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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
191

Seasonal Changes in the Morphology of the Uterus of the Oviparous Lizard <em>Saproscincus mustelinus</em> and the Reproductively Bimodal Lizard <em>Saiphos equalis</em>.

Mathieson, Ashley Nicole 19 August 2009 (has links)
Among vertebrates, oviparity, a condition in which young at least partially develop outside the mother's body and are supported by yolk, is the ancestral state to viviparity, the reproductive mode in which embryos are fully developed at birth. Viviparity in reptiles is found only in the squamates. Among the more than 100 origins of viviparity in squamates, many have occurred fairly recently and as a result some species contain populations of both reproductive modes, i.e., are reproductively bimodal. The evolution of viviparity is associated with many changes including an increase in oviductal egg retention times, a decrease in thickness of the eggshell and a decrease in secretion of the uterine shell glands that are responsible for eggshell secretion. The uterine morphology of the oviparous Saproscincus mustelinus and the reproductively bimodal Saiphos equalis were compared to study the uterine shell gland cycle.
192

Effects of Ketoconazole on Uterine Weight and on Unbound Serum Estradiol Relative to Vaginal Cornification in Rats

Hall, Leonard L. 01 May 1990 (has links)
Ketoconazole is a broad-spectrum antifungal with oral activity and is documented to block steroid biosynthesis in fungi and mammals. Estradiol-primed ovariectomized rats lose the estradiol-induced, cornified layer of the vaginal epithelium as a result of ketoconazole treatment. This effect is not explained by current knowledge of ketoconazole's mechanism of action. Ketoconazole's effect on estradiol's binding to either receptors in target tissues (target-cell receptors) or serum-estradiol-carrying proteins in the aforementioned rats was investigated. The uterus is responsive to estradiol treatment, which causes an increase in uterine size and weight. This tissue is a sensitive means of studying the effects of ketoconazole on target-cell estradiol receptors. Tamoxifen, documented to block the effects of estradiol by binding to target-cell estradiol receptors, was used as a control drug. Uterine weight and horn diameter were measured in estradiol-treated, ovariectomized rats after 7 days of oral, twice-a-day, drug treatment. Ketoconazole had no effect on mean uterine weights and uterine horn diameters at any of the doses tested; however, tamoxifen at a dose of 10 mg/kg caused a significant reduction in uterine weight and horn diameter. Vaginal histopathology showed that ketoconazole and tamoxifen caused decornification. The percentage of unbound estradiol in the serum was measured in estradiol-treated, ovariectomized rats treated with ketoconazole orally, twice-a-day for 3 days to determine the effects of ketoconazole on the serum binding of estradiol. The results of vaginal cytology showed that ketoconazole caused normal decornification. In comparison with control animals, the results of the serum percent-unbound estradiol assays showed that ketoconazole caused a dose-related increase in the percent-unbound estradiol in the blood. The dose required to cause a 5 percent increase in serum unbound estradiol was approximately 6 times greater than the minimum dose required to cause decornification. Ketoconazole's effects on target-cell estradiol receptors and serum estradiol-carrying proteins do not appear to have any relationship to its effects in causing vaginal decornification in this model.
193

Inhibiting the IGF-1 receptor with the cyclolignan Picropodophyllin: an in vitro study of ovulation, implantation and receptivity in a mouse model

