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31.
IP Santos CLFG Ramos JLG Ramos RF Oliveira ICN Cunha 《Reproduction in domestic animals》2013,48(1):160-164
Electroejaculation is a technique that can be used to collect semen from canines, but its use with this group of animals is restricted by low success rate and low semen quality. Here, we evaluated whether pharmacological and sexual sensory stimuli, which may affect ejaculation, can increase electroejaculation efficiency and improve ejaculate quality. We worked with 20 dogs of mixed breed weighing between 5.3 and 22.2 kg, divided into two groups. Both groups were exposed to a spayed female for 10 min, but in the second group, the same spayed female had her vagina impregnated with methyl 4‐hydroxybenzoate synthetic pheromone for 10 min and after receiving dinoprost tromethamine IM, 0.1 mg /kg. After stimulation, all dogs were chemically restrained with ketamine, 8 mg/kg, IM; and xylazine, 1 mg /kg, IM, and subjected to electroejaculation protocol. We obtained 100% of antegrade ejaculate in treatments when the spayed female had her vagina impregnated with pheromone and 80% when she did not. Sperm motility was significantly different (p < 0.05) between controls and the test group (10.1 ± 4.5 and 43.0 ± 8.3, respectively). We concluded that the adopted electroejaculation protocol was efficient and that the PGF2α associated with sexual sensory stimulation can improve semen quality in dogs undergoing the procedure. 相似文献
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The High-producing Dairy Cow and its Reproductive Performance 总被引：2，自引：0，他引：2
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A Ortega-Pacheco ME Bolio-González RF Colin-Flores CH Sauri-Arceo E Gutiérrez-Blanco M Jiménez-Coello C Linde Forsberg 《Reproduction in domestic animals》2006,41(3):227-232
A Burdizzo castrator was evaluated for the neutering of dogs. Histological and morphological changes of spermatic cells and peripheral serum testosterone after challenge with a GnRH-analogue (gonadorelin) were assessed. There was a control group (G1), a surgically castrated group (G2) and a Burdizzo group (G3) divided in two, G3a receiving two crunches in each spermatic cord and G3b receiving one crunch in each spermatic cord. Sixteen days after application of the Burdizzo blood samples were taken from the dogs at 30 min interval during 2 h; after the second sample the dogs were treated with 1 mug/kg body weight of gonadorelin i.v. The same protocol of gonadorelin challenge was performed in G1 and G2 dogs. The G2 dogs were surgically castrated after the second blood sample, before the gonadorelin treatment, and the G1 dogs after the last blood sample. The excised gonads were examined histologically, and sperm smears were prepared from the caudae epididymidis. The testes and plexus pampiniformis of the G1 and G2 dogs had a normal histological appearance, and they had morphologically normal epididymal sperm cells. In all G3 dogs, there was an acute fibrosis with an inflammatory reaction in the plexus pampiniformis. The testes from the G3a dogs showed diffuse areas of infarction and degeneration of the parenchyma. Similar but less diffuse lesions were seen in group 3b dogs. The deferent ducts from all G3 dogs showed vasitis and/or sperm granulomas. Azoospermia or sperm malformations were observed in the epididymal smears from the G3 dogs. Testosterone concentration in the G1 dogs increased after gonadorelin application (p < 0.0001). The G2 dogs had basal testosterone levels after castration (p < 0.001) and did not respond to gonadorelin. Groups 3a and b showed a slight but non-significant increase in testosterone concentration after gonadorelin challenge, supposedly due to the reduction of testicular blood flow and loss of testicular interstitial tissue. 相似文献
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SPS Ghuman DN Jones S Prabhakar RF Smith H Dobson 《Reproduction in domestic animals》2008,43(5):531-541
