H O Hoppen

University of Veterinary Medicine Hannover, Hanover, Lower Saxony, Germany

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Publications (47)48.73 Total impact

  • K. Franke · U. Meyer · H. Wagner · H.O. Hoppen · G. Flachowsky
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    ABSTRACT: The aim of the present study was to investigate the impact of various feed iodine supplementations up to the permitted maximum level in the EU, the effect of applying rapeseed meal (RSM) compared to a glucosinolate (GSL) free ration and the impact of two different iodine species (iodide, iodate) on milk, urinary, faecal and blood serum iodine as well as on T3 and T4 levels of blood. The results of the milk iodine are not completely shown but partly discussed in this paper. The study was conducted with 32 dairy cows, divided into 4 groups with 8 animals each. In two groups the cows were fed distillers dried grains with solubles (DDGS) as main protein source (16.5% of ration DM), in the other groups rapeseed meal (3.5 mmol GSL/kg) was applied. In each case half of the animals received feed with iodine in the form of potassium iodide, the other half as calcium iodate. Iodine supplementations of 0, 0.5, 1, 2, 3, 4 and 5 mg/kg DM were tested in consecutive periods of 21 days each. The supplementary iodine increased iodine contents of serum, urine and faeces. RSM application resulted in consistently higher iodine contents in the mentioned matrices just displaying significant differences at high supplementation levels. When feeding DDGS, at high iodine supplementations iodide caused higher serum and faecal iodine than iodate. Besides, the iodine species showed no consistent impact on the tested parameters. At the highest tested iodine supplementation (5 mg/kg DM) in the experimental groups (DDGS/iodide, DDGS/iodate, RSM/iodide, RSM/iodate) the iodine concentration of serum amounted to 234, 157, 334 and 361 µg/l, of urine to 1134, 1020, 2341 and 2513 µg/l and of faeces to 673, 354, 715 and 790 µg/kg fresh matter. At the same supplementation level T4 was significantly lowered. No impact was shown for the RSM application and the iodine species on T3 and T4. The results of the present study indicate that high iodine intakes not only cause strong increases in milk and urinary iodine but also lead to a considerable rise of iodine excretion via faeces. RSM in feed causes a shift of iodine normally excreted via milk to an excretion via urine and faeces accompanied by higher serum iodine.
    No preview · Article · Nov 2009 · Livestock Science
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    ABSTRACT: Concentrations of progesterone, prolactin and relaxin in serum at predetermined intervals after ovulation (day 0) in non-pregnant and pregnant normocyclic Beagles were assayed and results compared with those observed in German Shepherd dogs (GSD) in a previous study. The goal was to determine possible reproductive hormone specificities related to the GSD breed. Furthermore, the effects of medroxyprogesterone acetate (MPA)-treatment in non-pregnant Beagles and of progesterone supplementation in pregnant Beagles on the hormone concentrations were examined. Mean concentrations of progesterone and prolactin were not different in the non-pregnant Beagles compared with those seen in non-pregnant GSD, except at days 50-60, when progesterone concentrations were found to be higher in Beagles (p < 0.05). Mean progesterone concentrations in pregnant Beagles at days 50-60 after ovulation (day 0) were higher (p < 0.05) than in GSD at that time, but not at earlier time periods. Prolactin concentrations were higher (p < 0.05) in Beagles throughout pregnancy compared with those in the GSD. Mean relaxin concentrations were numerically but not significantly lower in GSD than in Beagles throughout pregnancy. A 10-day oral MPA treatment did not affect progesterone or prolactin secretion in normocyclic non-pregnant Beagles. Medroxyprogesterone acetate serum concentrations were approximately 3.9 ng/ml during treatment and decreased to 0.42 and 0.021 ng/ml within 5 and 15 days after end of treatment, respectively. Intramuscular progesterone supplementation from days 30 to 40 in pregnant Beagles resulted in higher concentrations of progesterone in the 36- to 45-day time periods; prolactin and relaxin concentrations were not significantly affected during or after treatment compared with administration of placebo. The results suggest a tendency towards deficient luteal function in the short-cycle GSD bitches previously studied, which in pregnancy may reflect the observed decreased prolactin concentrations; the possibility that GSD relaxin secretion is deficiency required needs further study. As oral treatment with MPA did not affect progesterone and prolactin release, it may be useful for studying luteal function in pregnant bitches with suspected hypoluteoidism.