Larsson, Patrik January 2008 (has links)
Picropodophyllin (PPP) is an analogue of the anti tumour lignan podophyllotoxin with the unique ability to selectively inhibit the receptor of Insulin like growth factor 1(IGF-1). IGF-1 is believed to play an important part in development of the endometrium facing implantation. With PPP treated mice, studies can be made to measure gene expression from tissue of both treated and untreated mice to compare the role of IGF-1 regarding ovulation, implantation and receptivity. The aim of this study was to analyze gene expression of some steroid hormone receptors and cytokines in ovaries from mice treated with PPP. In this study, seven mice were treated with PPP at different times and tissue was collected. PCR-primers for cDNA sequences of estrogene receptor α, estrogene receptor β, progesterone receptor A, progesterone receptor B, growth hormone receptor, interleukin 1 α, interleukin 1 β, tumour necrosis factor α and androgen receptor were used. Real Time PCR was run with the samples and gene expression was measured. The results of this study showed that the inhibition of IGF-1 receptor interacted with IGF-1 which lead to altered levels of estrogene receptor alpha, progesterone receptor, growth hormone receptor and androgen receptor that can decrease ovulation. The results also showed the differences in gene products between treated and untreated samples, suggesting that IGF-1 plays an important role regarding ovulation. / Studier med hjälp av den selektiva insulinlika tillväxtfaktor 1 receptorn (IGF-1R) antagonisten; picropodof?phyllin (PPP), hur samspelet mellan livmoderslemhinnan och implantationsprocessen, samt hur ovulationen påverkas av insulinlika tillväxtfaktorn 1 (IGF-1) kan nu utföras. IGF-1 tros ha en viktig roll för den reproduktiva processen, där den påverkar ovulation, implantation och embryoutveckling. IGF-familjen består av tre ligander; insulin, IGF-1 och IGF-2. IGF transporteras bundet till bindarprotein (IGFBP). Medlemmarna i IGF receptorfamiljen kan binda IGF-1, IGF-2 och insulin fast med olika affinitet. PPP som är en cykloligan, är en analog från podofyllotoxin och fungerar som en syntetisk IGF-1 receptorantagonist, som selektivt inhiberar receptorns aktivitet. PPP tros även kunna nedreglera genexpression av receptorn. Tre tidigare projektarbeten har utförts på vävnader från möss injicerade med PPP. Tyngdpunkterna i dessa arbeten har legat på immunhistokemiska studier av IGF-1 i reproduktionsorgan från möss, uttryck av IGF-1, dess receptor och bindarprotein 1 i ovarier och uterus efter behandling med PPP. I denna studie användes vävnad samt cDNA från sju möss behandlade med PPP, i olika stadier av reproduktionen samt även icke behandlade möss. Studiens syfte var att med sanntids-PCR jämföra genuttryck från östrogenreceptor α och β, progesteronreceptor A och B, tillväxthormonreceptor, Interleukin 1 α och β, ’tumor necrosis’ faktor α samt androgenreceptor i vävnad från PPP-behandlade och obehandlade möss och genom de erhållna resultaten från ovarievävnaden utläsa effekten på ovulationen och från uterusvävnaden effekten på implantation och receptivitet. Studieresultaten visade att IGF-1s frånvaro gav förändrade nivåer av genprodukter, som medförde minskad ovulationen. Studien visade att IGF-1s roll vid ovulationen var väsentlig.
194

Nutrient Signaling, Mammalian Target of Rapamycin and Ovine Conceptus Development

