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1.
Reprod Domest Anim ; 52(1): 140-143, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27864846

RESUMO

CASE REPORT: A 6.5-year-old clinically healthy German Shepherd Dog with regular oestrous cycles of 6 months was presented for pregnancy diagnosis on day 38 after ovulation (p.ov.). Ultrasonography revealed three individual placental sites in progressed resorption and two vital adequately developed foetuses sharing a joint placenta. On days 41 and 48 p.ov., sonographic signs indicated normal development of both foetuses, but on day 52 p.ov., both foetuses were found to be dead. A caesarean section was performed the same day. Examination of the removed uterus confirmed the diagnosis of a "twin" pregnancy with two foetuses sharing the same placental site but separate amniotic membranes. One foetus showed generalized oedema (anasarca). Bacterial culture of swabs taken from inside the placental cavity was negative. At histological examination of the uterus, no signs of inflammation were found. Serum relaxin concentrations (day 38, 41, 48 and 52. p.ov.) were consistent with those of bitches with normal pregnancies. Cytogenetic analysis of the two foetuses revealed dizygotic twins, one male and one female according to SRY-PCR. By genotyping 17 high-polymorphic canine microsatellites, it could be demonstrated that the two foetuses developed from two different oocytes.


Assuntos
Aborto Animal/diagnóstico por imagem , Placenta/diagnóstico por imagem , Prenhez , Gêmeos Dizigóticos/genética , Animais , Córion , Cães , Feminino , Genótipo , Masculino , Gravidez , Relaxina/sangue , Ultrassonografia Pré-Natal/veterinária
2.
Reprod Domest Anim ; 49(1): 145-57, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24428565

RESUMO

The objective was to assess the effect of a short-term scrotal hyperthermia in dogs on quantitative and qualitative ejaculate parameters, testicular blood flow and testicular and epididymal histology. After a control period, the scrotum of seven normospermic adult beagle dogs was insulated with a self-made suspensory for 48 h. Nine weeks later, two animals were castrated, while in five animals, scrotal hyperthermia was repeated. Dogs were castrated either 10 or 40 days thereafter. In each phase of scrotal insulation, average scrotal surface temperature increased by 3.0°C. Semen was collected twice weekly throughout the experiment. Total sperm count did not change after the first hyperthermia, but it slightly decreased after the second (p < 0.05). Profiles of sperm morphology and velocity parameters (CASA) rather indicated subtle physiological variations in sperm quality than effects of a local heat stress. Chromatin stability of ejaculated spermatozoa as indicated by SCSA remained constant throughout the experiment. Perfusion characteristics of the gonads, that is, systolic peak velocity, pulsatility and resistance index at the marginal location of the testicular artery, did not change due to hyperthermia (p > 0.05). Histological examination of excised testes and epididymides for apoptotic (TUNEL and activated caspase-3) and proliferating cells (Ki-67 antigen) indicated only marginal effects of scrotal insulation on tissue morphology. In conclusion, a mild short-term scrotal hyperthermia in dogs does not cause substantial changes in sperm quantity and quality. In contrast to other species, canine testes and epididymides may have a higher competence to compensate such thermal stress.


Assuntos
Temperatura Corporal/fisiologia , Cães/fisiologia , Temperatura Alta , Escroto/fisiologia , Espermatozoides/fisiologia , Testículo/irrigação sanguínea , Acrossomo/ultraestrutura , Animais , Apoptose , Proliferação de Células , Cromatina/ultraestrutura , Epididimo/citologia , Masculino , Orquiectomia/veterinária , Fluxo Sanguíneo Regional , Análise do Sêmen/veterinária , Contagem de Espermatozoides , Espermatozoides/ultraestrutura , Testículo/citologia , Testículo/diagnóstico por imagem , Ultrassonografia
3.
Theriogenology ; 71(5): 746-53, 2009 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-18996577

