Luteolytic Effect of Prostaglandin F_2α on Bovine Corpus Luteum Depends on Cell Composition and Contact     

AJ Korzekwa  JJ Jaroszewski  I Woclawek-Potocka  MM Bah  DJ Skarzynski 《Reproduction in domestic animals》2008,43(4):464-472

Prostaglandin F_2α (PGF_2α) is a main luteolytic factor in vivo; however, its direct luteolytic influence on steroidogenic cells of bovine corpus luteum (CL) is controversial and not fully understood. The aim of the study was to clarify PGF_2α action on bovine CL in different in vivo and in vitro conditions and to examine whether the contact among all main types of CL cells is necessary for luteolytic PGF_2α action. In experiment 1, the bovine CL (day 15 of the oestrous cycle) was perfused using in vivo microdialysis system with dinoprost (an analogue of PGF_2α) for 0.5 h. Dinoprost caused a short‐time increase in progesterone (P4), whose concentration decreased thereafter (at 6‐, 10‐, 12‐ and 24‐h after treatment). In experiment 2, the direct effect of PGF_2α on P4 accumulation in CL steroidogenic cells cultured in monolayer (day 15 of the cycle) was determined. PGF_2α after 24 h of incubation increased P4 accumulation in steroidogenic CL cells. In experiment 3 steroidogenic, endothelial CL and immune cells (day 15 of the cycle) were incubated with PGF_2α in cocultures for 24 h in glass tubes and the levels of P4, stable metabolites of nitric oxide (NO) and leukotriene (LT) C₄ were determined. Although PGF_2α treatment increased P4 secretion in homogeneous steroidogenic CL cell culture, the decrease in P4 secretion in cocultures of all types of CL cells was observed. The secretion of NO and LTC₄ increased after the treatment of PGF_2α both in pure cultures of CL cells and in cocultures. The interactions between endothelial and immune cells with steroidogenic CL cells are needed for luteolytic PGF_2α action within the bovine CL. Our results indicate that the cell coculture model, including the main types of CL cells, is the most approximate to study PGF_2α role in vitro.  相似文献   

A Study on Postpartum Metritis in Iraqi Buffalo Cows: Bacterial Causes and Treatment     

OI Azawi  SN Omran  JJ Hadad 《Reproduction in domestic animals》2008,43(5):556-565

The objectives of the present study were to determine the relationship between bacteriological findings, clinical signs and histopathological changes in postpartum metritis. Evaluation of the treatment efficiency of using systemic or intra‐uterine infusion of antibiotics with some hormonal preparations for the treatment of postpartum metritis. Data were collected from 50 buffalo cows with history of calving of more than 1 month. All buffaloes were subjected to detailed clinical examination including external inspection, vaginoscopy and transrectal palpation of the cervix, uterus and ovaries. Swabs for bacteriology and biopsies for histopathology were collected from uterine lumen from each buffalo included in the present study. Bacteria identified using API systems following aerobic and anaerobic cultures. Vaginal mucus scored for character, odour and estimation of polymorphonuclear cells (PMNs). Treatment conducted using oxytetracycline in local intrauterine infusion or systemically with hormonal treatment including prostaglandinF2α (PGF2α) and oestradiol benzoate. Results revealed that the most predisposing factor for postpartum uterine infection was retained placenta and toxic puerperal metritis. The most prevalent bacteria in uterine lumen were Escherichia coli, Archanobacterium pyogenes, Bacteroides fragilis and Fusobacterium necrophorum the most prevalent bacteria in buffaloes with postpartum metritis. A. pyogenes and F. necrophorum were an important pathogens causing severe uterine inflammation as found in histopathological examinations. Buffaloes with postpartum metritis showed good clinical cure when oxytetracycline injected systemically with PGF2α. Intrauterine infusion of oxytetracycline had no advantage for the treatment of uterine infection in buffalo cows with postpartum metritis. PGF2α improved clinical cure of buffaloes with postpartum metritis.  相似文献   

An In Vitro Evaluation of Biochemical Processes Involved in Lead‐Induced Changes on Ram Spermatozoa          下载免费PDF全文