Gao, Haijun 2009 May 1900 (has links)
This research was conducted to test the hypothesis that select nutrients including glucose, leucine, arginine and glutamine stimulate conceptus development by activating mTOR (mammalian target of rapamycin; HGNC approved gene name: FRAP1, FK506 binding protein 12-rapamycin associated protein 1) signaling pathway. First, temporal changes in quantities of select nutrients (glucose, amino acids, glutathione, calcium, sodium and potassium) in uterine lumenal fluid from cyclic (Days 3 to 16) and pregnant (Days 10 to 16) ewes were determined. Total recoverable glucose, Arg, Gln, Leu, Asp, Glu, Asn, His, beta-Ala, Tyr, Trp, Met, Val, Phe, Ile, Lys, Cys, Pro, glutathione, calcium and sodium was greater in uterine fluid of pregnant compared to cyclic ewes between Days 10 and 16 after onset of estrus. Of note were remarkable increases in glucose, Arg, Leu and Gln in uterine flushings of pregnant ewes between Days 10 and 16 of pregnancy. Second, effects of the estrous cycle, pregnancy, progesterone (P4) and interferon tau (IFNT) on expression of both facilitative (SLC2A1, SLC2A3 and SLC2A4) and sodium-dependent (SLC5A1 and SLC5A11) glucose transporters, cationic amino acid transporters (SLC7A1, SLC7A2 and SLC7A3), neutral amino acid transporters (SLC1A4, SLC1A5, SLC3A1, SLC6A14, SLC6A19, SLC7A5, SLC7A6, SLC7A8, SLC38A3, SLC38A6 and SLC43A2) and acidic amino acid transporters (SLC1A1, SLC1A2 and SLC1A3) in ovine uterine endometria from Days 10 to 16 of the estrous cycle and Days 10 to 20 of pregnancy as well as in conceptuses from Days 13 to 18 of pregnancy were determined. Among these genes, SLC2A3 and SLC7A6 were detectable only in trophectoderm and endoderm of conceptuses. The abundance of mRNAs for SLC2A1, SLC2A4, SLC5A1, SLC5A11, SLC7A1, SLC7A2, SLC1A4, SLC1A5, SLC43A2 and SLC1A3 changed dynamically in ovine uterine endometria according to day of the estrous cycle and early pregnancy. Expression of mRNAs for SLC2A1, SLC5A11 and SLC7A1 in endometria was induced by P4 and further stimulated by IFNT with shortterm treatment (12 days), while expression of SLC7A1 and SLC1A5 in endometria required long-term treatment (20 days) with P4 and IFNT. Third, effects of the estrous cycle, pregnancy, P4 and IFNT on expression of nitric oxide synthase (NOS1, NOS2 and NOS3), GTP cyclohydrolase (GCH1), ornithine decarboxylase 1(ODC1), insulin-like growth factor II (IGF2), FRAP1 complexes (FRAP1, LST8, MAPKAP1, RAPTOR, RICTOR), regulators (TSC1, TSC2, RHEB) and an effector (EIF4EBP1) of FRAP1 signaling in ovine uterine endometria from Days 10 to 16 of the estrous cycle and Days 10 to 20 of pregnancy as well as in conceptuses from Days 13 to 18 of pregnancy were determined. All of these genes were expressed in ovine uterine endometrium and conceptuses. Among these genes, expression of NOS1, IGF2, RHEB and EIF4EBP1 changed dynamically due to day of the estrous cycle and early pregnancy. Progesterone stimulated NOS1 and GCH1 expression while IFNT inhibited NOS1 expression in uterine endometria, and P4 and IFNT stimulated expression of RHEB and EIF4EBP1 in uterine endometria. Collectively, these results indicate that: 1) the availability of select nutrients in the ovine uterine lumen increases to support the rapid growth and elongation of the conceptus during the peri-implantation stage of pregnancy; 2) P4 and/or IFNT stimulate(s) glucose and amino acid transporters to facilitate their transport from maternal tissues and/or blood into the uterine lumen during early pregnancy; 3) the FRAP1 cell signaling pathway mediates interactions between the maternal uterus and peri-implantation conceptus and both P4 and IFNT affect this pathway by regulating expression of RHEB and EIF4EBP1. Expression of NOS, ODC1 and IGF2 appear to be linked to FRAP1 signaling in both uteri and peri-implantation conceptuses.
195

Transcriptional Regulation of Galectin 15 (LGALS15): An Implantation-Related Galectin Uniquely Expressed in the Uteri of Sheep and Goats

Lewis, Shaye K. 2009 August 1900 (has links)
Galectins are a family of secreted animal lectins with a high affinity to betagalactosides commonly involved in cellular functions such as apoptosis, adhesion and migration. Galectin 15 (LGALS15), a newest member of the galectin superfamily, has a unique C-terminal RGD sequence and participates in integrin-mediated ovine trophectoderm cell attachment and migration. In the ovine uterus, LGALS15 is expressed only by the endometrial luminal (LE) and superficial glandular (sGE) epithelia, induced by progesterone between Days 10 and 12 of the cycle and pregnancy, and then stimulated by interferon tau (IFNT) from the conceptus after Day 14 of pregnancy. During early pregnancy, the canonical janus kinase-signal transducer and activator of transcription (JAK-STAT) pathway is not active in the endometrial LE/sGE. Therefore, IFNT may utilizes a non-canonical signaling pathway to increase transcription of genes, including CST3, CTSL, HIF2A, LGALS15, and WNT7A, specifically in the endometrial LE/sGE. Alternatively, IFNT and progesterone could indirectly affect epithelial gene expression by influencing gene expression in the stroma, which then communicates with the epithelium. Although the LGALS15 gene is present in ovine, caprine and bovine species, it is only expressed in uteri of sheep and goats. Available data shows a tissue- and speciesspecific expression pattern for LGALS15, likely involving multiple layers of transcription regulation in the ruminant endometrium. Further analysis of the LGALS15 5? promoter/enhancer region revealed similar predicted transcription factor binding sites in all three species, including; PU.1, Ets-1, AP1, Sp1, and GRE or PRE sites. Interestingly, the proximal promoter region of the LGALS15 gene in all three species exhibited a conserved Sp1 binding site upstream of an AP1 binding site on both sense and antisense strands, and with similar spacing between binding sites. Sequence analysis revealed key differences in LGALS15 gene structure between ruminant species including the proximity of repetitive DNA sequences to the transcription start site (+1). Bovine LGALS15 has repetitive DNA sequences start at - 145 whereas in ovine or caprine LGALS15 it starts at about -300. The length of the repetitive DNA sequence is similar (~1.2 kb) in the 5' promoter/enhancer region of LGALS15 in all three species. Transient transfection analyses found that repetitive DNA sequences reduced basal promoter activity and responsiveness to treatments. None of the promoter construct showed responsiveness to interferon tau (IFNT). The bovine LGALS15 gene promoter showed no activity under any experimental conditions. The current studies indicate that uterine LGALS15 is expressed in ovine and caprine but not bovine species. Additionally, repetitive DNA sequences found in the promoter region may contribute to modulating the LGALS15 gene expression. Therefore, the ruminant LGALS15 gene, like other galectins, is under tight transcriptional control involving hormones, requisite transcription factors and potentially chromatin remodeling complexes working synergistically for LGALS15 promoter transactivation.
196