RESUMO

The effects of gonadectomy on the secretion of prolactin, LH, TSH, and thyroxine were investigated. Blood serum hormone concentrations were analysed before and at 20, 120, and 180min after a single iv TRH injection in each of eight healthy intact and castrated male beagle dogs before (control) and after 4-week treatment with the dopamine-2 receptor agonist cabergoline. Under control conditions the mean prolactin, TSH, and thyroxine concentrations were similar in intact and gonadectomised dogs, and administration of TRH provoked a significant (p<0.01) increase in concentrations of the three hormones. The overall inhibitory effect of cabergoline treatment on prolactin secretion was more pronounced in the castrated dogs compared with the intact group. Cabergoline significantly suppressed the TRH-induced prolactin increase in each group (p<0.01). Corresponding TRH-stimulated TSH concentrations were not affected by cabergoline. In the gonadectomised dogs, thyroxine concentrations before and at 120 and 180min after TRH injection were significantly lower than under control conditions. LH concentrations were always higher (p<0.01) in gonadectomised dogs compared with the intact dogs, but appeared to be affected neither by TRH nor by cabergoline administration. It can thus be concluded from the results, that gonadectomy does not result in hyperprolactinaemia in male dogs, while LH concentrations are significantly increased due to missing androgen feedback. Thyroid function remains unaffected by gonadectomy. Testicular steroids appear to interact with central dopaminergic and probably other neuroendocrine mechanisms regulating the secretion of prolactin, TSH, and thyroxine. Thus, long-term dopamine-2 receptor agonistic treatment may lead to a hypothyroid condition in castrated male dogs.


Assuntos
Cães/fisiologia , Hormônio Luteinizante/sangue , Orquiectomia/veterinária , Hipófise/fisiologia , Prolactina/sangue , Glândula Tireoide/fisiologia , Animais , Cabergolina , Agonistas de Dopamina/administração & dosagem , Ergolinas/administração & dosagem , Cinética , Masculino , Testículo/fisiologia , Glândula Tireoide/efeitos dos fármacos , Tireotropina/sangue , Hormônio Liberador de Tireotropina , Tiroxina/sangue
4.
Reprod Domest Anim ; 44 Suppl 2: 59-64, 2009 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-19754537

RESUMO

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.


Assuntos
Cães/genética , Fase Luteal/fisiologia , Prenhez , Progesterona/sangue , Prolactina/sangue , Relaxina/sangue , Animais , Anticoncepcionais Femininos/farmacologia , Cães/fisiologia , Feminino , Fase Luteal/sangue , Fase Luteal/genética , Acetato de Medroxiprogesterona/farmacologia , Gravidez , Prenhez/genética , Fatores de Tempo
5.
Reprod Domest Anim ; 44 Suppl 2: 185-9, 2009 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-19754564

RESUMO

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.


Assuntos
Abortivos/farmacologia , Aborto Induzido/veterinária , Aborto Animal/induzido quimicamente , Corpo Lúteo/anatomia & histologia , Cães , Animais , Feminino , Gravidez , Progesterona/sangue , Relaxina/sangue
6.
Reprod Domest Anim ; 44 Suppl 2: 320-5, 2009 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-19754595

RESUMO

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.


Assuntos
Hipófise/efeitos dos fármacos , Prolactina/sangue , Sêmen/efeitos dos fármacos , Testículo/efeitos dos fármacos , Glândula Tireoide/efeitos dos fármacos , Animais , Cabergolina , Cães , Agonistas de Dopamina/farmacologia , Antagonistas de Dopamina/farmacologia , Ergolinas/farmacologia , Hormônio Luteinizante/sangue , Masculino , Metoclopramida/farmacologia , Testosterona/sangue , Tireotropina/sangue , Hormônio Liberador de Tireotropina/administração & dosagem , Hormônio Liberador de Tireotropina/farmacologia , Tiroxina/sangue
7.
Reprod Domest Anim ; 44 Suppl 2: 174-81, 2009 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-19754562

RESUMO

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.