The present study examines the involvement of GABAA or B receptors in gonadotrophin‐releasing hormone (GnRH) release in vitro and determines whether oestradiol modulates γ‐aminobutyric acid (GABA)–GnRH interaction. Within 10 min after ewe killing, hypothalamic slices were dissected and placed in oxygenated Minimum Essential Media (MEM)‐α at 4°C; within 2 h, slices were singly perifused at 37°C with oxygenated MEM‐α (0.15 ml/min), with or without oestradiol (24 pg/ml). After 4 h equilibration, fractions were collected for 4 h interposed with a 10 min exposure to specific GABAA or B receptor ligands (0.1–10 mm ). The GABAA or B agonists (muscimol or baclofen) did not greatly influence GnRH release. However, GnRH increased (p < 0.05) after exposure to 10 mm GABAA or B antagonists (bicuculline or CGP52432, respectively). The GABAA antagonist stimulated greater sustained GnRH release (p < 0.05) in the absence of oestradiol than in its presence. The bioactivity of the released GnRH was studied using a hypothalamus‐pituitary sequential double‐chamber perifusion. Only after exposure of hypothalamic slices to the GABAA antagonist, did the hypothalamic eluate stimulate luteinizing hormone release from pituitary fragments (p < 0.05) confirming that the GABAA antagonist stimulated release of biologically active GnRH. In summary, GnRH release from the hypothalamus is predominantly under GABAA receptor inhibitory control and this is attenuated in the presence of oestradiol. 相似文献
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SPS Ghuman DN Jones S Prabhakar RF Smith H Dobson 《Reproduction in domestic animals》2008,43(6):753-759
The present study investigates the influence of α1‐adrenoreceptors in GnRH release in vitro and determines whether oestradiol modulates α1‐adrenoreceptor‐GnRH interaction. Within 10 min after ewe sacrifice, saggital midline hypothalamic slices were dissected, placed in oxygenated Minimum Essential Media‐α (MEM‐α) at 4°C and within 2 h were singly perifused at 37°C with oxygenated MEM‐α (pH 7.4; flow rate 0.15 ml/min), either with or without oestradiol (24 pg/ml). After 4‐h equilibration, 10‐min fractions were collected for 4 h interposed with a 10‐min exposure at 60 min to specific α1‐adrenoreceptor agonist (methoxamine) or antagonist (thymoxamine) at various doses (0.1–10 mm ). The α1‐adrenoreceptor agonist (10 mm ) increased (p < 0.05) GnRH release at 90 min both in presence and absence of oestradiol. However, in presence of oestradiol, α1‐adrenoreceptor agonist (10 mm )‐induced GnRH release remained elevated (p < 0.05) for at least 60 min. The bioactivity of the released GnRH was studied using a hypothalamus–pituitary sequential double‐chamber perifusion. Only after exposure of hypothalamic slices to α1‐adrenoreceptor agonist (10 mm ), did the hypothalamic eluate stimulate LH release from pituitary fragments (n = 9, 7.8 ± 12.3–36.2 ± 21.6 ng/ml) confirming that the α1‐adrenoreceptor agonist stimulated release of biologically active GnRH. In summary, GnRH release from the hypothalamus is under stimulatory noradrenergic control and this is potentiated in the presence of oestradiol. 相似文献
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Co‐Expression of c‐Fos with Oestradiol Receptor α or Somatostatin in the Arcuate Nucleus,Ventromedial Nucleus and Medial Preoptic Area in the Follicular Phase of Intact Ewes: Alteration after Insulin‐Induced Hypoglycaemia 
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Fibrin–alginate hydrogel supports steroidogenesis,in vitro maturation of oocytes and parthenotes production from caprine preantral follicles cultured in group 下载免费PDF全文
下载免费PDF全文 IR Brito GM Silva AD Sales CH Lobo GQ Rodrigues RF Sousa AAA Moura CEM Calderón M Bertolini CC Campello J Smitz JR Figueiredo 《Reproduction in domestic animals》2016,51(6):997-1009
