 Year Old Female Barry E. Perlman*, Amy S. Dhesi and Gerson Weiss Department of Obstetrics, Gynecology and Women’s Health, Rutgers - New Jersey Medical School, Newark, USA *Corresponding author: Barry E. Perlman DO, Department of Obstetrics, Gynecology and Women’s Health, Rutgers - New Jersey Medical School, MSB E-506, 185 South Orange Avenue, Newark, NJ 07101-1709, USA, Tel: 732 233 0997, E-mail: [email protected] Transabdominal pelvic sonogram revealed two prominent uterine Abstract cornua with an endometrial thickness of 3 mm in each horn. The Obstructive Müllerian duct anomalies are an infrequently right cornu measured 11.4 x 2.0 x 3.6 cm and the left cornu measured encountered clinical problem. The use of imaging and surgical 10.4 x 2.8 x 4.1 cm. A 7 cm mass in the endocervical canal, concerning exploration allowed for diagnosis and treatment of symptoms of a for hematocolpos, represented an occlusion extending to the left complex obstructive müllerian anomaly. We present a case of a 12 vagina (Figure 1). year old female with a history of intermittent lower abdominal pain and absent left kidney who was found to have an obstructed left She underwent further imaging with two MRI studies that were vagina and complex left uterine horn communications resulting in mutually inconclusive and inconsistent in regards to her pelvic hematocolpos, hematometra, and endometriosis.
    [Show full text]
  • 39Th Annual Residents Paper Day and 32Nd Annual Philip J. Disaia Society Symposium Friday, May 7, 2021
    Proudly presents the 39th Annual Residents Paper Day and 32nd Annual Philip J. DiSaia Society Symposium Friday, May 7, 2021 Visiting Professor and Moderator Richard J. Paulson, MD Professor of Obstetrics & Gynecology, Alia Tutor Chair in Reproductive Medicine, Chief of the Division Reproductive Endocrinology and Infertility, and Director of USC Fertility, Keck School of Medicine of USC Table of Contents CME Activity Statement ....................................................................................................................................................... 3 Disclosure Statement ........................................................................................................................................................... 4 Welcomes Our Visiting Professor and Moderator ........................................................................................................... 5 Previous Annual Residents Paper Day Visiting Professors and Moderators .................................................... 6 Acknowledgements .............................................................................................................................................................. 7 Agenda ................................................................................................................................................................................... 8 Junior Residents ...............................................................................................................................................8
    [Show full text]
  • 1 Ultrasound Monitoring of Embryonic, Follicular, and Uterine
    Ultrasound Monitoring of Embryonic, Follicular, and Uterine Dynamics of Early Pregnancy in the Alpaca Sara Brunsden Introduction: The alpaca, Vicuna pacos, is a member of the Camelidae family, along with llamas, guanacos, vicunas, and Bactrian and Dromedary camels. Traditionally found in the altiplano of South America, the popularity of the alpaca has caused it to spread all over the world, including here in the United States. In South America, they are predominantly used for their fleece, while the industry here revolves mainly around breeding. However, relatively little is known about the reproduction of the alpaca. It is the overall goal of this study to discover more about the gestation of the female, specifically the embryonic stage from conception to forty days of pregnancy. Like the rabbit and cat, the alpaca is an induced ovulator, meaning that the act of copulation triggers the female to ovulate. Differing information has been presented on whether alpacas have waves of follicular development similar to other mammalian species. According to studies by Bravo (1991) and Sumar (2000), the follicles grow, mature, and regress in a distinct pattern. However, a study by Donovan (2011) at the University of Massachusetts Amherst did not find a pattern of definitive follicular waves. Alpacas are considered to have a low fertility rate compared to other domesticated mammals, with the highest rate of early embryonic death (EED) occurring within the first month of pregnancy, possibly due to weak maternal fetal tissue associations (Olivera 2003). The rate of EED has been suggested to be as high as 58% (Fernandez-Baca 1970), with 44% occurring before Day 27 (Ratto 2011).