Assuntos
Prenhez , Progesterona/sangue , Aborto Induzido/veterinária , Aborto Animal , Animais , Cabergolina , Cloprostenol/administração & dosagem , Cloprostenol/farmacologia , Cães , Desenvolvimento Embrionário , Ergolinas/administração & dosagem , Ergolinas/farmacologia , Estrenos/administração & dosagem , Estrenos/farmacologia , Feminino , Gravidez , Prolactina/sangue , Relaxina/sangue
8.
Reprod Domest Anim ; 44 Suppl 2: 279-82, 2009 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-19754586

RESUMO

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.


Assuntos
Cães/sangue , Hormônio Luteinizante/sangue , Prolactina/sangue , Testosterona/sangue , Tireotropina/sangue , Tiroxina/sangue , Animais , Cães/genética , Cães/fisiologia , Masculino , Espermatogênese/fisiologia
9.
Theriogenology ; 114: 14-24, 2018 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-29574305

RESUMO

Proliferation and apoptosis play an important role in cyclic changes in the healthy canine endometrium. Proteins of the Bcl-2-family are known to be involved in the regulation of apoptosis. However, only few reports mention their expression patterns during cystic endometrial hyperplasia (CEH). In order to correlate proliferative and apoptotic processes, expression of the apoptosis-regulatory proteins Bcl-2 (anti-apoptotic) and Bax (pro-apoptotic) in healthy and cystic hyperplastic endometrial tissue as well as in pyometra was investigated. Uteri from 33 bitches were assigned to three groups: group 1 - healthy endometrium (n = 12), group 2 - CEH (n = 17) and group 3 - pyometra (n = 4). Markers for proliferation (Ki-67) and apoptosis (activated caspase-3 and TUNEL-method) as well as expression of Bcl-2 and Bax were determined in all endometrial layers. For groups 1 and 2 this was done during endometrial gland secretion in mid and late luteal phase (mLP, lLP), endometrial reparation in early anestrus (eAE) and in the regenerated endometrium in late anestrus (lAE). For group 3 only the late luteal phase was investigated. In group 1, cyclic proliferation patterns were found predominantly in superficial glands (SG) and stroma, whereas progesterone-mediated low expression levels coincided with high apoptosis rates in the basal glands (BG). In eAE, higher apoptotic activity was detected compared to lLP and lAE. Bcl-2 and Bax expression levels showed an inverse cyclic relationship in all tissue layers. In the stroma, in eAE, a rise in proliferative activity and concomitant increase in anti-apoptotic Bcl-2 expression levels was found, indicating that this layer serves as a source for endometrial regeneration. In CEH, no or limited cyclic patterns of proliferation, apoptosis, Bcl-2 and Bax were found. Increased proliferation rates coincided with deregulated apoptosis. Besides the glandular compartments, the stroma played an important role in the pathogenesis of canine CEH. In case of pyometra, both proliferation and apoptosis increased, indicating irreversible damage of the inflamed canine endometrium. In conclusion Bcl-2 and Bax play a role both in the physiological regenerative processes of the cyclic canine endometrium and in deregulating proliferation and apoptosis in CEH and pyometra.


Assuntos
Apoptose , Proliferação de Células , Doenças do Cão/patologia , Hiperplasia Endometrial/veterinária , Endométrio/citologia , Animais , Cães , Hiperplasia Endometrial/patologia , Endométrio/patologia , Feminino , Regulação da Expressão Gênica , Humanos , Proteínas Proto-Oncogênicas c-bcl-2/genética , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Proteína X Associada a bcl-2/genética , Proteína X Associada a bcl-2/metabolismo
10.
Theriogenology ; 66(6-7): 1797-802, 2006 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-16472849