This study aimed to establish a culture system that improves the in vitro development of caprine preantral follicles. In a first experiment, follicles were encapsulated as a single unit per bead and cultured singly or in groups or with five follicles in the same alginate (ALG) bead for 18 days. In a subsequent experiment, the “five follicles per bead” design was chosen to culture in ALG, fibrin–alginate (FA) or hyaluronate (HA) for 18 days. In a third experiment, we chose the five follicles per bead in FA to culture for 30 days. The culture set‐up of five follicles per ALG bead increased antrum formation and follicle diameter compared to the other culture designs (p < .05). Moreover, under this condition, 44.44% of the oocytes from in vitro cultured preantral follicles reached meiotic resumption. A significant increase of follicle diameter occurred in attachment system and FA (p < .05), but the ALG condition reached the highest among all groups on day 18 (p < .05). Follicles encapsulated in matrix produced more estradiol and progesterone than attachment system (p < .05). The expression of MMP‐9 mRNA was higher in FA than in other groups (p < .05) and similar to antral follicles from in vivo control (p > .05). Only FA group resulted in oocytes matured. After 30 days, oocytes from preantral follicles in vitro grown in FA developed to eight‐cell parthenotes. In conclusion, a culture system using FA supported the development of caprine preantral follicles cultured in group and included in the same bead of hydrogel, improving the oocyte maturation and producing parthenotes. 相似文献
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The haemolytic RTX toxins of 27 isolates of Actinobacillus pleuropneumoniae, representing all serovars that have been isolated in Australia, were characterised. The quantity of protein secreted by these isolates into the media was not significantly different between serovars, but haemolytic activity was detected only in the unconcentrated supernatants from cultures of serovar 1 and 5 isolates. Haemolytic activity in supernatants of serovar 2, 3 and 7 isolates was detected only after the supernatants were concentrated. On Southern hybridisation blots, genomic DNA of serovar 1 and 5 isolates contained regions that were similar to the cloned structural genes for Apxl (apxIA) and for ApxII (apxIIA). In contrast, genomic DNA of serovar 2,3 and 7 isolates only contained regions similar to, if not identical with, the cloned apxIIA gene. The haemolytic activity of the culture supernatant depends on the type or composition of media and adaptability of the bacteria to in-vitro cultivation. Low passage cultures of A pleuropneumoniae, which were characterised by waxy colonies, produced significantly weaker haemolytic activity than A pleuropneumoniae after several passages in vitro. 相似文献
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SPS Ghuman R Morris DG Spiller RF Smith H Dobson 《Reproduction in domestic animals》2010,45(6):1065-1073
This study investigated possible integrated links in the neuroanatomical pathways through which the activity of neurones in the paraventricular nucleus and arcuate nucleus may modulate suppression of gonadotrophin‐releasing hormone (GnRH) secretion during stressful situations. Double‐label immunofluorescence and laser scanning confocal microscopy were used to examine the hypothalamic sections from the follicular phase ewes. Noradrenergic terminals were in close contact with 65.7 ± 6.1% corticotrophin‐releasing hormone (CRH) and 84.6 ± 3.2% arginine vasopressin (AVP) cell bodies in the paraventricular nucleus but not with β‐endorphin cell bodies in the arcuate nucleus. Furthermore, γ‐amino butyric acid (GABA) terminals were close to 80.9 ± 3.5% CRH but no AVP cell bodies in the paraventricular nucleus, as well as 60.8 ± 4.1%β‐endorphin cell bodies in the arcuate nucleus. Although CRH, AVP and β‐endorphin cell terminals were identified in the medial pre‐optic area, no direct contacts with GnRH cell bodies were observed. Within the median eminence, abundant CRH but not AVP terminals were close to GnRH cell terminals in the external zone; whereas, β‐endorphin cells and terminals were in the internal zone. In conclusion, neuroanatomical evidence is provided for the ewe supporting the hypothesis that brainstem noradrenergic and hypothalamic GABA neurones are important in modulating the activity of CRH and AVP neurones in the paraventricular nucleus, as well as β‐endorphin neurones in the arcuate nucleus. These paraventricular and arcuate neurones may also involve interneurones to influence GnRH cell bodies in medial pre‐optic area, whereas the median eminence may provide a major site for direct modulation of GnRH release by CRH terminals. 相似文献