P Castellanos  A Maroto‐Morales  O García‐Álvarez  JJ Garde  R Mateo 《Reproduction in domestic animals》2016,51(3):421-427

Lead (Pb²⁺) is a toxic heavy metal which interferes with several physiological processes regulated by Ca²⁺, including those characterized by changes of the membrane stability and the motility of spermatozoa necessary for the fertilization of the oocyte. In this study, ejaculated sperm from six rams (Ovis aries) have been incubated in vitro with or without 50 ng Pb²⁺/ml during 30 min and in the presence or absence of three different potential modulators of the effects of Pb²⁺ on changes in the sperm membrane before fertilization: charybdotoxin, quinacrine and staurosporine. Sperm samples incubated with Pb²⁺ have shown significant reductions in acrosome integrity and sperm viability and an increase in progressive movement. None of the studied potential modulators had a protective effect against Pb²⁺ action. On the contrary, Pb²⁺‐incubated sperm in the presence of staurosporine had lower acrosome integrity, and lower sperm viability was observed when spermatozoa were incubated with Pb²⁺ + charybdotoxin. Quinacrine was the only tested substance capable of increasing the concentration of Pb²⁺ in spermatozoa; thus, the enhancement of Pb²⁺ effects produced by staurosporine and charybdotoxin was not produced by an increased uptake of Pb²⁺ by spermatozoa. However, the increase of intracellular Pb²⁺ in those spermatozoa incubated with quinacrine did not result in an adverse effect on sperm motility or viability although the acrosome integrity was negatively affected.  相似文献   

The Effect of Oxidative Stress on Thawed Bulk‐Sorted Red Deer Sperm          下载免费PDF全文

L Anel‐López  O García‐Álvarez  I Parrilla  D Del Olmo  MR Fernández‐Santos  AJ Soler  A Maroto‐Morales  JA Ortiz  DV Alkmin  T Tarantini  J Roca  EA Martínez  JM Vazquez  JJ Garde 《Reproduction in domestic animals》2016,51(3):407-414

The aims of this study were to assess the effects of the sex‐sorting process on post‐thaw sperm quality as well as on induced oxidative stress damage (H₂O₂ 0 mm  = H000; H₂O₂ 50 mm  = H050; H₂O₂ 100 mm  = H100) and the protective action of reduced glutathione (GSH) and Trolox, when comparing sorted (BSS) and non‐sorted (NS) red deer spermatozoa incubated at 37°C. Sperm samples from three stags were collected by electroejaculation and frozen. Immediately after thawing, sperm motility was higher (p < 0.05) for NS (59% ± 3.3) than BSS (36.9% ± 5.8) sperm. Furthermore, the percentage of apoptotic sperm was higher (p < 0.05) for BSS (21.6% ± 5.0) than NS sperm (14.6% ± 1.2). The presence of H₂O₂ increased DNA damage in NS (H000 = 4.1% ± 0.9; H050 = 9.3% ± 0.7; and H100 = 10.9% ± 2.3), but not in BSS sperm. However, in the presence of oxidant, GSH addition improved (p < 0.05) sperm motility in both groups of sperm samples as compared to their controls (NS: 44.5 ± 4.8 vs 21.1 ± 3.9 and BSS: 33.3 ± 8.1 vs 8.9 ± 1.8). These results demonstrate that the sperm‐sorting process induces sublethal effects, albeit selecting a sperm population with a chromatin more resistant to oxidative stress than that in non‐sorted sperm. Moreover, addition of GSH at 1 mm may be a good choice for maintaining the quality of stressed sperm samples, unlike Trolox, which inhibited sperm motility.  相似文献   

Selection of red deer spermatozoa with different cryoresistance using density gradients          下载免费PDF全文

O García‐Álvarez  AJ Soler  Z Maulen  A Maroto‐Morales  M Iniesta‐Cuerda  A Martín‐Maestro  MR Fernández‐Santos  JJ Garde 《Reproduction in domestic animals》2016,51(6):895-900