RESUMO

A current priority for the preservation of the endangered Mexican gray wolf (Canis lupus baileyi) is the development of a sperm-based genome resource bank for subsequent use in artificial insemination. To optimize the quality of cryopreserved sperm, the procedures involved in processing semen before and during freezing need to be improved. The aim of this study were to examine the effects of: (i) different cooling periods before freezing and (ii) addition of Equex pasta (Minitüb, Tübingen, Germany) on the characteristics of sperm from the generic gray wolf and the Mexican gray wolf after cooling and cryopreservation. For Mexican wolf sperm, cooling for 0.5 and 1.0 h had a less detrimental effect on cell morphology than cooling for 2.5 h, whereas the slower cooling rate (2.5 h) had a less detrimental effect on functional parameters and seemed to cause less damage to plasma membrane and acrosome integrity than 0.5 and 1.0 h. For the generic gray wolf, cooling semen for 2.5 h had less detrimental effect on plasma membrane integrity and viability; together with the 0.5 h cooling time, it yielded the highest percentages of intact acrosomes. As previously shown in the domestic dog, Equex pasta had no beneficial effect on sperm characteristics in either wolf species.


Assuntos
Criopreservação/veterinária , Crioprotetores , Preservação do Sêmen/veterinária , Espermatozoides , Lobos/fisiologia , Acrossomo/fisiologia , Animais , Membrana Celular/fisiologia , Conservação dos Recursos Naturais , Criopreservação/métodos , Masculino , Preservação do Sêmen/métodos , Dodecilsulfato de Sódio , Motilidade dos Espermatozoides/fisiologia
11.
Theriogenology ; 65(8): 1666-77, 2006 May.
Artigo em Inglês | MEDLINE | ID: mdl-16289263

RESUMO

In the present study, the pulsatile serum profiles of prolactin, LH and testosterone were investigated in eight clinically healthy fertile male beagles of one to six years of age. Serum hormone concentrations were determined in blood samples collected at 15 min intervals over a period of 6 h before (control) and six days before the end of a four weeks treatment with the dopamine agonist cabergoline (5 microg kg(-1) bodyweight/day). In addition, the effect of cabergoline administration was investigated on thyrotropin-releasing hormone (TRH)-induced changes in the serum concentrations of these hormones. In all eight dogs, the serum prolactin concentrations (mean 3.0 +/- 0.3 ng ml(-1)) were on a relatively constant level not showing any pulsatility, while the secretion patterns of LH and testosterone were characterised by several hormone pulses. Cabergoline administration caused a minor but significant reduction of the mean prolactin concentration (2.9 +/- 0.2 ng ml(-1), p < 0.05) and did not affect the secretion of LH (mean 4.6 +/- 1.3 ng ml(-1) versus 4.4 +/- 1.7 ng ml(-1)) or testosterone (2.5 +/- 0.9 ng ml(-1) versus 2.4 +/- 1.2 ng ml(-1)). Under control conditions, a significant prolactin release was induced by intravenous TRH administration (before TRH: 3.8 +/- 0.9 ng ml(-1), 20 min after TRH: 9.1 +/- 5.9 ng ml(-1)) demonstrating the role of TRH as potent prolactin releasing factor. This prolactin increase was almost completely suppressed under cabergoline medication (before TRH: 3.0 +/- 0.2 ng ml(-1), 20 min after TRH: 3.3 +/- 0.5 ng ml(-1)). The concentrations of LH and testosterone were not affected by TRH administration. The results of these studies suggest that dopamine agonists mainly affect suprabasal secretion of prolactin in the dog.


