Circulating ghrelin concentrations fluctuate relative to nutritional status and influence feeding behavior in cattle     

Wertz-Lutz AE  Knight TJ  Pritchard RH  Daniel JA  Clapper JA  Smart AJ  Trenkle A  Beitz DC 《Journal of animal science》2006,84(12):3285-3300

The objective of these experiments was to establish the relationship of plasma ghrelin concentrations with feed intake and hormones indicative of nutritional state of cattle. In Exp.1, 4 steers (BW 450 +/- 14.3 kg) were used in a crossover design to compare plasma ghrelin concentrations of feed-deprived steers with those of steers allowed to consume feed and to establish the relationship of plasma ghrelin concentrations with those of GH, insulin (INS), glucose (GLU), and NEFA. After adaptation to a once-daily feed offering (0800), 2 steers continued the once-daily feeding schedule (FED), whereas feed was withheld from the other 2 steers (FAST). Serial blood samples were collected via indwelling jugular catheter from times equivalent to 22 h through 48 h of feed deprivation. Average plasma ghrelin concentrations were greater (P < 0.001) in FAST compared with FED (690 and 123 +/- 6.5 pg/mL) steers. Average plasma ghrelin concentrations for FED steers prefeeding were elevated (P < 0.001) when compared with those postfeeding (174 and 102 +/- 4.2 pg/mL, respectively). Average plasma GH concentration was elevated (P < 0.05) for FAST steers compared with FED steers. Plasma GLU concentrations were not different; however, for FAST steers, NEFA concentrations were elevated (P < 0.001) and INS concentrations were decreased (P < 0.001). In Exp. 2, 4 steers (BW 416 +/- 17.2 kg) were used in a crossover design to determine the effects of i.v. injection of bovine ghrelin (bGR) on plasma GH, INS, GLU, and NEFA concentrations; length of time spent eating; and DMI. Steers were offered feed once daily (0800). Serial blood samples were collected from steers via indwelling jugular catheter. Saline or bGR was injected via jugular catheter at 1200 and 1400. A dosage of 0.08 microg/kg of BW bGR was used to achieve a plasma ghrelin concentration similar to the physiological concentration measured in a FAST steer in Exp. 1 (1,000 pg/mL). Injection of bGR resulted in elevated (P < 0.005) plasma GH concentrations after the 1200 but not the 1400 injection. Plasma INS, GLU, and NEFA concentrations were not affected by bGR injection. For the combined 1-h periods postinjection, length of time spent eating was greater (P = 0.02) and DMI tended to be increased (P = 0.06) for bGR steers. These data are consistent with the hypothesis that ghrelin serves as a metabolic signal for feed intake or energy balance in ruminants.  相似文献   

α‐6 Integrin Expression in Bovine Spermatogonial Cells Purified by Discontinuous Percoll Density Gradient     

FRO de Barros  RA Worst  GCP Saurin  CM Mendes  MEOA Assumpção  JA Visintin 《Reproduction in domestic animals》2012,47(6):887-890

The study of spermatogonial stem cells (SSCs) provides a model to better understand adult stem cell biology. Besides the biomedical potential to perform studies of infertility in many species, SSCs hold a promising application at animal transgenesis. Because stem cells are thought to be associated with basement membranes, expression of α‐6 integrin has been investigated as a marker of type A spermatogonial cells, which are considered SSCs because of their undifferentiated status and self‐renewal ability. In this manner, the aim of this study was to isolate type A SSCs from adult bulls by a two‐step enzymatic procedure followed by a discontinuous Percoll density gradient purification and verify the expression of α‐6 integrin by flow cytometry and real‐time RT‐PCR before and after Percoll purification. Spermatogonial cells were successfully obtained using the two‐step enzymatic digestion. An average of 1 × 10⁵ viable cells per gram of testis was isolated. However, the discontinuous Percoll did not purify isolated cells regarding α‐6 integrin expression. Flow cytometry analysis demonstrated no differences in the α‐6 integrin expression between cell samples before and after Percoll purification (p = 0.5636). The same was observed in the real‐time PCR analysis (p > 0.05). In addition to α‐6 integrin, the expression of GFRa‐1 and PGP9.5, known bovine SSCs markers, was detected in all samples studied. Considering that Percoll can reduce cell viability, it is possible to conclude that Percoll density gradient is not suitable to purify bovine SSC, according to α‐6 integrin expression.  相似文献   