The objective of sperm selection media is selecting the best spermatozoa and to remove seminal plasma and diluent for using them in assisted reproductive techniques. It is known that individuals show different cryoresistance in response to the same freezing procedure. Our hypothesis was that the efficacy of selection media could be dissimilar for samples with different sperm quality after thawing. Epididymal sperm samples from mature Iberian red deer were collected and frozen. Males were classified as with high post‐thaw sperm quality when sperm motility (SM) ≥ 70%, or as with low post‐thaw sperm quality when SM ≤ 69%. Samples were centrifuged using the following density gradients (DG): Percoll^®, Puresperm^® and Bovipure^?, and several functional sperm parameters were assessed after sperm selecting and washing. Males classified with high sperm quality had higher post‐thawing values (p > .05) for all parameters evaluated, except for linearity index, than those categorized as low sperm quality. After selection, some sperm characteristics improved (viability, apoptosis and mitochondrial activity) for both groups, showing the males with high sperm quality higher values in all sperm parameters except for kinematic traits and DNA fragmentation index (%DFI), regardless of DG. Bovipure^? yield lower values of sperm motility, viability, apoptosis and mitochondrial activity in relation to Percoll^® and Puresperm^® considering both quality groups. There was an interaction between the type of DG and sperm quality group for sperm viability (p = .040) and apoptosis (p = .003). Thus, Percoll^® selected less live and more apoptotic spermatozoa than Puresperm^® and Bovipure^? for males with low sperm quality. In conclusion, the DG are more efficient selecting spermatozoa from samples with high sperm quality, acting differently depending on initial sperm quality.  相似文献   

Effects of Egg Yolk and Cooling Rate on the Survival of Refrigerated Red Deer (Cervus elaphus hispanicus) Epididymal Spermatozoa     

MR Fernández-Santos  MC Esteso  AJ Soler  V Montoro  JJ Garde 《Reproduction in domestic animals》2006,41(2):114-118

Egg yolk is a common component to sperm refrigeration for most of the deer species, the role of which is to protect sperm membranes against cold shock. In addition, there have been many studies of conservation of ejaculated semen from stags, but few have been reported for epididymal spermatozoa. This work was designed to investigate the combined effects of cooling rates (slow: 0.23 degrees C/min vs rapid: 4.2 degrees C/min) from room temperature to 5 degrees C, and egg-yolk concentration (0, 5 or 20%) in the extender on the survival of Iberian red deer epididymal spermatozoa refrigerated at 5 degrees C. Heterospermic sperm samples were diluted to a final sperm concentration approximately 400x10(6) sperm/ml with a Tris-citrate-fructose (TCF)-egg-yolk diluent. Sperm quality was in vitro judged by microscopic assessments of individual sperm motility [sperm motility index (SMI)], and of plasma membrane (hypo-osmotic swelling test) and acrosome (NAR) integrities. Our results first showed that the presence of egg yolk in the extender significantly improves (p=0.01) the viability and sperm motility after sperm dilution. In addition, acrosome and plasma membrane integrities post-refrigeration did not differ significantly between cooling procedures; however, the SMI differed significantly between cooling procedures (slow: 46.6% vs rapid: 50.0%; p=0.01). Our results also showed that sperm quality was significantly (p<0.01) affected by the combined effects of egg-yolk concentration and cooling procedure, being rapid cooling with 20% of egg yolk the most suitable combination for epididymal sperm refrigeration. In conclusion, egg-yolk improved red deer epididymal spermatozoa characteristics after dilution. Rapid cooling protocol using TCF with 20% egg-yolk significantly improved sperm motility of red deer epididymal spermatozoa after cooling.  相似文献   

Assessment of florfenicol as a possible treatment for chlamydiosis in koalas (Phascolarctos cinereus)          下载免费PDF全文

C Budd  C Flanagan  A Gillett  J Hanger  JJ Loader  M Govendir 《Australian veterinary journal》2017,95(9):343-349

  相似文献   

红松不同嫁接方法成活率及生长势初探   总被引：1，自引：0，他引：1  

宋德利  姬少玲  张立民 《吉林林业科技》2007,36(3):11-13

在同一生长季节对红松进行了髓心形成层贴接法和劈接法嫁接对比试验。结果表明:采取髓心形成层贴接法嫁接平均成活率为62%,劈接法为88%。髓心形成层贴接法嫁接成活后接穗平均生长量为5.9 cm,劈接法为11.8 cm,较髓心形成层贴接法提高了100%。经方差分析,两种方法嫁接成活率及成活后接穗平均生长量差异均极显著,说明红松采取劈接法嫁接优于髓心形成层贴接法。  相似文献   

