Testosterone Influences Water Transport in Porcine Granulosa Cells     

M Grzesiak  L Williams  MR Luck 《Reproduction in domestic animals》2013,48(4):e52-e54

The development of antral ovarian follicles entails fluid accumulation, but the mechanisms regulating water flux are unknown. Aquaporins are small, integral membrane proteins facilitating passive movement of water, some of which are known to be regulated by steroid hormones. The aim of this study was to determine whether testosterone (T) influences water transport in porcine granulosa cells. To assess water movement, the swelling of granulosa cells when moved from isotonic (319 mOsm) to hypotonic (95 mOsm) medium was measured after 12‐hour pre‐incubation in the presence of either testosterone (T), the antiandrogen 2‐hydroxyflutamide (HF) or HF and T together. Pre‐incubation with T increased the swelling of granulosa cells (p < 0.01) and this was abolished by HF (p < 0.001). Neither T nor HF affected cells in isotonic medium (319 mOsm). The results indicate that T acting via intracellular androgen receptors increases water permeability of porcine granulosa cells, probably through the regulation of aquaporin activity.  相似文献   

Abomasal parasite syndrome in North American elk (Cervus elaphus canadensis)     

MR Woodbury  NMA Parry 《New Zealand veterinary journal》2013,61(4):235-240

CASE HISTORY An 18-month clinical course of chronic ill-thrift, weight loss and emaciation, and eventual death occurred in a group of 520 translocated elk of mixed age and sex. Trans-location was carried out without regard to animal welfare or health risks associated with the translocation. Mortality was approximately 84% (436/520) despite supportive nutritional and medical treatment.

PATHOLOGICAL FINDINGS: General clinical and post-mortem examinations indicated only Se and Cu imbalances and nutritional inadequacy. Additional purposeful post-mortem examination and histological evaluation of tissue sections from four of the affected adult elk demonstrated elevated abomasal pH and proliferative abomasal lesions as the most significant findings, consistent with Type-II ostertagiosis; intra-lesional nematodes were seen in the abomasum of two animals.

DIAGNOSIS: Fading elk syndrome, or abomasal parasite syndrome in elk.

CLINICAL RELEVANCE: Abomasal parasite syndrome initiated by Type-II ostertagiosis should be considered as a differential diagnosis in cases of ill-thrift and wasting in elk or elk-red deer hybrids. Changes to the architecture and secretory function of the abomasal wall lead to apparently irreversible digestive pathophysiology and nutritional disease.  相似文献   

Evaluation of a point‐of‐care electrochemical meter to detect subclinical ketosis and hypoglycaemia in lactating dairy cows          下载免费PDF全文

A Zakian  M Tehrani‐Sharif  MR Mokhber‐Dezfouli  M Nouri  PD Constable 《Australian veterinary journal》2017,95(4):123-128

  相似文献   

Characterisation of adult green lacewing (Chrysoperla carnea) digestive physiology: impact of a cysteine protease inhibitor and a synthetic pyrethroid     

Evan A Mulligan  Natalie Ferry  Lise Jouanin  Jörg Romeis  Angharad MR Gatehouse 《Pest management science》2010,66(3):325-336

BACKGROUND: In spite of concern regarding potential non‐target effects of GM crops, few studies have compared GM pest control with conventional methods. The impacts of cypermethrin and oilseed rape expressing oryzacystatin‐1 (OC‐1) were compared in this study on the predator Chrysoperla carnea (Stephens). RESULTS: Adults fed purified rOC‐1 showed a subtle shift in digestive protease profile, with an increasing reliance on serine proteases (chymotrypsin), increase in aspartic proteases and a slight reduction in elastase activity. Although there were no effects on mortality, onset of oviposition was delayed; however, once egg production commenced, egg laying and hatching success rates were comparable with those of controls. Oryzacystatin‐1 expressed in pollen showed no detrimental effects. Cypermethrin had no effect on mortality owing to high levels of non‐specific esterase activity resulting in partial breakdown of the insecticide. In spite of this, there was a significant delay in onset of oviposition and a significant reduction in egg production and viability. CONCLUSION: This study demonstrates the potential for pest management to impact on predators, but importantly it highlights the ability of the predator to detoxify/respond to treatments with different modes of action. In this case, exposure to an insecticide carried a greater fitness cost than exposure to a protease inhibitor expressed in transgenic crops. Copyright © 2009 Society of Chemical Industry  相似文献   

