Changes in Plasma Progesterone Levels During Storage of Heparinized Whole Blood from Cow,Horse, Dog and Pig

Progesterone concentrations in heparinized plasma harvested immediately after blood collection were compared with levels obtained after storage of the corresponding whole blood for 2 h, 4 h, 6 h, 1 day, 2 days and 5 days at room temperature and in a refrigerator. The blood was taken during the luteal phase from 4 dogs, 4 horses, 4 pigs and 8 cows. For 4 cows the storage time was extended to 9 and 20 days. No significant effect of whole blood storage time on plasma progesterone concentrations could be shown for dogs or pigs. For the horse a slight but significant decrease was demonstrated when the blood was kept at room temperature. For the cow, however, a dramatic decrease was observed even when the blood was stored in the refrigerator. Following incubation of cow’s blood at room temperature, progesterone levels were close to zero after 1–2 days. By further extending the storage period, a reappearance of assayable progesterone could be elicited. For all species it was found that the storage of plasma at room temperature for 5–9 days did not change the progesterone concentrations.     

The Concentration of Faecal Progestins during the Oestrous Cycle in Nkone Cows and the Effect of Duration of Storage of Faecal Samples at Room Temperature on Faecal Progestin Levels

The objectives of this study were to determine whether ovarian function in Nkone cows could be monitored by measuring progestin concentrations in faeces and to assess the effect of duration of storage at room temperature on faecal progestin concentrations. Faecal and blood samples were obtained once a day for 26 days from 21 Nkone cows whose oestrous cycles had been synchronized. Faecal samples from each cow were divided into five portions that were kept at room temperature for 0, 6, 12, 24 and 48 h, respectively, and then frozen. After centrifuging the blood to recover plasma and extracting steroids from the faeces, analysis of progesterone (P₄) was carried out using solid-phase radioimmunoassay. The faecal progestin and plasma progesterone profiles corresponded well and were positively correlated (r = 0.70, p>0.01). Faecal progestin concentrations decreased with increasing duration of storage at room temperature during both the follicular and luteal phases (p>0.01). In both cases, the decline in faecal progestin concentrations followed an exponential pattern. The progestin concentrations in faeces after 48 h of storage at room temperature were higher (p>0.05) during the peak luteal phase than in the follicular phase.     

Effects of storage time on chemistry results from canine whole blood,heparinized whole blood,serum and heparinized plasma

The stability and storage characteristics of 24 blood constituents from dogs including nine enzymes (ALP, ALT, amylase, AST, CK, GGT, GLDH, LDH, lipase), 15 metabolites and minerals (albumin, bile acids, bilirubin, calcium, cholesterol, creatinine, fructosamine, glucose, magnesium, phosphate, potassium, protein, sodium, triglycerides, urea) were studied. Conditions studied included storing of nonanticoagulated and heparinized whole blood for 3 days (Part A), and storing of serum and heparinized plasma for 3 days (Part B). The storage temperature for both studies was +4 degrees C from day 0 to day 1, and +20 degrees C, from day 1 to day 2 and 3. Eight of 24 analytes showed no significant differences (p > 0.05) for three days in whole blood. However, the stability of all 24 analytes greatly improved by storing serum or heparinized plasma compared to nonanticoagulated or heparinized whole blood. In stored serum or heparinized plasma, 20 of 24 analytes showed no significant differences (p < 0.05) for 3 days. Nine of 24 analytes showed significant differences (p < 0.05) between serum and heparinized plasma, where CK, LDH, GGT, and potassium showed differences of possible clinical importance. This study strongly supports the practice of separating serum/plasma from clot/cells as promptly as possible to achieve improved stability for most analytes under test.     