    No preview · Article · Jul 2009 · Reproduction in Domestic Animals
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    ABSTRACT: Concentrations of prolactin (PRL), LH, testosterone (T), TSH and thyroxine (T(4)) were determined before and at 20, 120 and 180 min after a single iv injection of thyrotropin-releasing hormone (TRH) in eight Beagles, eight Fox Terriers, six Labrador Retrievers and five Great Danes that were normospermic. Mean basal PRL concentrations were lower in the Fox Terriers compared with the Great Danes (p < 0.05). Mean LH concentrations were higher in the Fox Terriers than in the Beagles, and T was lower in the Fox Terriers at some times but not others (p < 0.05). Thyroid Stimulating Hormone (TSH) concentrations did not differ among breeds, while mean basal T(4) values were lower in Fox Terriers compared with Labrador Retrievers and Great Danes (p < 0.05). Stimulation of T(4) secretion 120 and 180 min after iv TRH injection was most pronounced in the Beagles and less in the Fox Terriers (p < 0.05). The results of the present study indicate that potential breed differences in circulating concentrations of PRL, LH, T, TSH and T(4) in male dogs with apparently normal fertility can be encountered, but further studies are needed to determine whether the observed differences are typical features of these breeds, reflect subsets of dogs within breeds, or are in part because of possible uncontrolled parameters such as sample timing, ambient photoperiod, housing conditions or diet.
    No preview · Article · Jul 2009 · Reproduction in Domestic Animals
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    ABSTRACT: Different abortifacient regimes in dogs were analysed for their effect on the pregnancy corpora lutea (CL), namely, prostaglandin F2a analogue cloprostenol (CLO) combined with dopamine agonist cabergoline (CAB), or progesterone (P4) receptor antagonist aglepristone (AGL). Ovaries were collected after 6-10 days of treatment during first trimester. The CL of the control-group showed strong expression of relaxin (RLX), its receptor RXFP1 and enzymes of steroid biosynthesis (HSD) with high peripheral P4-levels. Whereas RXL, RXFP1 and HSD were lowest expressed in the CLO/CAB-group with a massive degeneration of CL and their blood vessels combined with low peripheral P4-level. The AGL-group showed less extensive CL degeneration and more intensive staining of the examined factors than CLO/CAB. In summary, all examined factors are associated with normal luteal function and are useful tools to stage luteolysis. Although both treatments have the same abortive action, their sequence of events on the CL is different.
    No preview · Article · Jul 2009 · Reproduction in Domestic Animals
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    ABSTRACT: Pharmacologically-induced luteolysis or treatment with an antiprogestin in early post-implantation pregnancy in dogs results in asynchronous death and resorption of conceptuses, indicating variable rates of response of individual conceptuses towards progesterone deficiency. This variability also seems to occur in bitches showing pregnancy failure in response to spontaneous luteal deficiency. In a total of 10 beagle pregnancies (two consecutive pregnancies of five bitches), abortifacient treatments beginning on day 24 after ovulation (ov) involved either administration of a progestin antagonist (total of six pregnancies, in three bitches) or a luteolytic regimen of prostaglandin F(2alpha)-analogue together with a dopamine agonist (total of four pregnancies, in two bitches). The outcomes were evaluated in relation to four control pregnancies in two bitches by assay of serum progesterone, prolactin and relaxin at selected time points or within selected time periods, by ultrasound of conceptuses including measurement of uterine blood flow, and parameters of the blood fibrinolytic system including plasma fibrinogen and plasminogen. The process of embryonic death and conceptus resorption was variable in onset and duration both in bitches that received the progesterone antagonist aglepristone (AGLE) and in those under the luteolytic treatment (cloprostenol combined with cabergoline). Pregnancy termination (death of all embryos or foetuses, respectively) occurred as early as day 29 and as late as day 41 after ov in AGLE-treated bitches, and not earlier than day 37 after ov in luteolytic-treatment bitches. Impending embryonic death was not predicted by changes in relaxin concentration, parameters of the fibrinolytic system, or in the perfusion of small uteroplacental vessels.