Assuntos
Cães/metabolismo , Agonistas de Dopamina/farmacologia , Ergolinas/farmacologia , Hormônio Luteinizante/metabolismo , Prolactina/metabolismo , Testosterona/metabolismo , Administração Oral , Animais , Área Sob a Curva , Cabergolina , Hormônio Luteinizante/sangue , Masculino , Prolactina/sangue , Testosterona/sangue , Hormônio Liberador de Tireotropina/sangue , Hormônio Liberador de Tireotropina/efeitos dos fármacos , Hormônio Liberador de Tireotropina/farmacologia
12.
Theriogenology ; 66(6-7): 1431-5, 2006 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-16499960

RESUMO

Twenty-two nonpregnant and 19 pregnant German Shepherd dogs were assigned to either a control group or a suspected short-cycling group, based on the interestrous interval (> or = 6 month and < 5 month, respectively) and data from previous pregnancies. Blood serum concentrations of progesterone and prolactin were determined from days 5 to 60 (day 0 = ovulation) for characterization of luteal function. In pregnant bitches, placental integrity was additionally assessed by relaxin concentrations. The nonpregnant, suspected short-cycling bitches had significantly lower progesterone concentrations than the controls, indicating decreased luteal activity both in the autonomous and prolactin-dependent period. In the pregnant suspected short-cycling bitches, unavoidable progesterone supplementation prevented assessment of luteal function; it may have suppressed prolactin secretion (significantly lower prolactin concentrations from days 20 to 60, compared with the pregnant control group), but deficient prolactin secretion affecting luteal function cannot be excluded. The significantly lower relaxin concentrations, together with a high incidence of embryonic death found in the pregnant, suspected short-cycling group, may indicate loss of placental integrity and may have caused decreased prolactin concentrations.


Assuntos
Cães/sangue , Fase Luteal/sangue , Prenhez/sangue , Progesterona/sangue , Prolactina/sangue , Relaxina/sangue , Animais , Cães/fisiologia , Feminino , Tamanho da Ninhada de Vivíparos , Gravidez , Ultrassonografia Pré-Natal/veterinária
13.
Theriogenology ; 66(6-7): 1709-14, 2006 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-16481034

RESUMO

Although spontaneous and medically induced canine embryonic or fetal death and "resorption" are clinically well documented, morphological studies of these processes are still missing. The objective of this study was therefore a detailed morphological investigation of canine placental sites after embryonic or fetal death. In five pregnant beagle bitches, embryonic or fetal death was induced by cloprostenol and cabergoline or by aglepristone. Two dogs served as untreated controls. Between Days 30 and 33 of gestation, the bitches were ovariohysterectomized, placental sites were fixed and examined by different methods. Morphological features of placental sites after both treatments were similar, finally leading to a complete disappearance of the placental labyrinth. Although there was an increase in the number of cells in the glandular chambers (superficial endometrial glands) expressing lysozyme after induced fetal death, signs of phagocytosis were absent in these cells, and no increased infiltration of maternal stroma by macrophages (compared to normal placental sites at the same time of gestation) occurred. We inferred that fetal and placental tissues were lysed, but no phagocytosis by genuine or "functional" macrophages was detectable. Further investigations are needed for a more detailed understanding of the morphological processes occurring after embryonic or fetal death in the dog.


Assuntos
Cães/fisiologia , Perda do Embrião/patologia , Perda do Embrião/veterinária , Morte Fetal/patologia , Morte Fetal/veterinária , Placenta/ultraestrutura , Animais , Cabergolina , Cloprostenol , Perda do Embrião/induzido quimicamente , Ergolinas , Estrenos , Feminino , Morte Fetal/induzido quimicamente , Imuno-Histoquímica/veterinária , Microscopia Eletrônica de Transmissão/veterinária , Gravidez
14.
Theriogenology ; 63(5): 1390-406, 2005 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-15725446