Bosonic stimulation in the formation of a bose-einstein condensate     

H Miesner  DM Stamper-Kurn  MR Andrews  DS Durfee  S Inouye  W Ketterle 《Science (New York, N.Y.)》1998,279(5353):1005-1007

The formation of a Bose-Einstein condensate of a dilute atomic gas has been studied in situ with a nondestructive, time-resolved imaging technique. Sodium atoms were evaporatively cooled close to the onset of Bose-Einstein condensation and then suddenly quenched to below the transition temperature. The subsequent equilibration and condensate formation showed a slow onset distinctly different from simple relaxation. This behavior provided evidence for the process of bosonic stimulation, or coherent matter-wave amplification, crucial to the concept of an atom laser.  相似文献   

Proliferative enteritis: endemic in Australian piggeries?     

MR ALDERTON 《Australian veterinary journal》1993,70(8):311-311

  相似文献   

Antibiotics for the preservation of koala (Phascolarctos cinereus) semen     

SD JOHNSTON  D. OBOYLE  AJ FROST  MR MCGOWAN  A. TRIBE  D. HIGGINS 《Australian veterinary journal》1998,76(5):335-338

Aim To determine the normal microbial flora of the koala ejaculate and prepuce in order to select appropriate antibiotics for addition into diluents designed for the preservation of semen.
Procedure Bacteriological samples of the koala prepuce (n = 12) and ejaculate (n = 20) were submitted for microbial culture and sensitivity testing. Microbial flora of ejaculates collected by electroejaculation and artificial vagina were compared. The effects of varying concentrations of penicillin G and gentamicin on sperm motility and on the growth of bacteria in diluted semen stored at room temperature and 16°C over a 24 h period were investigated.
Results A range of bacteria was isolated from the koala prepuce and ejaculate. The predominant organisms in semen collected by electroejaculation and artificial vagina were Corynebacterium spp, none of which could be assigned to any recognised species. The addition of penicillin G and gentamicin to a PBS-based diluent at dose rates of 1000 to 2000 IU/mL and 100 to 200 m g/mL respectively, resulted in no adverse effect on sperm motility over a 24 h incubation period. Penicillin G (1000 IU/mL) and gentamicin (100 m g/mL) prevented growth of bacterial contaminants in diluted koala semen.
Conclusion By controlling the growth of bacteria in extended koala semen, penicillin G and gentamicin are likely to lengthen the period by which spermatozoa can be stored at 16°C and reduce the possibility of disease transmission during artificial insemination procedures.  相似文献   

The long‐term effect of α‐ketoglutarate,given early in postnatal life,on both growth and various bone parameters in pigs     

N. K. Andersen  M. R. Tatara  W. Krupski  P. Majcher  A. P. Harrison 《Journal of animal physiology and animal nutrition》2008,92(5):519-528

The long‐term effect of α‐ketoglutarate (AKG) given for 21–24 days post‐partum, on the skeleton of commercial pigs, was investigated. In experiment A, 12 pigs were given AKG [0.1 g/kg of body weight (b.w.) per day per os], while 12 controls were administered vehicle. At day 169, the left and right femur, humerus and sixth ribs were analysed for mechanical and geometrical properties and quantitative computed tomography. In experiment B, 32 piglets were divided equally into an AKG group (0.3 g/kg of b.w. per day) or a control group. Blood, taken at days 24 and 53 was analysed for plasma 17 β‐oestradiol. The main bone effect of AKG was to increase bone length in the sixth rib (7.3%, p < 0.01), ultimate strength (23%, p < 0.05), Young´s modulus (52%, p < 0.001) and maximum elastic strength (31%, p = 0.056) compared with controls. In both experiments, AKG preferentially increased the growth of female piglets, whilst for male piglets AKG had the opposite effect. In addition, AKG elevated plasma 17 β‐oestradiol levels compared to those of controls at the end of the period of treatment (20%, p = 0.002). It is concluded that AKG has long‐term effects on rib properties when given early in postnatal life whilst it elevates plasma 17 β‐oestradiol levels only so long as it is being administered.  相似文献   