    No preview · Article · Jul 2009 · Reproduction in Domestic Animals
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    ABSTRACT: Effects of a short-term hyper- and hypoprolactinaemia on serum concentrations of LH, testosterone and semen quality in six male Beagles were investigated. Blood samples were collected at 3-day intervals for 12 weeks. The time span was divided into five 3-week periods: pre-treatment, metoclopramide (MCP) treatment (0.2 mg/kg orally three times daily), cabergoline (CAB) treatment (5 microg/kg orally once daily), post-treatment 1 and post-treatment 2. In the latter, only semen characteristics were evaluated. Semen parameters were analyzed once per week during the whole 15-week investigation time. At the end of each period, the effects of a single intravenous injection of thyrotropin-releasing hormone (TRH; 10 microg/kg) on the secretion of prolactin (PRL), LH, testosterone, thyroid-stimulating hormone and thyroxine (T4) were investigated. Pre-treatment serum PRL concentration increased under MCP (p < 0.05), followed by a decrease under CAB administration (p < 0.05). Luteinizing hormone and testosterone concentrations were not affected. Except for straight-line sperm velocity, semen quality did not differ between collection periods. A single iv TRH injection induced a significant PRL increase at 20 min in all experimental periods except during CAB treatment. Luteinizing hormone and testosterone did not show clear TRH-related changes. Basic T4 levels were significantly reduced after CAB treatment (p < 0.05). The results of the present study demonstrate that MCP-induced short-term hyperprolactinaemia in male beagles does not seriously affect the hypothalamo-pituitary axis and semen quality.
    No preview · Article · Jul 2009 · Reproduction in Domestic Animals
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    ABSTRACT: The aim of the first part of this study was a comparative immunohistochemical characterisation of the uterine secretory proteins uteroglobin (UG), uterocalin (UC), uteroferrin (UF) and of the calcium-binding protein calbindin (CAL) in the endometrium of clinically acyclic (n = 4) and "cyclic" mules (n = 2) considering clinical-gynaecological findings, endometrial functional morphology and blood serum concentrations of progesterone and estradiol. For this purpose a clinical-gynaecological examination was performed in five animals from April to August and in one mule until November 2004. Endometrial biopsies were taken concurrently (acyclic mules n = 46 biopsies, "cyclic" mules n = 51 biopsies). The endometrial proteins UG, UC, UF and CAL showed a very slight expression in the inactively differentiated endometria of the acyclic mules. In the endometria of the "cyclic" mules the secretion of these proteins was highly variable and no correlation between the phases of the sexual cycle, the concentration of the serum hormone values or the endometrial functional morphology could be detected. In the second part of the study two of the acyclic mules received an oral dose of 0.044 mg/kg BW (body weight) Regumate® for 50 days in order to examine the influence of a long-term progestin administration on the endometrial functional morphology. During the treatment period until 27 days post administration the mules were weekly biopsied and examined both gynaecologically and endocrinologically. Two years after the treatment endometrial biopsies were collected once more. The results obtained prior to Regumate® administration were compared with those during and after the treatment. On that account, 28 endometrial biopsies were examined pathohistologically (H. E. staining) and imunohistologically (UG, UC, UF, CAL, estrogen receptor (ER), progesterone receptor (PR), Ki-67 antigen). Prior to Regumate® medication the endometrium of the acyclic mule mares exhibited an irregular inactive differentiation with a very faint immunolabelling of all uterine proteins investigated. During the medication the endometrium developed a highly irregular secretory differentiation associated with a distinctly increased secretion of CAL, while the secretion of the other investigated proteins remained low. After cessation of the Regumate® administration as well as two years later the endometrium was found to be similarly irregular and inactive as before the treatment, the secretion pattern of the endometrial proteins was comparable to that before medication. In the course of the treatment an overall increased and highly variable expression of the steroid hormone receptors was noted. The administration of Regumate® did not show any significant influence on the endometrial proliferative activity. The results of this study clearly show that in mule mares an exogenous long-term administration of progestins causes an exceedingly pronounced secretory differentiation in the endometrium of acyclic mules, and beyond this generates distinctly visible and in principal reversible morphologic and functional alterations (maldifferentiations) as described in mares.