    [Show full text]
  • The Ovarian and Uterine Arteries in the Chinchilla (Chinchilla Lanigera)
    Article — Artikel The ovarian and uterine arteries in the chinchilla (Chinchilla lanigera) A Çevik-Demirkana*, V Özdemira and I Demirkanb from the Center for Experimental Medi- ABSTRACT cine, Research and Application, Afyon The purpose of this study was to describe arteries supplying the ovaries and uterus in the chinchilla. Five healthy adult female chinchillas were used. In order to reveal the arterial Kocatepe University, Turkey, were used network by dissecting under a stereoscopic microscope, latex coloured with red ink was in this study. The live body weight of injected through the common carotid artery. The ovaries of the chinchilla are supplied by chinchillas varied between 450 g and the arteriae ovaricae which formed end-to-end anastomoses with the cranial termination of 500 g. The animals were euthanased by 7 the arteria uterina. Soon after leaving the aorta abdominalis, the arteriae ovaricae extended the methods described by Flecknell . 2–3 mm caudolaterally, then released 1 branch and extended caudally and bifurcated into 2 Regulations of the ethical committee further branches. One of these supplied branches to fat tissue. The other branch coursed of Afyon Kocatepe University were fol- caudally and anastomosed with the arteria circumflexa ilium profunda and dispersed into fat lowed. Following euthanasia, 1 m of tissue. The arteria ovarica further subdivided into 2 rami ovaricae. The origins of the uterine heparine sodium (Nevparin, Mustafa arteries were exclusively from the left arteria iliaca externa. The arteria uterina gave a branch Nevzat, Istanbul, Turkey) was imme- to the arteria umbilicalis and consecutive branches which supplied to the ureter, urinary diately injected via the jugular vein to pre- bladder and cranial aspects of the vagina.
    [Show full text]
  • Abdominal Total Hysterectomy: the Modified Aldridge's Procedure With
    Published online: 2018-11-19 THIEME S22 Precision Surgery in Obstetrics and Gynecology Abdominal Total Hysterectomy: The Modified Aldridge’s Procedure with Noda’sMethod Yoh Watanabe, MD, PhD1 1 Department of Obstetrics and Gynecology, Tohoku Medical and Address for correspondence Yoh Watanabe, MD, PhD, Department of Pharmaceutical University, Sendai, Japan Obstetrics and Gynecology, Tohoku Medical and Pharmaceutical University, 1-15-1, Fukumuro, Miyagino-ku, Sendai 983-8536, Japan Surg J 2019;5(suppl S1):S22–S26. (e-mail: [email protected]). Abstract Although laparoscopic surgery or robotic surgery has recently been the main proce- dure adopted for managing benign uterine tumors, abdominal total hysterectomy must still be learned as a basic surgical skill for obstetricians and gynecologists. Total hysterectomy is divided into two types: the extrafascial and intrafascial approaches. Intrafascial hysterectomy, represented by the Aldridge’s method, is a useful and safe procedure for treatment when the patient has no cervical malignancy, including cervical intraepithelial neoplasia. Furthermore, the intrafascial approach is safely performedeveninpatientswithfirm adhesion in the Douglas’s pouch and/or around the uterine cervix due to endometriosis, pelvic inflammatory diseases, or a history of intrapelvic surgery. The intrafascial approach can also effectively prevent descent of Keywords the vaginal stump after hysterectomy via the partial preservation of the uterine ► abdominal retinaculum. Although the Aldridge’s method was originally reported to start via an hysterectomy intrafascial approach at the position of the internal cervical os using scissors, Dr. ► intrafascial method Kiichiro Noda created a modified version of the procedure that increases its ease and ► Aldridge’s procedure safety by changing the position and management of the parametrial tissue including ► gynecologic surgery the uterine artery.