RESUMO

In the past years a series of functional assays has been developed to determine the structural, morphological and functional integrity of the plasma membrane and sperm acrosomal membrane. Cell volume regulation is an important physiological function crucial for the success of cryopreservation. In this study, the effects induced by freezing-thawing were judged by evaluating the functional characteristics of frozen-thawed semen samples submitted to secondary stress such as osmotic challenge or incubation under capacitating conditions, following cryopreservation. Prior to freezing, dog semen samples were diluted in the presence or absence of Equex STM Paste, which contains sodium dodecyl sulphate (SDS) as the active ingredient. Cell volume regulation and capacitation and calcium ionophore-induced membrane dynamics were assessed in freshly diluted and frozen-thawed semen samples by electronic volume measurement and flow cytometry. Cryopreservation led to a disturbance of the volume regulatory function and to a rapid decrease in the proportion of acrosome-reacted live spermaotozoa. Extender containing Equex STM Paste had a protective effect on isotonic cell volume, on regulatory function under hypertonic conditions, and on the proportion of live acrosome-reacted cells. The evaluation of the functional state of sperm submitted to secondary stress after freezing-thawing leads to a more subtle characterization of sperm function and helps improve the cryoprotective efficiency of the extender.


Assuntos
Membrana Celular/fisiologia , Criopreservação/veterinária , Crioprotetores , Cães , Preservação do Sêmen/veterinária , Espermatozoides/ultraestrutura , Acrossomo/fisiologia , Acrossomo/ultraestrutura , Reação Acrossômica , Animais , Membrana Celular/ultraestrutura , Tamanho Celular , Criopreservação/métodos , Ionóforos/farmacologia , Masculino , Preservação do Sêmen/métodos , Capacitação Espermática , Motilidade dos Espermatozoides
15.
Theriogenology ; 41(3): 737-45, 1994 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-16727428

RESUMO

Baseline concentrations of LH and testosterone (T) in blood, their pulses, and LH and T response to GnRH (5 microg/kg) treatment were compared in 19 sexually sound male beagles and in 2 sexually dysfunctional dogs. The intact beagles were allocated to 4 groups according to age, which ranged from pubertal 7-mo-old animals to 11-yr-old adults. Baseline concentrations of LH and T were measured every 15 min for a period of 6 h and for a further 3 h following challenge with GnRH. Both LH and T were released in a pulsatile fashion with a wide range of pulse frequency and amplitude. The time intervals between the LH and T pulses ranged from 30 to 60 min, with no significant difference between groups. However, LH concentrations were significantly higher (P<0.01) and T values were markedly lower in the 7-mo-old pubertal dogs than in the other age groups. Following GnRH administration, LH peaked within 15 to 30 min in all the animals, with a significantly higher increase occurring in the pubertal group (P<0.05). Peak T values occurred 15 to 105 min after the LH peaks, with no clear increases occurring in the pubertal dogs. In the 2 sexually dysfunctional animals, LH levels increased following GnRH treatment; however, T values remained extremely low both before and after treatment, indicating loss of Leydig cell function.

16.
Theriogenology ; 61(1): 35-54, 2004 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-14643860

RESUMO

Response to osmotic shock is an important aspect of mammalian sperm physiology. In this study we recorded volume changes of dog spermatozoa at 39, 33, and 25 degrees C under isotonic conditions and following hypotonic shock. Cell volume measurements were performed electronically in saline solutions of 300 and 150 mOsmol kg(-1), and Percoll-washed preparations were compared with unwashed samples. The involvement of potassium channels in volume control was tested by treatment with quinine, while the involvement of the plasma membrane Na(+)-K+ pump was tested by treatment with ouabain. The role of the cytoskeleton was investigated by treatment with colchicine and cytochalasin D. The number of cell populations observed varied with temperature and tonicity. In both types of sperm preparations, between two and three populations were present under isotonic conditions at 25 degrees C whereas at 39 and 33 degrees C only one population was detected. Hypotonic stress at the higher temperatures caused the single population to swell, whereas at 25 degrees C it resulted in a population of cells whose modal volume was similar to that of the middle isotonic sub-population. Both quinine and the cytoskeletal inhibitors markedly increased swelling both under hypotonic conditions at 39 degrees C and under isotonic conditions at 25 degrees C. However, little or no effect of ouabain was observed. We conclude that in dog spermatozoa swelling in response to hypotonic conditions is minimised through the activity of potassium channels and the presence of an intact cytoskeletal network. Under isotonic conditions at 25 degrees C, a considerable proportion of the sperm population is already swollen; this swelling varies between individual males and appears to be due to lowered cytoskeletal and potassium channel activity.