    No preview · Article · Jan 2008 · Pferdeheilkunde
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    D Förster · A Berk · H. O. Hoppen · W A Rambeck · G Flachowsky
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    ABSTRACT: Rare earth elements (REE) have been used for decades in China to promote growth in plant production and farm animals. Studies are presently also being conducted under Western animal production conditions, however dose-response studies are relatively rare. In this study a total of 80 piglets were fed a diet supplemented with 0, 100, 200, 400 or 800 mg of citrate-bound rare earth elements, consisting of, %: lanthanum 30, cerium 55, praseodymium 5 and neodymium 10. The trial lasted 35 days, the initial mean body weight of the piglets was 7.2 kg. Apart from growth and feeding parameters, blood serum was analysed for T 3 and T 4 by radioimmunoassay (RIA). Feed intake decreased insignifi cantly with higher REE-levels. The daily weight gain of piglets amounted to 283 (control), 301 (100 mg), 254 (200 mg), 258 (400 mg) and 271 g (800 mg). Thyroid hormone levels increased with REE-supplementation. More dose-response studies will be necessary to prove the effects of REE on growth parameters and their intermediate effects.
    Full-text · Article · Jan 2008 · Journal of Animal and Feed Sciences
  • HO Hoppen

    No preview · Article · Oct 2007 · Reproduction in Domestic Animals
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    ABSTRACT: Inhalt: Bei 1 7 klinisch geschlechtsgesunden Beagle-Rüden verschiedener Altersgruppen (1: 7 bis 8 Monate; II: 12 Monate; III: 23 Monate;IV: 3 bis 4 Jahre; V: 8 Jahre) wurden die Körper- und Hodenmaβe sowie die Sekretionsmuster von LH und Testosteron im peripheren Blutplasma bestimmt. Von jedem Ruden wurden im Abstand von 10 bis 14 Tagen zwei Blutprobenserien à 25 Einzelproben über einen Zeitraum von jeweils sechs Stunden unter Einhaltung 15 minütiger Intervalle gewonnen. Die Hodenlange war bei den 7 bis 8 Monate alten Tieren signifikant kleiner (p ≤ 0,01) als bei den älteren Rüden. Die 8 Jahre alten Hunde hatten die gröβten Gonaden. LH und Testosteron zeigten ein ausgeprägt pulsatiles Sekretionsmuster, wobei die LH-Werte zwischen 1,2 und 96 ng/ml und Testosteron zwischen 0,08 und 16 ng/ml varüerten. Die Pulsfrequenz unterschied sich nicht signifikant zwischen den Gruppen und lag im Mittel bei 4,5 Pulsen 16 Stunden. LH-Pulse wurden gewöhnlich von Testosteron-Pulsen gefolgt; der mittlere zeitliche Abstand zwischen beiden Ereignissen betrug 37 ± 15 Minuten.Die Plasmaproben der Gruppe I enthielten die höchsten LH- und die geringsten mittleren Testosteronkonzentrationen (15, 7 ± 13,6 ng/ml bzw. 2,0 ± 1,2 ng/ml). Das höchste durchschnittliche Testosteronniveau (3,6 ± 1,9 ng/ml) war in Gruppe III zu beobachten. Bei den 8 Jahre alten Hunden lag die mittlere LH-Konzentration signifikant unter derjenigen der 7 bis 8 und der 21 bis 23 Monate alten Tiere (p ± 0,01 bzw. p ± 0,05).Contents: Dynamics of LH and testosterone secretion in male beagles of different age In 17 clinically healthy male beagles of five age groups (I: 7 to 8 months, II: 12 months, III: 23 months, IV: 3 to 4 years, V: 8 years) the body size and the testicular dimensions were measured and the concentrations of LH and testosterone were determined in the peripheral blood. Two series of blood samples were collected from each dog with an interval of 10 to 14 days, each series consisting of 25 samples, taken every 15 minutes for 6 hours. The testicular length was significantly smaller (p ± 0.01) in the 7 to 8 months old dogs than in the older animals. The 8 year old dogs had the largest gonads. LH and testosterone secretion showed a marked pulsatility, with LH values ranging from 1.2 to 96 ng/ml and testosterone ranging from 0.08 to 16 ng/ml. Pulse frequency did not differ between groups and averaged 4,5 pulses/6 hours. LH pulses usually preceded testosterone pulses by an average of 37 ± 15 minutes.The samples of group I showed the highest mean LH concentration and the lowest mean testosterone value (15.7 ± 13.6 ng/ml and 2.0 ± 1.2 ng/ml resp.). The highest mean testosterone level (3.6 ± 1.9 ng/ml) was observed in group III. In the 8 year old dogs the mean LH-concentration was significantly lower than that of the animals aged 7 to 8 and 21 to 23 months (p ± 0.01 and p ± 0.05 resp.).