    [Show full text]
  • Ovarian Differences Cow Mare
    Animal/Dairy Science 434 Female comparative anatomy; History of Reproductive Physiology Ovarian Differences Cow Mare Sow Cow Cow, Sow, Ewe, Human Sow • Cortex on outside • Ovulation can occur on any point of the ovary Preovulatory Tertiary Follicle Mare Blood vessels and connective tissue in medulla • Inversion of the cortex and medulla • Ovulation occurs at the Ovulation Fossa Internal CL Cow Mare Rabbit, Oposum Duplex Mouse 2 Uterine Horns 2 2 Cervixes 1 Vaginas Vagina Uterine and Cervical Differences Cow Sow Mare Cow Bicornuate Sow Ewe Smaller uterine horns 1 Vagina 1 Cervix Large 1 Uterine Body uterine 2 Uterine Horns horns Bicornuate Mare Large uterine body 1 Vagina Smaller uterine horns 1 Cervix 1 Uterine Body 2 Uterine Horns Bicornuate Bitch (Canine) Queen (Feline) 1 Vagina 1 Cervix 1 Uterine Body 2 Uterine Horns Small uterine body Long uterine horns Simplex Woman Large uterine body 1 Vagina No uterine horns 1 Cervix 1 Uterine Body Human Tract Human Tract A 47-year old woman underwent a hysterectomy for excessively heavy menses. She had previously had four normal deliveries. This structure was removed, what is wrong? COW Uterine Body Internal Cervical Os • Cervix is composed of thick connective tissue • Mucus is secreted near the time of Cow has 4-5 breeding and annular rings ovulation. Cervix External Cervical Os Vagina Uterine Body Uterine Body Longitudinal Mare Folds Sow No obstacles Interdigitating pads No fornix vagina Fornix Vagina Vagina Vagina Cervical Folds Cervix FV IP Sow Mare External Genitalia Sow Mare Cow Ewe What
    [Show full text]
  • MRI Anatomy of Parametrial Extension to Better Identify Local Pathways of Disease Spread in Cervical Cancer
    Diagn Interv Radiol 2016; 22:319–325 ABDOMINAL IMAGING © Turkish Society of Radiology 2016 PICTORIAL ESSAY MRI anatomy of parametrial extension to better identify local pathways of disease spread in cervical cancer Anna Lia Valentini ABSTRACT Benedetta Gui This paper highlights an updated anatomy of parametrial extension with emphasis on magnetic Maura Miccò resonance imaging (MRI) assessment of disease spread in the parametrium in patients with locally advanced cervical cancer. Pelvic landmarks were identified to assess the anterior and posterior ex- Michela Giuliani tensions of the parametria, besides the lateral extension, as defined in a previous anatomical study. Elena Rodolfino A series of schematic drawings and MRI images are shown to document the anatomical delineation of disease on MRI, which is crucial not only for correct image-based three-dimensional radiotherapy Valeria Ninivaggi but also for the surgical oncologist, since neoadjuvant chemoradiotherapy followed by radical sur- Marta Iacobucci gery is emerging in Europe as a valid alternative to standard chemoradiation. Marzia Marino Maria Antonietta Gambacorta Antonia Carla Testa here are two main treatment options in patients with cervical cancer: radical sur- Gian Franco Zannoni gery, including trachelectomy or radical hysterectomy, which is usually performed T in early stage disease as suggested by the International Federation of Gynecology Lorenzo Bonomo and Obstetrics (FIGO stages IA, IB1, and IIA), or primary radiotherapy with concurrent ad- ministration of platinum-based chemotherapy (CRT) for patients with bulky FIGO stage IB2/ IIA2 tumors (> 4 cm) or locally advanced disease (FIGO stage IIB or greater). Some authors suggested the use of CRT followed by surgery for bulky tumors or locally advanced disease (1).
    [Show full text]
  • In the Guinea-Pig
    Observations on the loss of catecholamine fluorescence from intrauterine adrenergic nerves during pregnancy in the guinea-pig C. Bell and S. J. Malcolm Department of Physiology, University of Melbourne, Parkville, Victoria 3052, Australia Summary. During unilateral pregnancy in the guinea-pig there is loss of formaldehyde\x=req-\ induced fluorescence from the adrenergic nerves supplying the uterus and its vascula- ture. This loss occurs initially near the site of implantation at about Day 20 of gestation and spreads progressively. Implantation of wax pellets containing progesterone into the uterine lumen or the gastrocnemius muscle of virgin guinea-pigs for 7 days produced loss of fluorescence from all local adrenergic nerves. No diminution of fluorescence was seen when pellets containing oestradiol were substituted. Chronic denervation studies showed that the adrenergic axons supplying the uterus and its arteries originated from both the ovarian artery and the pelvic region. Our results suggest that loss of adrenergic fluorescence within the uterus during pregnancy is due to an effect of placental pro- gesterone which is localized to the uterus because the high concentration of proges- terone necessary to cause fluorescence loss is not attained in the systemic circulation. Introduction In some species there is, during the course of pregnancy, a progressive disappearance of the charac¬ teristic formaldehyde-induced fluorescence normally associated with the adrenergic nerves of the uterus and its arterial supply. There is also a fall in the uterine content of noradrenaline. These declines have been observed in the guinea-pig (Sjöberg, 1968), rabbit (Rosengren & Sjöberg, 1968), man (Nakanishi, McLean, Wood & Burnstock, 1968) and dog (Ryan, Clark & Brody, 1974) and Bell ( 1972) has suggested that they constitute a protective mechanism against feto-placental ischaemia during generalized maternal sympathetic activation.