Effect of storage on some constituents of camel serum

SUMMARY Effects of storage at room temperature (23–25°C) and refrigeration (4–5°C) on various biochemical constituents of camel serum were investigated. Albumin, globulin, calcium, phosphorus, cholesterol, aspartate aminotransferase (AST), alkaline phosphatase (AP) and gamma glutamyltransferase (GGT) did not change over 9 days when stored at 4–5°C. At 4–5°C, creatinine, iron and glucose in camel sera remained stable for 6 days; total protein for 7 days; and blood urea nitrogen for 8 days. Decreased activities in creatine kinase (CK), lactate dehydrogenase (LDH) and alanine aminotransferase (ALT) were apparent after 1, 6 and 7 days, respectively. At room temperature, total protein, albumin, globulin, calcium and phosphorus were stable throughout the 9 days. Changes in glucose and iron occurred after 3 days. Stability at room temperature for LDH was 1 day; AST, 3 days; GGT and ALT, 6 days; and AP, 8 days. CK activity had already declined by 4 hours and by 9 days, only 34% activity remained.     

Sample handling substantially affects Johne's ELISA

Detection methods for Mycobacterium avium subsp. paratuberculosis (MAP) are imperfect, yet crucial for diagnosis of Johne's disease. Our purpose was to test for significant and biologically relevant changes in Johne's ELISA results associated with how field-collected blood samples were transported to the laboratory, prepared and stored prior to testing, while removing potential confounding by test kit and laboratory variables. Blood samples were collected from 21 cows that previously had MAP ELISA scores ranging from negative to highly positive. Samples for immediate laboratory processing were subjected to different transportation temperatures (on ice, 26 °C) and preparation methods (serum separated, hemolyzed and serum separated, clotted whole blood), but were tested using the same ELISA kit in the same laboratory. Samples for laboratory processing after one week of storage were subjected to different storage temperatures (4 °C, −20 °C) and preparation methods (serum separated, hemolyzed and serum separated, clotted whole blood), and again were tested using the same ELISA kit in the same laboratory. Finally, samples were evaluated by time to processing (one day, one week) and storage temperature (4 °C, −20 °C). Data were checked for normality and analyzed with repeated measures ANOVAs. Significantly (P = 0.027) higher MAP ELISA scores were recorded for whole blood and hemolyzed samples transported at 26 °C than serum separated samples. Sample storage for one week at −20 °C resulted in significantly (P < 0.001) lower MAP ELISA scores, regardless of handling method, compared to samples stored at 4 °C for one week. Method of sample preparation, as well as transportation temperature and medium-term storage temperature, affects MAP ELISA results. Such discrepancies will inevitably result in improper classification of MAP-infected cattle, impeding both biosecurity measures on uninfected farms and MAP control programs.     

Changes of platelet function and blood coagulation during short-term storage of CPDA-1-stabilised ovine blood

The objective of this study was to detect the influence of short-term storage on the haemostatic function in whole citrated ovine blood at different storage temperatures. Ovine blood was collected in a commercial transfer bag system containing CPDA-1 and stored on a wobbler at room (20-25 °C; n = 5) or refrigerator temperature (4 °C; n = 5). The following analyses were performed initially and after 1, 2, 3, 4, 5, 6, 8, 12, 24, 48 and 72 h of storage: platelet count and (spontaneous) aggregates, agonist-induced platelet aggregation with two methods (impedance aggregometry, turbidimetric method), prothrombin time, activated partial thromboplastin time, thrombin time, fibrinogen concentration and resonance thrombography.Platelet count remained stable at room temperature, whereas a significant decrease was detected after 48 h storage at 4 °C. The latter was associated with the formation of a high percentage of platelet aggregates (50-60%) after 5 h storage. Decrease in platelet aggregation was significantly more pronounced when blood was stored at 4 °C. The plasmatic coagulation tests were stable within the observation period.Results indicate that platelet count and aggregability of CPDA-1-stabilised ovine blood is better preserved at room temperature and provides adequate haemostatic function for ex vivo experiments for one working day. Functional loss and high percentage of platelets within aggregates which were observed in ovine blood stored at refrigerator temperature have to be considered in blood transfusion in sheep.     