    No preview · Article · Oct 2007 · Reproduction in Domestic Animals
  • M. Lübbecke · E. Klug · H. O. Hoppen · W. Jöchle

    No preview · Article · Oct 2007 · Reproduction in Domestic Animals
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    ABSTRACT: The aim of the present study was to investigate the effects of two medications on two subsequent abortions and plasma hormone concentrations of dogs. For this purpose, two groups of bitches (n=5 each), received the antiprogesterone aglepristone (Alizine) at 10mg/kg body weight on two subsequent days around day 30 after mating. In group II, the antiprolactin cabergoline (Galastop) was additionally administered po at 5 microg/kg body weight until the start of abortion. The plasma concentrations of relaxin, progesterone (P4) and estradiol-17beta (E2) were measured before, during and after each abortion. During the next cycle after the abortion, the same bitches were mated again and in pregnant animals, induction of abortion was performed as before. During the third cycle, pregnant bitches were allowed to whelp. Termination of first pregnancy occurred significantly earlier after the combined treatment (6.8 versus 10.6 days, p<0.05). In both groups and during both abortions, relaxin varied between individuals; however, there was a continuous decrease after the abortions and no significant differences between groups (p>0.05). In one bitch with high relaxin concentrations before treatment (11.6 ng/ml), a cystic endometrial hyperplasia was diagnosed. In the aglepristone only group, P4 concentrations increased significantly after the first application (p<0.05), then decreased continuously until day 45 after the beginning of abortion. In the combined group, there was a continuous decrease until day 45 (p>0.05). At this time, P4 concentrations between 0.47 and 84.9 nmol/l were measured in both groups. The level of E2 over time was not influenced by any medication. We therefore note that the two medications mainly influenced plasma concentrations of P4 in different ways, probably due to specific treatment-hormone interactions. However, all measurements fell within the range considered normal.
    No preview · Article · Oct 2007 · Theriogenology
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    ABSTRACT: Aims: The suitability of using indirect diagnostic procedures (vaginoscopy, vaginal cytology, progesterone analysis) for determination of ovulation in order to predictthe day of parturition and the factors that influence the gestation length were examined. Materials and methods: In 236 bitches the day of ovulation was characterised by semiquantitative or quantitative measurement of progesterone (5-8 ng/ml). Pregnancy was diagnosed the earliest 24 days after ovulation and the number of fetusses was estimated by ultrasonography. Whelping was predicted to occur 62 to 64 days after ovulation. After parturition the breeders were interviewed for the duration of gestation, the number and the sex ratio of puppies. Results: The average gestation length was 62.3±1.5 days. 66.1% of the bitches whelped 62 to 64days after ovulation. On average 6.8±2.6 puppies were born. The number of puppies was negatively correlated with the duration of gestation (p < 0.01) and positively correlated with the size of the bitch (p < 0.001). Gestation length was also influenced by the breed. The time of mating (before or after ovulation) had no effect on the sex ratio of the offspring. Conclusions: Prediction of the day of parturition in relation to ovulation (62 to 64 days after ovulation) is successful in two thirds of the bitches. The variation of gestation from 59 to 70 days is essentially caused by methodical inaccuracies in determination of the time of ovulation, an individual variability of the progesterone concentration at ovulation and the number of puppies. Clinical relevance: In case of sonographic diagnosis of a normal pregnancy the day of parturition should be predicted and documented in relation to the day of ovulation as determined in the preceding oestrus. By this, disorders in later pregnancy (suspected abortion, premature birth, delayed parturition) can be easily and precisely related to gestation stage, thus facilitating the choice of optimum diagnostic and therapeutic procedures in order to avoid loss of puppies and/or fertility.