Gold nanoelectrodes of varied size: transition to molecule-like charging   总被引：1，自引：0，他引：1  

S Chen  RS Ingram  MJ Hostetler  JJ Pietron  RW Murray  TG Schaaff  JT Khoury  MM Alvarez  RL Whetten 《Science (New York, N.Y.)》1998,280(5372):2098-2101

A transition from metal-like double-layer capacitive charging to redox-like charging was observed in electrochemical ensemble Coulomb staircase experiments on solutions of gold nanoparticles of varied core size. The monodisperse gold nanoparticles are stabilized by short-chain alkanethiolate monolayers and have 8 to 38 kilodaltons core mass (1.1 to 1.9 nanometers in diameter). Larger cores display Coulomb staircase responses consistent with double-layer charging of metal-electrolyte interfaces, whereas smaller core nanoparticles exhibit redox chemical character, including a large central gap. The change in behavior is consistent with new near-infrared spectroscopic data showing an emerging gap between the highest occupied and lowest unoccupied orbitals of 0.4 to 0.9 electron volt.  相似文献   

Studies on the Intracellular Ca²⁺ Concentration of Frozen–Thawed Dog Spermatozoa: Influence of Equex from Different Sources, Two Thawing Diluents and Post-thaw Incubation in Capacitating Conditions     

AI Peña  L López-Lugilde  M Barrio  JJ Becerra  LA Quintela  PG Herradón 《Reproduction in domestic animals》2003,38(1):27-35

The addition of 0.5% (v/v) of Equex STM Paste (Nova Chemical Sales, Scituate Inc., MA, USA), whose active ingredient is sodium dodecyl sulphate (SDS), to a Tris–egg yolk extender was demonstrated to improve the longevity of frozen–thawed dog spermatozoa during in vitro incubation at 38°C. The aim of the first experiment was to compare the effects of two SDS‐containing compounds, Equex STM Paste and Equex Pasta (Minitüb, Tiefenbach, Germany), when added to a Tris–egg yolk based extender, on the post‐thaw longevity of dog spermatozoa, as well as on the intracellular Ca²⁺ concentration of spermatozoa, during post‐thaw incubation at 38°C. The post‐thaw sperm survival and longevity, as well as the quality of the sperm movement, were significantly better when using Equex STM Paste. Such prolonged sperm longevity, however, was associated to a higher intracellular Ca²⁺ concentration in a large subpopulation of the live spermatozoa. A second experiment was aimed to evaluate the effects of sperm dilution immediately post‐thaw with a Tris buffer containing glucose or fructose. The two Tris buffers were no different for any of the sperm parameters studied. The aim of a third experiment was to evaluate the sperm longevity, motility patterns and intracellular Ca²⁺ concentration of cryopreserved dog spermatozoa during post‐thaw incubation in capacitating conditions [canine capacitating medium (CCM) with or without 5 μg/ml of heparin]. Heparin had no significant effects on any of the sperm parameters evaluated. During the first 8 h of incubation, the majority of the live spermatozoa had a high intracellular Ca²⁺ content. However, after 8–10 h of incubation, it had significantly declined. The highest proportion of fast motile sperm, and the highest curvilinear velocity, average path velocity and amplitude of lateral head displacement for the total motile sperm were observed during the 2–4‐h incubation period. It was concluded that: (a) the addition of 0.5% (v/v) of Equex STM Paste to a Tris–egg yolk based extender significantly improved the post‐thaw longevity of dog spermatozoa, but the same concentration of Equex Pasta had no significant beneficial effects; (b) sperm dilution after thawing with a Tris buffer containing glucose or fructose made no difference in post‐thaw sperm longevity; (c) the addition of 5 μg/ml of heparin to CCM had no significant capacitating effects on frozen–thawed dog spermatozoa.  相似文献