Stability of common biochemistry analytes in equine blood stored at room temperature

Reasons for performing study: Time delays between collection of blood samples and biochemical analysis of equine blood are unavoidably common in equine practice. The effect that delays may have on the accuracy of results of blood biochemical analyses is not well established. Hypothesis: Delays in processing of blood of up to 72h results in alterations in measured levels of common biochemical analytes that are of potential clinical relevance. Separation of serum prior to storage is protective against the effects of time delays. Methods: Samples of clotted blood, separated serum and oxalate fluoride plasma from 20 horses were stored and analysed at 0, 24, 48 and 72 h. Graphical exploration of each analyte was undertaken. General linear models with fixed effects were fitted for the whole blood data. The mean bias and 95% limits of agreement were calculated, using bootstrapped data, to assess agreement between pairs of samples analysed at 0 h and other time points. Bland‐Altman plots were used to explore general trends in the data. Paired t tests were used to compare the results from whole blood and separated serum. Results: Delays in processing equine blood resulted in significant increases in measured concentrations of aspartate aminotransferase, creatine kinase, lactate dehydrogenase, total bile acids and magnesium. A significant decrease in concentration was identified for glucose (serum and oxalate fluoride preserved plasma). Separation of serum immediately following clot formation resulted in nonsignificant increases in accuracy for some analytes. Conclusions and practical significance: Delays in processing of blood samples may result in biochemical changes of clinical relevance in individual cases; however, in the majority of cases, where delays are only a few days and a number of analytes are assessed concurrently, delays are unlikely to have an effect on the interpretation of results. Separation of serum following clot formation is of limited benefit. Clinical samples in which a delay in processing has occurred may be interpreted with reference to the data presented.     

Effects of syringe material and temperature and duration of storage on the stability of equine arterial blood gas variables

OBJECTIVES: To evaluate the consistency of partial pressures (P) of arterial oxygen (aO(2)), arterial carbon dioxide (aCO(2)) and pH measurements in equine carotid arterial blood samples taken into syringes made from three different materials and stored at room temperature or placed in iced water for measurement at three different times. STUDY DESIGN: Prospective observational study over 19 days. ANIMALS: Four clinically normal Thoroughbred or Thoroughbred-cross horses (three geldings, one mare, mean age 6.25 years, range 5-7 years). METHODS: Identical blood samples were taken on two separate occasions from the carotid arteries of the four horses into syringes made of glass, plastic and polypropylene. PaO(2), PaCO(2) and pH determinations were performed on blood from each syringe type at 10, 60 and 120 minutes post-sampling with samples stored at room temperature (approximately 20 degrees C) or in iced water (approximately 0 degrees C). Data were analysed by anova and a split plot model fitting syringe within horse X pair and time within temperature within syringe. RESULTS: Syringe material, storage temperature and time before analysis all had significant effects on PaO(2) (p < 0.001). PaCO(2) was unaffected by syringe material or storage temperature. However, over 120 minutes, storage duration significantly (p = 0.002) affected values. Temperature of storage and duration prior to analysis both significantly affected pH values (p = 0.005 and p < 0.001, respectively), but syringe material did not. Several significant interactions between these variables were noted. CONCLUSIONS: Equine arterial blood gas determination has a different sensitivity to storage conditions compared to other veterinary species. CLINICAL RELEVANCE: For accurate equine arterial blood analysis, PaO(2) samples need to be analysed within 10 minutes or taken into glass syringes, stored on ice and analysed at 2 hours post-sampling. PaCO(2) and pH measurements can be performed on samples stored in glass, plastic or polypropylene syringes at room temperature for up to 1 hour post-sampling.     