Hemodynamic effects of sevoflurane in spontaneously breathing cats     

BH  Pypendop  JE Ilkiw  JA Bolich 《Veterinary anaesthesia and analgesia》2003,30(2):105-106

Sevoflurane has recently been introduced in feline anesthesia. However, its cardiovascular effects have not, to our knowledge, been reported in this species. Six healthy cats, aged 1.81 ± 0.31 years (mean ± SEM) and weighing 3.47 ± 0.11 kg, were studied. Anesthesia was induced and maintained with sevoflurane in oxygen. Body temperature was maintained between 38.5 and 39.55 °C. After instrumentation, end‐tidal sevoflurane concentration was randomly set at 1.25, 1.5, and 1.75 times the individual minimum alveolar concentration (MAC), determined in a previous study, according to a Latin Square Design. Thirty minutes of stabilization was allowed after each change of concentration. ECG and heart rate, systemic and pulmonary arterial pressures, central venous pressure (CVP), and core body temperature were continuously monitored and recorded. Inspired and end‐tidal oxygen, carbon dioxide, and sevoflurane concentrations were measured using a Raman spectrometer, calibrated every 80 minutes with three calibration gases of known sevoflurane concentration (1, 2, and 5%). Moreover, at selected times, pulmonary artery occlusion pressure and cardiac output (thermodilution) were measured, and arterial and mixed venous blood samples were collected for pH and blood gas analysis, hemoglobin concentration, hemoglobin oxygen saturation, packed cell volume (PCV) and total protein determination, and lactate concentration measurement. Cardiac index (CI), stroke index (SI), systemic and pulmonary vascular resistance indices, rate‐pressure product, left and right ventricular stroke work indices (LVSWI and RVSWI, respectively), arterial and mixed venous oxygen contents, oxygen delivery, oxygen consumption, and oxygen utilization ratio were calculated. Data were analyzed by a Repeated Measure Latin Square Design followed by a Tukey's test for 2 × 2 comparisons. Arterial pH significantly decreased from 7.40 ± 0.05 to 7.29 ± 0.07 with the administration of increasing concentrations of sevoflurane. Similarly, LVSWI decreased from 3.72 ± 0.60 to 2.60 ± 0.46 g m^?2. Mean arterial pressure, PaO₂, mixed venous pH, CI, SI, and oxygen delivery tended to decrease dose‐dependently, whereas CVP, PaCO₂, Pv CO₂, PCV, and arterial and mixed venous hemoglobin concentrations tended to increase dose‐dependently with the administration of sevoflurane. However, these trends did not reach statistical significance, possibly because of the limited number of animals studied. Sevoflurane seemed to induce dose‐dependent cardiovascular depression in cats.  相似文献   

Linking Phenology and Biomass Productivity in South Dakota Mixed-Grass Prairie     

Matthew Rigge  Alexander Smart  Bruce Wylie  Tagir Gilmanov  Patricia Johnson 《Strength and Conditioning Journal》2013,66(5):579-587