    No preview · Article · Jan 2007 · Tierärztliche Praxis. Ausgabe K, Kleintiere/Heimtiere

  • No preview · Conference Paper · Aug 2006
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    ABSTRACT: During the six year period between 1996 and 2002, 45 mares underwent unilateral ovariectomy as a result a of diagnosis of ovarian neoplasia, abscess, haematoma or dystrophia. Diagnosis was based on the results of observed behaviour, clinical, ultrasonographical and endocrinological (circulating levels of T, E 2, P 4) examination, and by collection and patho- and immunohistological examination of endometrium biopsy specimens. Typical findings in mares with postoperatively confirmed granulosa cell tumour included stallion-like behaviour, unilateral enlargement of the affected ovary with atrophy of the inhibited contralateral ovary and various abnormalities in the ultrasonographical appearance of the neoplastic ovary. Serum testosterone levels were remarkably elevated in only 19 of the 35 mares with granulosa cell tumor prior to ovariectomy. Surgical procedures included the flank approach by modified grid technique or the ventral midline approach with exteriorisation and complete resection of the affected ovary under general anaesthesia, or laparoscopy in the standing mare. Pathohistological examination of the 45 ovaries revealed 35 granulosa cell tumours, two teratomas, one thecoma, one cystadenoma, one ovarian abscess, one ovarian haematoma, one corpus luteum cyst, one stromal metaplasia and one stromal thecosis. With only two exceptions, even those granulosa cell tumours which remained clinically and endocrinologically unclear were associated with an endometrial maldifferentiation (EMD), possibly indicating a hormonal activity of the tumour cells. Endometrial maldifferentiation may indicate hormonal disturbances. It also serves as a distinct bio-assay which is available prior to surgery. In addition to clinical, ultrasonographic and endocrinological findings, endometrial biopsy is a useful aid in the evaluation of abnormal ovaries. Follow-up results for 32 mares regarding reestablishment of fertility and cessation of irregular behaviour were judged to be good, particularly following resection of a granulosa cell tumour. All those mares developed normal behaviour postoperatively and 13 of the 14 mares that were mated or inseminated conceived and reached parturition.
    No preview · Article · Nov 2003 · Pferdeheilkunde

  • No preview · Article · Aug 2002 · Theriogenology
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    ABSTRACT: In the present study the concentration of relaxin in peripheral blood plasma was assessed during canine pregnancy for its suitability as a pregnancy indicator, using a newly developed relaxin enzyme immunoassay. A significant relaxin increase was found in pregnancy at day 24 after ovulation. However, this relaxin increase did not correlate either with litter size or with body weight of the bitch. Induction of abortion with prostaglandin F2 alpha resulted in reduced peripheral relaxin levels, suggesting a damage of the placenta due to this medical intervention. Thus, the results confirm that relaxin, which is produced by the placenta, is a useful marker for early pregnancy diagnosis in the bitch. Relaxin measurement is recommended for detection of pregnancy either alone, or as supplement of ultrasonographic findings.