Effects of storage times and temperatures on T3, T4, LH, prolactin, insulin, cortisol and progesterone concentrations in blood samples from cows

Little is known about stability of hormones in blood samples stored under various conditions. This study was conducted to examine stability of triiodothyronine (T3), thyroxine (T4), luteinizing hormone (LH), prolactin, insulin, cortisol and progesterone in blood and serum samples. Experiment 1 was designed to determine if concentrations of these hormones were affected by exposure to cellular elements of anticoagulated and coagulated blood when stored at 4 C and room temperature (22 to 26 C). Jugular venous blood was collected from six diestrous Holstein cows into evacuated bottles containing sodium ethylenediaminetetraacetic acid (EDTA), heparin or no anticoagulant. Subsamples of EDTA-treated and heparinized blood were stored .25, .5, 1, 2, 4, 8, 24 and 72 h at 4 C or room temperature. Subsamples of blood without anticoagulant were stored in polypropylene tubes (clot tubes) or serum separator tubes for 1, 2, 4, 8, 24 ad 72 h. Mean concentrations of T3, T4, LH, prolactin and cortisol did not change in plasma or serum from either of the four types of samples stored at 4 C or room temperature for 72 h. The mean insulin concentration decreased 18% by 72 h in serum from serum separator tubes stored at room temperature. At 4 C, mean progesterone concentrations decreased 55% by 24 h and 73% by 72 h in plasma from EDTA-treated blood; 41% by 72 h in serum from clot tubes, and 26% by 24 h and 36% by 72 h in serum from serum separator tubes.(ABSTRACT TRUNCATED AT 250 WORDS)     

Developmental competence of cat oocytes from ovaries stored at various temperature for 24 h

We conducted two experiments to investigate the effects of storage temperature and period for cat ovaries on the meiotic and developmental competence of oocytes collected from the ovaries. In Experiment 1, ovaries were stored in physiological saline for 24 h at 4 C, 23-25 C, or 38 C (cold, room, and incubator temperature groups, respectively), and then oocytes were collected from the ovaries in each group. Morphologically intact oocytes were then selected and cultured in maturation medium for 24 h. Significantly more oocytes reached metaphase II (MII) in the cold temperature group (53.4%) than in the room and incubator temperature groups (20.0 and 2.4%, respectively). In Experiment 2, ovaries were stored in physiological saline at room temperature for 0, 6, 12 or 18 h, and then they were stored at 4 C (cold storage) until reaching a total storage period of 24 h. After storage of the ovaries, morphologically intact oocytes were matured, fertilized with frozen-thawed spermatozoa, and cultured in vitro. The rates of morphologically intact oocytes obtained from the ovaries stored at room temperature for 0, 6, 12 or 18 h were 35.3, 30.0, 26.4 and 14.7%, respectively, and the rates of intact oocytes that reached MII were 63.2, 36.4, 26.5 and 11.9%, respectively. The results suggested that the numbers of morphologically intact oocytes and intact oocytes that reached MII after in vitro maturation decrease gradually as the period of storage at room temperature before cold storage increases. Only oocytes from ovaries stored for 6 h developed to the blastocyst stage after in vitro maturation and fertilization when ovaries were stored at room temperature before cold storage. These results indicate that 24 h storage of ovaries at high temperatures (>23 C) decreases the meiotic competence of oocytes. The quality and developmental competence of oocytes are influenced by the length of storage at room temperature before cold storage.     

Changes in canine ionised calcium under three storage conditions

OBJECTIVES: To determine the ionised calcium concentration following aerobic collection of blood and to compare ionised calcium concentration and pH of heparinised whole blood and plasma at 48 hours following collection under three different storage conditions to assess if ionised calcium concentration can be measured retrospectively. METHODS: Blood was collected from 17 dogs for analysis of ionised calcium concentration and pH using a Rapidpoint 400 (Bayer) blood gas analyser. Blood was collected into a commercial preheparinised syringe and into a plain syringe, with subsequent transfer to a commercially available heparinised sample tube. Samples were analysed within 10 minutes, and the remainder was divided for storage. One aliquot was set-aside at room temperature for 48 hours, and the other was immediately centrifuged and the plasma divided for storage at room temperature and at 4 degrees C for 48 hours each. In all samples, ionised calcium concentration and pH were measured again at 48 hours after storage. RESULTS: There was no significant difference in ionised calcium concentration or pH between anaerobically and aerobically collected heparinised whole blood analysed within 10 minutes of collection. At 48 hours, ionised calcium concentrations had decreased under all storage conditions irrespective of the direction of pH change. CLINICAL SIGNIFICANCE: Ionised calcium concentration can be measured in aerobically collected samples within 10 minutes and at 48 hours after collection under the conditions described.     