Heterologous In Vitro Fertility Evaluation of Cryopreserved Iberian Red Deer Epididymal Spermatozoa with Zona-intact Sheep Oocytes and its Relationship with the Characteristics of Thawed Spermatozoa     

AJ Soler  N Poulin  MR Fernández-Santos  Y Cognie  MC Esteso  JJ Garde  P Mermillod 《Reproduction in domestic animals》2008,43(3):293-298

A heterologous in vitro system, using zona‐intact sheep oocytes, was used to evaluate the relationship between sperm factors of Iberian red deer thawed epididymal sperm and the percentage of cleaved oocytes. Epididymal spermatozoa were recovered from six males, diluted with freezing extender and cryopreserved. After thawing sperm motility (SM) and acrosome and membrane integrities were evaluated. Again, these parameters were assessed after incubation in freezing extender at 37°C for 2 h. After cryopreservation the values for SM and acrosome and membrane integrities were high (～80, 80 and 70% respectively). However, these values significantly decreased after incubation (～59, 62 and 47% respectively). Red deer thawed epididymal sperm fertilized zona‐intact sheep oocytes, although the percentage of cleaved oocytes was low (～22%). No relationship was found between sperm parameters assessed after thawing and the percentage of cleaved oocytes. Likewise, any sperm parameter evaluated after incubation was assessed in relation to the percentage of cleaved oocytes. However, acrosome and membrane integrities were near to significance (p = 0.06 and p = 0.09 respectively). Then, we conducted a reduced model with these two variables and both were related to the percentage of cleaved oocytes (p = 0.02 and p = 0.04 respectively). Thus, acrosome and membrane integrities were related to the percentage of cleaved oocytes negatively and positively respectively. It was concluded that the classical parameters assessed in deer thawed sperm samples can be good predictors of the ability to fertilize zona‐intact sheep oocytes.  相似文献   

Oestrous sheep serum balances ROS levels to supply in vitro capacitation of ram spermatozoa          下载免费PDF全文

E Del Olmo  O García‐Álvarez  A Maroto‐Morales  M Ramón  M Iniesta‐Cuerda  F Martinez‐Pastor  V Montoro  AJ Soler  JJ Garde  MR Fernández‐Santos 《Reproduction in domestic animals》2016,51(5):743-750

Reactive oxygen species (ROS) are fundamental for intracellular signalling. In spermatozoa, they are involved both to apoptosis and to capacitation, and changes in ROS levels can alter the balance between these two processes. Oestrous sheep serum (OSS) is considered an efficient agent for in vitro capacitation of ram spermatozoa. We have explored the effects of OSS on ram sperm physiology, especially on ROS production, during in vitro capacitation. Semen samples from 15 rams were cryopreserved. After thawing, samples were submitted to four treatments: control (CTL), 10% OSS supplementation for in vitro sperm capacitation, caspase inhibitor (INH, Z‐VAD‐FMK 100 μM) and OSS (10%) plus caspase inhibitor (I + E). Sperm samples were incubated for 30 min at 38.5°C and 5% CO₂ and evaluated motility and kinetic parameters by computer‐assisted semen analysis (CASA) and viability (propidium iodide), apoptotic‐like membrane changes (YO‐PRO‐1), acrosomal status (PNA‐FITC), intracellular calcium (FLUO‐3), membrane fluidity (M540) and ROS production (CM‐H₂DCFDA) by flow cytometry. OSS induced changes in kinetic parameters compatible with capacitation, with a decrease in the percentage of progressive motility and linearity, and an increase in the amplitude of the lateral displacement of the sperm head (p < .05). Moreover, OSS increased the proportion of M540+ viable spermatozoa, YO‐PRO‐1+ and acrosome‐reacted spermatozoa (p < .05). After incubation, OSS and I+E achieved lower ROS levels (p < .05). Ca²⁺ levels did not change with the incubation, but were slightly higher (p < .05) when both OSS and the inhibitor were present. We suggest that OSS may modulate ROS levels, allowing intracellular signalling for capacitation to occur while preventing higher levels that could trigger apoptosis.  相似文献