    [Show full text]
  • Understanding Mare Reproduction
    Know how. Know now. EC271 (Revised October 2011) UNDERSTANDING MARE REPRODUCTION Kathy Anderson Extension Horse Specialist University of Nebraska–Lincoln Extension is a Division of the Institute of Agriculture and Natural Resources at the University of Nebraska–Lincoln cooperating with the Counties and the United States Department of Agriculture. University of Nebraska–Lincoln Extension educational programs abide with the nondiscrimination policies of the University of Nebraska–Lincoln and the United States Department of Agriculture. © 1994-2011, The Board of Regents of the University of Nebraska on behalf of the University of Nebraska–Lincoln Extension. All rights reserved. UNDERSTANDING MARE REPRODUCTION Kathy Anderson Extension Horse Specialist University of Nebraska–Lincoln INTRODUCTION FUNCTIONAL ANATOMY Many producers who raise horses find breeding A correctly functioning reproductive tract is es- mares rewarding, yet frustrating. Mares and stal- sential to the potential fertility of a broodmare. The lions are traditionally placed in the breeding herd tract goes through various changes as a mare exhib- due to successful performance records, with little its estrous cycles. A good working knowledge of a consideration for their reproductive capabilities. mare’s anatomy and these changes will aid in early Horses are difficult breeders with an estimated identification of potential abnormalities. These foaling rate of below 60 percent. Various factors changes can easily be monitored through rectal pal- contribute to this, including long-erratic estrous pation or ultrasound by a veterinarian. cycles and an imposed breeding season that does The rectum is located above the reproductive not coincide with the mare’s natural breeding sea- tract allowing for a noninvasive examination of the son.
    [Show full text]
  • Uterine and Ovarian Countercurrentpathways in The Control of Ovarian Function in the Pig
    Printed in Great Britain J. Reprod. Pert., Suppl. 40 (1990), 179-191 ©1990 Journals of Reproduction & Fertility Ltd Uterine and ovarian countercurrentpathways in the control of ovarian function in the pig T. Krzymowski, J. Kotwica and S. Stefanczyk-Krzymowska Department of Reproductive Endocrinology, Centre for Agrotechnology and Veterinary Sciences, 10-718 Olsztyn, Poland Keywords: counter current transfer; ovary; oviduct; uterus; pig Introduction Countercurrent transfer of heat, respiratory gases, minerals and metabolites has been known for many years to be a fundamental regulatory mechanism of some physiological processes. In sea mammals, wading birds and fishes living in polar seas countercurrent systems in the limbs, flippers or tail vessels protect the organism against heat loss (Schmidt-Nielsen, 1981). In most mammals countercurrent heat exchange between the arteries supplying the brain and veins carrying the blood away from the nasal area and head skin forms the so-called brain cooling system, which protects the brain against overheating (Baker, 1979). The countercurrent transfer of minerals and metab- olites in the kidney is a well-known system regulating the osmolarity and concentration of urine (Lassen & Longley, 1961). Countercurrent transfers in the blood vessels of the intestinal villi take part in the absorption processes (Lundgren, 1967). The pampiniform plexus in the boar partici- pates in a heat-exchange countercurrent, thus decreasing the temperature of the testes (Waites & Moule, 1961), as well as in local transfer of testosterone (Free et al., 1973; Ginther et al., 1974; Einer-Jensen & Waites, 1977). Studies on the influence of hysterectomy on the function of the corpus luteum in different species, made in the 1930-1970s, suggested the existence of a local transfer of a luteolytic substance from the uterus to the ovary.
    [Show full text]