Assessing the health of rangeland ecosystems based solely on annual biomass production does not fully describe the condition of the plant community; the phenology of production can provide inferences about species composition, successional stage, and grazing impacts. We evaluated the productivity and phenology of western South Dakota mixed-grass prairie in the period from 2000 to 2008 using the normalized difference vegetation index (NDVI). The NDVI is based on 250-m spatial resolution Moderate Resolution Imaging Spectroradiometer (MODIS) satellite imagery. Growing-season NDVI images were integrated weekly to produce time-integrated NDVI (TIN), a proxy of total annual biomass production, and integrated seasonally to represent annual production by cool- and warm-season species (C₃ and C_4, respectively). Additionally, a variety of phenological indicators including cool-season percentage of TIN were derived from the seasonal profiles of NDVI. Cool-season percentage and TIN were combined to generate vegetation classes, which served as proxies of the conditions of plant communities. TIN decreased with precipitation from east to west across the study area. However, the cool-season percentage increased from east to west, following patterns related to the reliability (interannual coefficient of variation [CV]) and quantity of midsummer precipitation. Cool-season TIN averaged 76.8% of the total TIN. Seasonal accumulation of TIN corresponded closely (R² > 0.90) to that of gross photosynthesis data from a carbon flux tower. Field-collected biomass and community composition data were strongly related to TIN and cool-season percentage. The patterns of vegetation classes were responsive to topographic, edaphic, and land management influences on plant communities. Accurate maps of biomass production, cool- and warm-season composition, and vegetation classes can improve the efficiency of land management by facilitating the adjustment of stocking rates and season of use to maximize rangeland productivity and achieve conservation objectives. Further, our results clarify the spatial and temporal dynamics of phenology and TIN in mixed-grass prairie.  相似文献   

Aplysia gigantea toxicosis in 72 dogs in Western Australia     

RE Peacock  G Hosgood  KL Swindells  L Smart 《Australian veterinary journal》2013,91(7):292-295

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Endocrine Regulation of the Establishment of Spermatogenesis in Pigs     

KC Caires  JA Schmidt  AP Oliver  J de Avila  DJ McLean 《Reproduction in domestic animals》2008,43(S2):280-287

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Identification of RSVP14 and RSVP20 components by two-dimensional electrophoresis and Western-blotting.   总被引：1，自引：0，他引：1  

JA Cardozo  M Fernández‐Juan  JA Cebrián‐Pérez  T Muiño‐Blanco 《Reproduction in domestic animals》2008,43(1):15-21

We have already shown that RSVP14 and RSVP20, two ram seminal plasma (SP) proteins postulated to be involved in sperm capacitation and gamete interaction can protect spermatozoa against cold-shock. In this study, we use two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) for the analysis of SP proteins of Rasa Aragonesa rams, using enhanced protein solubilization in the presence of tributyl phosphine (TBP) and a polyacrylamide linear gradient gel with a narrow pH range (4-7). The image analysis of the 2D map detected 195 protein spots, with isoelectric points (pIs) ranging from 4.5 to 6.6, and molecular weight (M(r)) from 11.7 to 90.4. Staining of 2D gels with Pro-Q Emerald 300 Glycoprotein Stain revealed that most significant proteins in ram SP are glycosylated. The removing of protein N-linked oligosaccharides improved the gel resolution. 2D-PAGE analysis of the whole fraction 6 (F6) separated from ram SP by exclusion chromatography showed six main protein spots, four (a, b, c, d) in the 14 kDa and two (e, f) in the 20 kDa region. Western-blot analyses indicated that the anti-P14 antibody recognized four spots on the SP map, 4, 5, 6 and 7, that matched with spots a, b, c, d of F6 map. The anti-P20 antibody recognized spots 13 and 14 of SP map that corresponded to spots e, f of F6 map. The deduced sequences by de novo sequencing evidenced that protein spots 7 and 13 have significant similarities to BSP family, while protein spots 4 and 14 did not appear to be homologous with any reported protein in the current mammalian Proteinbank databases.  相似文献   

Effect of Chemical or Electrical Activation of Bovine Oocytes on Blastocyst Development and Quality   总被引：2，自引：0，他引：2  

MP Milazzotto  WB Feitosa  ARS Coutinho  MD Goissis  VP Oliveira  MEOA Assumpção  JA Visintin 《Reproduction in domestic animals》2008,43(3):319-322