Placental Localization and Perinatal Outcome

Goddard Kalanithi, Lucy Emily 25 March 2008 (has links)
This retrospective case-control study was designed to investigate the relationship between placental localization and intrauterine growth restriction (IUGR). Pregnant women with an anatomic survey from January 1, 2000, to December 31, 2005, and delivery of the pregnancy at Yale-New Haven Hospital (YNHH) were identified using clinical and billing records. Multiple gestation, fetal anomaly, and incomplete medical information were reasons for exclusion. Cases (N=69) were consecutive pregnancies with evidence of IUGR (estimated fetal weight <10th percentile for gestational age) at last follow-up ultrasound. Randomly selected controls (N=258) from the same time period had no evidence of IUGR. Maternal, ultrasound, delivery, and perinatal data were collected by retrospective medical record review, and IUGR cases and non-IUGR controls were compared using the Students t-test, Wilcoxon test, Chi-square analysis, Fishers exact test, and ANOVA. Placental location was determined from the anatomic survey record (obtained at 18.4 ± 1.2 weeks gestation in the IUGR group and 18.2 ± 1.0 weeks gestation in the control group; P=0.18). Multivariate logistic regression with adjustment for confounders was used to investigate the association between IUGR and placental localization. Consistent with known predictors of IUGR, the IUGR group had a higher proportion of black women (36.4% vs. 19.8%, P=0.03), chronic hypertension (26.0% vs. 3.5%, P<0.001), and hypertensive disorders of pregnancy (36.2% vs. 5.0%, P<0.001). Mean birth weights of IUGR and non-IUGR pregnancies differed by 2 kilograms (3244 ± 625 grams vs. 1277 ± 637 grams, P<0.001). IUGR infants were more likely to receive antenatal steroids, deliver preterm, deliver by cesarean section, and be admitted to neonatal intensive care. In both IUGR and non-IUGR pregnancies, the placenta was most commonly anterior or posterior. Unilateral placentas were three times more common in the IUGR group than in the non-IUGR group (17.4% vs. 5.0%, P=0.01). IUGR pregnancies were over four times as likely as control subjects to have unilaterally-located placentas compared to anterior placentas (OR 4.8, 95% confidence interval, 1.9-11.7). Adjusting for ethnicity, chronic hypertension, and hypertensive disorders of pregnancy did not affect this finding (OR 4.6, 95% confidence interval 1.6-13.5). In conclusion, we compared a group of 69 IUGR pregnancies to 258 non-IUGR controls and found intrauterine growth restriction to be associated with unilateral placentation.
197

Progesterone related cellular change in the uterine cervix with particular reference to progesterone-only contraceptives.

McCallum, Shan Merrell. January 1993 (has links)
This study examines the effect of progesterone-only injectable contraceptives, and medroxyprogesterone acetate (Depo-Provera) in particular, on the cells of the uterine cervix. Cervical and vaginal smears were taken before commencement of therapy and at 3 and 6 month intervals thereafter on 79 asymptomatic women attending a family planning clinic. Results of hormonal and cellular measurements before and after therapy were compared. menstrual cycling was also studied. The effect on Methods used were hormonal maturation indices, image analysis measurements and microscopic observation of cellular . features. The latter included anisocytosis, anisokaryosis, karyomegaly , plaque formation, cytoplasmic wrinkling, nuclear grooving, hypertrophy, atrophy, cytoplasmic moulding and density, retarded maturation and nuclear protrusions. Squamous, endocervical and metaplastic cells were examined. Analysis of the results showed that progesterone-only contraceptives produce all of the above to a greater or lesser degree resulting in an increased relative nuclear area which may be confused with intraepithelial neoplasia. This is due to the production of a folate deficiency at target organ level which interferes with cell division and slows the maturation process. This effect enabled further observations to be made leading to the establishment of the origin and content of the nipple-like protrusions which occur in endocervical cells in response to hormonal activity. Physiological effects included amenorrhoea and irregular menstrual cycling. Most women showed evidence of interference with normal cycling to a varying degree. The documented cellular changes were shown to modify the expression of common inflammatory and neoplastic conditions of the uterine cervix. These included trichomoniasis, herpesvirus cervicitis, human papillomavirus infection, folate deficiency, cervical intraepithelial neoplasia and invasive carcinoma as well as multiple pathologies. The potential for diagnostic error was examined. New diagnostic criteria were formulated based on the comparison of cellular features found in the presence of the contraceptive with those found under normal conditions. It is anticipated that these criteria will facilitate the cytological diagnosis of pathological conditions of the uterine cervix in users of depo-medroxyprogesterone acetate (DMPA), leading to increased accuracy and improved and better directed patient management. / Thesis (M.Med.Sc.)-University of Natal, Durban, 1993.
198