Assuntos
Tamanho Celular , Citoesqueleto/fisiologia , Cães , Canais de Potássio/fisiologia , ATPase Trocadora de Sódio-Potássio/fisiologia , Espermatozoides/citologia , Animais , Colchicina/farmacologia , Citocalasina D/farmacologia , Citoesqueleto/efeitos dos fármacos , Soluções Hipotônicas , Masculino , Pressão Osmótica , Ouabaína/farmacologia , Bloqueadores dos Canais de Potássio/farmacologia , Quinina/farmacologia , ATPase Trocadora de Sódio-Potássio/antagonistas & inibidores , Temperatura
17.
Theriogenology ; 61(9): 1617-34, 2004 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-15019459

RESUMO

Essential steps of the capacitation process take place in the oviductal isthmus. A crucial step in the process of capacitation is the phosphorylation of membrane proteins. The aims of this work were (1) to study the effect of dog sperm binding to oviductal epithelium on tyrosine phosphorylation and (2) to investigate the specificity of regulation of molecular changes by the oviduct of different species by comparing the numbers of canine sperm bound to heterologous (porcine) and homologous epithelium, and the kinetics of tyrosine phosphorylation. Semen was collected from four healthy dogs and washed through a Percoll gradient. Explants, small pieces of epithelium, were cut from porcine and estrous bitch oviducts. During 6 h of coincubation in Tyrode medium, the numbers of bound sperm were counted by microvideographic observation, and the state of tyrosine phosphorylation was determined immunocytochemically after 3, 30, 90, 180 and 360 min. Canine sperm bound in similar numbers to homologous and heterologous explants. Increasing tyrosine phosphorylation of tail proteins and subsequent phosphorylation of sperm head proteins were observed. Binding occurred mainly in sperm with non-phosphorylated heads (approximately 2% phosphorylated), while higher proportions of head-phosphorylated cells were found in unbound populations (approximately 40-60%;P<0.05). The head phosphorylation progressed significantly during incubation in unbound spermatozoa (P<0.05), while it was suppressed in bound suspensions. The rate of tyrosine phosphorylation of sperm tail proteins was higher in cells bound to explants than in unbound cells or in those incubated in control medium. There were no significant differences with respect to the kinetics of tyrosine phosphorylation between the two coincubation systems. These observations support the hypothesis that spermatozoa with non-phosphorylated heads preferentially attach to epithelial cells. Tyrosine phosphorylation of sperm head proteins and capacitation are delayed in spermatozoa in close contact with oviductal epithelium. This mechanism appears to be species-independent, as sperm bound similarly to pig and dog oviduct explants, and similar phosphorylation kinetics were observed in both types of tissue.


Assuntos
Tubas Uterinas/fisiologia , Espermatozoides/metabolismo , Tirosina/metabolismo , Animais , Cães , Feminino , Cinética , Masculino , Fosforilação , Proteínas/metabolismo , Especificidade da Espécie , Capacitação Espermática , Cabeça do Espermatozoide/química , Cauda do Espermatozoide/química , Espermatozoides/química , Suínos
18.
Artigo em Alemão | MEDLINE | ID: mdl-9710936

RESUMO

Continuous sonographic examinations of the physiological ovarian structures were performed in four anovulatory and 14 pseudopregnant cycles. The animals were examined in standing position from the right and left flank using a mechanical 13 MHz sector scanner with integrated stand off pad. The intervals were two or three days during anoestrous and luteal phases and one day during follicular phases. The follicles could be identified from a minimum size of 1.0 mm and reached maximum mean diameters of 3.3 mm within at most eight days. The period of follicular regression was eight days in the anovulatory cycles. In the pseudopregnant cycles ovulation could be sonographically verified by the disappearance of follicles of 3 or more mm in diameter within 24 hours. Immediately thereafter the ovary had a more or less homogeneous appearance. Luteal development gave different sonographic findings. In general anechoic structures of 1 mm in diameter were recognizable within three days after ovulation, coming up to 5.3 mm within five days. Compact corpora lutea were easily identified as nearly homogeneous structures, that bulged over the ovarian surface. Corpora lutea, that were embedded in the ovary could not be detected without doubt.