    No preview · Article · Feb 2002 · DTW. Deutsche tierärztliche Wochenschrift
  • C.P. Bartmann · H.-A. Schoon · H.O. Hoppen
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    ABSTRACT: During a four year period (1996-1999), 31 mares underwent an unilateral ovariectomy as a result of the diagnosis of ovarian neoplasia. The diagnosis was based on the results of behavioural control, clinical, ultrasonographical and endocrinological (circulating levels of T, E 2, P 4) examination added by collection and patho- and immunohistological examination of endometrium biopsy specimens. Typical findings in mares with postoperatively confirmed granulosa cell tumour included stallion like behaviour, unilateral enlargement of the affected ovary with atrophy of the inhibited contralateral ovary and abnormality in different variations in the ultrasonographical appearance of the neoplastic ovary. Prior to ovariectomy serum testosterone levels were remarkably elevated in 13 of the 31 mares. Surgical procedures included flank approach by modified grid technique or ventral midline approach with exteriorization and complete resection of the affected ovary under general anesthesia. Pathohistological examination of the 31 ovaries revealed 28 granulosa cell tumours, one thecoma, one cystadenoma and one malignan teratoma. With only one exception, even clinically and endocrinologically unclear remaining granulosa cell tumours were associated with an irregular endometrial differentiation (IED) possibly indicating a hormonal activity of the tumour cells. The teratoma and the cystadenoma did not affect the endometrial differentiation. Irregular endometrial differentiation may indicate hormonal disturbances due to ovarian neoplasia and serves as a distinct bio assay which is available prior to surgery. In addition to clinical, ultrasonographical and endocrinological findings, endometrial biopsy is a useful aid in the evaluation of abnormal ovaries.
    No preview · Article · Mar 2001 · Pferdeheilkunde
  • B. Klauß-Perschke · H.-O. Hoppen · S. Schlote

    No preview · Article · Mar 2001 · Pferdeheilkunde
  • K Lange · E K Cordes · H O Hoppen · A R Günzel-Apel
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    ABSTRACT: The concentrations of testosterone, 5 alpha-dihydrotestosterone, oestradiol and oestrone were determined in peripheral blood plasma and semen of male dogs. In an experimental study, three Beagles were treated once with delmadinone acetate (1 mg kg-1 body weight, i.m.) and three were submitted to oral applications of finasteride (1 mg kg-1 body weight) once a day for 3 weeks. In a clinical study, 51 dogs of different breeds were divided into four groups according to the total number of spermatozoa in ejaculates (normospermia, slight oligozoospermia, severe oligozoospermia and azoospermia). The testosterone concentrations were significantly lower in sperm-rich ejaculate fractions and prostatic secretions compared with blood plasma (P < 0.05). The lowest concentration of testosterone was found in prostatic fluid. Concentrations of 5 alpha-dihydrotestosterone were similar in blood plasma and sperm-rich fractions, and significantly lower in prostatic secretions (P < 0.05). The concentrations of oestradiol and oestrone did not differ between blood plasma and either ejaculate fraction. Significantly higher 5 alpha-dihydrotestosterone concentrations and significantly lower concentrations of oestradiol and oestrone were found in prostatic secretions from azoospermic ejaculates compared with prostatic secretions of normospermic and oligozoospermic ejaculates. Delmadinone acetate and finasteride caused reversible suppression of the secretory activity of the prostate gland. The application of delmadinone acetate led to a temporary alteration of maturation of epididymal spermatozoa.
    No preview · Article · Jan 2001 · Journal of reproduction and fertility. Supplement

Publication Stats

467 Citations
48.73 Total Impact Points

Institutions

  • 1991-2009
    • University of Veterinary Medicine Hannover
      • Institute of Food Toxicology and Chemical Analysis
      Hanover, Lower Saxony, Germany
  • 1993-2007
    • Hochschule Hannover
      Hanover, Lower Saxony, Germany
    • University of Saskatchewan
      Saskatoon, Saskatchewan, Canada
  • 2001-2003
    • University of Leipzig
      • Institute of Pathology
      Leipzig, Saxony, Germany
  • 1999-2000
    • University of Veterinary Medicine in Vienna
      Wien, Vienna, Austria