Molecular response of the endometrium to bacterial infection in dairy cattle

Swangchan-Uthai, Theerawat January 2012 (has links)
No description available.
199

Kačių ovariohisterektomijos statistinių duomenų ir gimdos bei kiaušidžių patomorfologinių tyrimų analizė / The analysis of feline ovariohysterectomy statistics and ovarian and uterus pathomorphological researches

Gželko, Marina 05 March 2014 (has links)
Darbas atliktas Lietuvos Sveikatos Mokslų Universiteto Veterinarijos Akademijos Patologijos centre nuo 2012 metų sausio iki 2013 metų spalio mėnesio. Darbo tema: Kačių ovariohisterektomijos statistinių duomenų ir gimdos bei kiaušidžių patomorfologinių tyrimų analizė. Tyrimo tikslas - atlikti kačių ovariohisterektomijos statistinių duomenų ir gimdos bei kiaušidžių patomorfologinių tyrimų analizę. Tyrimo tema aktuali dėl vis didėjančio kačių reprodukcijos susidomėjimo, siekiant susilaukti sveikų palikuonių. Tyrimų objektas – katės (patelės, Felis catus), kurioms buvo atlikta OHE. Ištirti 227 kačių organai (n=227), ir apklausius jų šeimininkus, surinkti statistiniai duomenys. Vertinamos kiaušidės ir gimda, jų topografija, dydis, spalva, konsistencija, kvapas ir forma. Organai vertinami iš išorės, vėliau pjūvyje. OHE metu, įtarus patologijas, paimti kiaušidžių ir gimdos mėginiai histopatologiniam tyrimui. Ištirta 16 kačių kiaušidžių ir 13 gimdų. Mėginiai dažyti hematoksilinu ir eozinu. Kiaušidžių ir gimdos patologijos katėms diagnozuojamos retai (apie 7 proc.) ir dauguma aptinkamos rutininės OHE metu. Kiaušidėse dažniausiai aptinkami pakitimai - cistos, gimdoje - piometra. Vidutinis kačių, sergančių piometra amžius - 6 metai. Statistiniai duomenys apskaičiuoti Microsoft Office Excel 2007. Darbo apimtis - 56 puslapiai, naudoti 47 literatūros šaltiniai, 6 lentelės, 34 paveikslai. / This work was carried out in the period of 2012 January to 2013 October at the Pathology Center of the Veterinary Academy of the Lithuanian University of Health Sciences. The title of work is “The analysis of feline ovariohysterectomy statistics and ovarian and uterus pathomorphological researches”. The aim of the study: to perform cats OHE statistics and ovarian and uterus pathomorphological investigations analysis. The research theme is relevant due to increasing interest in feline reproduction, in order to have healthy offsprings. The object of study is the cats (female, Felis catus), which has been conducted OHE. There were examined 227 cats ovaries and uterus. Pet's owners were interviewed in order to get statistical data. Topography, size, color, texture, smell and shape of ovaries and uteruses were estimated. Organs were examined from the outside, later in the section. Samples for histopathological examination were taken due to suspected pathology. There were tested 16 cats ovaries and 13 uteruses. They were stained by hematoxylin and eosin. Cats ovary and uterus pathology are rare (about 7%) and diagnosed mostly by daily OHE. Cysts mostly are diagnosed in ovaries, in uterus – pyometra. Average age of cats with pyometra is 6 year. Average age of cats, which was operated – 30 months. OHE is performed to terminate cats reproduction. Statistical data analysis was rated by Microsoft Excel 2007. The volume of work is 56 pages, 6 tables and 34 pictures. Total count of... [to full text]
200