Assuntos
Anovulação/veterinária , Doenças do Gato/diagnóstico por imagem , Ovário/diagnóstico por imagem , Pseudogravidez/veterinária , Anestro/fisiologia , Animais , Anovulação/diagnóstico por imagem , Anovulação/fisiopatologia , Doenças do Gato/fisiopatologia , Gatos , Corpo Lúteo/diagnóstico por imagem , Corpo Lúteo/fisiologia , Feminino , Fase Folicular/fisiologia , Fase Luteal/fisiologia , Folículo Ovariano/diagnóstico por imagem , Folículo Ovariano/fisiologia , Ovário/fisiologia , Ovulação/fisiologia , Pseudogravidez/diagnóstico por imagem , Pseudogravidez/fisiopatologia , Ultrassonografia
19.
Dtsch Tierarztl Wochenschr ; 105(3): 95-8, 1998 Mar.
Artigo em Alemão | MEDLINE | ID: mdl-9581375

RESUMO

The castration of dogs and cats is regulated in section 6 of the German Law for Prevention of Cruelty To Animals (Tierschutzgesetz) dated February 17, 1993. Gonadectomy in juvenile and prepuberal as well as in adult vertebrates is only permitted by law in case of a medical indication or a special using of the animal. On account of his special knowledge, the veterinarian is made responsible by law for the estimation of the indispensibility and for the performance of castration. As early-age castration means usually the surgical removal of healthy gonads from a healthy organism, it is principally forbidden by law at present. The bill of June 30, 1995 points to the legitimation of castration for contraception. This does, however, not dispense the veterinarian from deciding in each individual case under consideration of unwanted side effects and consequences that can be caused by castration and early-age castration, respectively.


Assuntos
Bem-Estar do Animal , Orquiectomia , Ovariectomia , Animais , Gatos , Cães , Feminino , Masculino , Maturidade Sexual
20.
Dtsch Tierarztl Wochenschr ; 107(11): 438-43, 2000 Nov.
Artigo em Alemão | MEDLINE | ID: mdl-11153229

RESUMO

Reference values were determined for blood plasma concentrations of albumin, total protein, glucose, total bilirubin, urea, creatinine, cholesterin, triglycerides, total calcium und anorganic phosphate as well as the activities of alkaline phosphatase, alanine-amino-transferase (ALT) and glutamate-dehydrogenase based on 109-124 healthy puppies at different times (1st-3rd, 8th-10th, 28th-33rd, and 50th-58th day of life). In addition, all the results were calculated separately for the breeds involved in this study (Beagle [n = 34-40], German Shepherd [n = 32-35] and Golden Retriever [n = 43-53]). Furthermore, male and female puppies were compared. All examined parameters showed remarkable dynamics during the suckling period. Often the values exceeded respectively fell below the reference ranges for adult dogs. Significant systematic breed influences as for instance a significantly lower glucose concentration for the German Shepherd puppies were also found for other parameters, especially for alkaline phosphatase and ALT. However, differences between male and female animals were only present sporadically and were of minor clinical relevance. The gathered breed differences show that it is worthwhile not only to acquire age specific reference ranges but also breed specific reference ranges for selected parameters. On the other hand, reference ranges without the definition of the breed can only be used for orientation.


Assuntos
Análise Química do Sangue/veterinária , Cães/sangue , Envelhecimento , Animais , Animais Recém-Nascidos , Proteínas Sanguíneas/análise , Enzimas/sangue , Lipídeos/sangue , Valores de Referência , Especificidade da Espécie
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