Activation of in vitro‐matured (IVM) oocytes is essential for successful embryo production following nuclear transfer (NT) or intracytoplasmic sperm injection (ICSI). This study was designed to compare the rates of blastocyst production and embryo quality (as measured by numbers of viable cells) following parthenogenetic activation with electrical pulse or the use of two different calcium ionophores, A23187 (CA) or ionomycin (IO), with or without the addition of bovine serum albumin (BSA). IVM oocytes with a first polar body were randomly allocated to five treatment groups: CA (5 μm CA, 5 min; n = 88), CA + BSA (5 μm CA, 5 min; BSA, 5 min; n = 90), IO (5 μm IO, 5 min; n = 91), IO + BSA (5 μm IO, 5 min; BSA, 5 min; n = 86) and EL (two pulses of 1.5 kV/cm, 20 μs; n = 120). Blastocyst rates were higher (p < 0.05) for CA (54.4%), IO (51.4%) and EL (54.5%) than for IO + BSA (18.3%). Treatment CA + BSA (39.8%) did not differ from the others. There was no difference (p > 0.05) among treatments in total number of cells. However, the percentage of viable cells was reduced in CA (49.9%), CA + BSA (45.8%), IO (64.9%), IO + BSA (50.9%) compared with EL (82.7%). In summary, the addition of BSA to the IO treatment had an adverse effect on blastocyst production rates. Although there was no difference between electrical stimulation and chemical activation on blastocyst production rates, electrical activation resulted in blastocysts with a higher percentage of viable cells.  相似文献   

Evaluation of biomarkers of kidney injury following 4% succinylated gelatin and 6% hydroxyethyl starch 130/0.4 administration in a canine hemorrhagic shock model     

Corrin J. Boyd  Melissa A. Claus  Anthea L. Raisis  Rachel Cianciolo  Erika Bosio  Giselle Hosgood  Mary Nabity  Trevor Mori  Anne Barden  Claire R. Sharp  Lisa Smart 《Journal of Veterinary Emergency and Critical Care》2019,29(2):132-142

Objective : To investigate the association between synthetic colloids and biomarkers of acute kidney injury (AKI) in dogs with hemorrhagic shock. Design : Experimental interventional study. Setting : University. Animals : Twenty‐four healthy ex‐racing Greyhounds. Interventions : Anesthetized Greyhounds subjected to hemorrhage for 60 min were resuscitated with 20 mL/kg of fresh whole blood (FWB), 6% hydroxyethyl starch (HES) 130/0.4, 4% succinylated gelatin (GELO), or 80 mL/kg of isotonic crystalloid (CRYST) over 20 min (n = 6 per treatment). Concentrations of biomarkers of AKI were measured at baseline, end of hemorrhage, and at 40 (T60), 100 (T120), and 160 (T180) min after fluid bolus. Biomarkers included neutrophil gelatinase‐associated lipocalin in urine and serum (uNGAL; sNGAL), and urine cystatin C (uCYSC), kidney injury molecule‐1 (uKIM), clusterin (uCLUST), osteopontin, gamma‐glutamyl transferase, monocyte chemoattractant protein‐1 (uMCP), interleukin‐6, interleukin‐8, protein (uPROT), hyaluronan, and F₂‐isoprostanes. Renal histology was scored for tubular injury and microvesiculation. Biomarker fold‐change from baseline was compared between groups using mixed effects models (Bonferroni–Holm corrected P<0.05). Frequencies of histology scores were compared by Fisher's exact test. Measurements and main results : In dogs treated with GELO, uNGAL fold‐change was markedly greater compared with all other groups at T60, T120, and T180 (all P<0.001), and uCYSC was greater at T60 compared with CRYST (P<0.001), and at T120 and T180 compared with all other groups (all P<0.001). Smaller, albeit significant, between‐group differences in uKIM, uCLUST, uMCP, and urine protein concentration were observed across the FWB, GELO, and HES groups, compared with CRYST. The GELO group more frequently had marked tubular microvesiculation than the other groups (P = 0.015) although tubular injury scores were comparable. Conclusion : In dogs with hemorrhagic shock, GELO was associated with greater magnitude increases in urine biomarkers of AKI and more frequent marked tubular microvesiculation, compared with FWB, CRYST, and HES.  相似文献   

A pilot study of Australian pet owners who engage in social media and their use,experience and views of online pet health information     

LR Kogan  SJ Hazel  JA Oxley 《Australian veterinary journal》2019,97(11):433-439

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