Untersuchungen zur Reproduktionsleistung von Feldhäsinnen / gleichzeitig ein Beitrag zur Ursachenfindung des Populationsrückganges dieser Wildtierart

Bensinger, Sylvie 28 November 2004 (has links) (PDF)
Im Mittelpunkt dieser Untersuchung stand die Frage, inwieweit der Feldhasenrückgang (Lepus europaeus) auf eine verminderte Reproduktion zurückzuführen ist. Zur Klärung dieser Frage wurden dabei erstmals in Deutschland die jährliche Reproduktionsleistung von Häsinnen durch den Nachweis von Plazentationsstellen (BRAY, 1998), erfasst. Die Alterbestimmung erfolgte über die etablierte Methode der Augenlinsenwägung (ANDERSON u. JENSEN, 1972; SUCHENTRUNK, 1991). Die Probenentnahme erfolgte auf den jährlichen Feldhasenjagden in 15 verschiedenen Revieren in den Jahren 1997 und 1998 im Zeitraum Oktober bis Dezember. Untersucht wurden 311 Uteri, 183 von adulten und 128 von juvenilen Häsinnen. 84% der adulten Weibchen waren nachweislich reproduktiv, bei den Junghäsinnen (unter einem Jahr alte) lag der Anteil bei 0,8%. Alle Individuen der jüngsten Altersklasse der Adulten (1-1,5 Jahre) waren fortpflanzungsaktiv, während in der Klasse der 1,5-3 Jahre alte Tiere bereits nur noch 90% reproduziert hatten. Bei Häsinnen im Alter von 3-5 Jahren lag der Wert bei 86%. Bei der ältesten Klasse (> 5 Jahre) sank der Anteil deutlich auf 54% ab. Von den 30 nichtreproduktiven adulten Häsinnen wiesen 21 pathologische Uterusveränderungen auf. Auffällig war das hohe Durchschnittsalter der nichtreproduktiven, das bei über vier Jahren lag, im Vergleich zu den reproduktiven Tieren. Im Durchschnitt wurden 9,2 Plazentationsstellen pro Uterus bei den adulten Häsinnen (nichtreproduktive miteinbezogen) gezählt. Dieser Wert entspricht den aus der Literatur bekannten Angaben. Hinweise auf eine verminderte Fertilität weiblicher Tiere als Ursache für den kontinuierlichen Rückgang der Feldhasenpopulation und dessen gleichzeitige Überalterung konnten aus diesen Ergebnissen nicht abgeleitet werden. Zu vermuten sind erhöhte Sterblichkeitsraten von Junghasen als Ursache für den bedenklichen Rückgang der Feldhasenpopulation. / The present study focuses on the question, whether the decrease in numbers of European hares (Lepus europaeus) could be due to a decrease in reproduction within that species. In order to clarify this hypothesis, this study investigated the annual reproduction performance of female European hares by counting the number of placentation sites that have been detected with a method described by (BRAY, 1998). In addition, the females agea were determined using the established method of eye lens weight as an age index (ANDERSON u. JENSEN, 1972; SUCHENTRUNK, 1991). The analysis was carried out in the years 1997 an 1998. This field investigation is the very first study addressing this question in Germany. Uterine probes were sampled on the annual hares huntings from October to December. Reproduction performance was analysed in 311 uteri, with 183 from adult and 128 from juvenile animals, respectively. While 84% of the adult animals (age: more than 1 year) showed reproduction, in contrast only 0,8% of the juvenile female hares (age: less than 1 year) were reproductive. Within the group of the youngest adult female hares (age: 1 to 1,5 years) all animals showed reproduction performance, however, reproduction proved to be already reduced to 90% in the group of 1,5 – 3 years old animals. In the group of female hares in the age from 3 – 5 years 86% displayed a reproduction performance, while finally in the oldest adult female hares (age: more than 5 years) only 54% showed signs of reproduction. Interestingly, out of 30 adult female hares that showed no sign of reproduction, 21 animals in a age older than 4 years showed pathological uterine alterations. The average number of placentation sites per uteri was 9,2 (nonreproductives include). This value is consitant with reports from the literature. Therefore, it is unlikely that cause for the decrease in population within that wild life species is due to a reduce fertility of female European hares. It seems that the higher deathrate of young hares may be the cause for the decrease of hares population

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