Effect of storage on microcytosis observed in dogs with portosystemic vascular anomalies

Microcytosis is a common laboratory finding in dogs with iron deficiency and congenital portosystemic vascular anomalies (PSVA), however artefactual changes due to blood storage may occur which could mask this feature. This study evaluated the effects of storage on microcytosis in dogs with congenital PSVA. Full haematological parameters were measured on the day of sampling and following 24h storage at room temperature, in unaffected dogs (n=13) and in dogs affected with PSVA (n=24). Storage for 24h resulted in significantly higher MCV values in both groups of dogs (P<0.01). The percentage increase in MCV was greater in the control dogs (median 8.07%, range 5.64-9.31%) compared to affected dogs (median 6.05%, range 3.12-15.21%) (P<0.02). Storage of 1ml EDTA blood samples at ambient temperature for 24h prior to analysis, as occurs when samples are posted to external laboratories, will have significant effects on MCV and may mask microcytosis in dogs with PSVA.     

Relationship between separation time of plasma from heparinized whole blood on plasma biochemical analytes of loggerhead sea turtles (Caretta caretta)

Concentrations and activities of selected biochemicals of loggerhead sea turtles (Caretta caretta) were determined for plasma that was separated from whole blood samples that were kept up to 96 hr post collection (PC) in a refrigerator. Blood samples collected from seven juvenile captive loggerhead sea turtles were added to tubes containing lithium heparin and were placed on ice. Equal amounts of anticoagulated whole blood from the lithium heparin tubes were then aliquoted into plastic tubes and stored as whole blood under refrigeration until they were centrifuged at 0, 4, 24, 48, and 96 hr PC. Plasma was removed and the analytes that were measured were alkaline phosphatase (ALP), aspartate aminotransferase (AST), gamma glutamyl transferase (GGT), creatine kinase (CK), sodium, chloride, potassium, magnesium, calcium, phosphorus, cholesterol, glucose, urea nitrogen, uric acid, total protein, albumin, and globulin. Compared with values at 0 time, the only analyte to be significantly different at 24 hr PC was GGT (activity decreased by 25%). Compared with values at 0 time, significant differences at 96 hr PC were only seen in AST (2% increase), GGT (25% decrease), glucose (7% decrease), and uric acid (25% increase). Although a statistically significant difference was found in concentrations of phosphorus and cholesterol over time by repeated measures analysis of variance (ANOVA), the follow-up multiple comparison procedure could not define the specific time points at which significant differences occurred. For all other analytes, significant differences over the time course of the study were not found. In these instances, the power of the ANOVA was sufficient (> or = 0.80) to detect any arithmetic differences of a clinically relevant magnitude. Although plasma should be separated from the cellular component of blood as soon as possible PC, in a field situation in which a centrifuge is unavailable, samples can be stored in a portable cooler up to 24 hr without appreciable change in select biochemical analytes.     

Effects of different variables on whole blood cholinesterase analysis in dogs.

The influence of several variables such as sample and reagent storage, anticoagulants, reaction temperature, pH, and substrate concentration on whole blood cholinesterase determination was studied. Storage of nondiluted whole blood samples at room temperature or under refrigeration (4 C) was adequate for short-term storage (3 days to 2 weeks). However, freezing would be more appropriate for long-term storage (> or = 1 month), and successive thawing and freezing did not produce any loss of cholinesterase activity. All reagents (2,2'-dithiodipyridine as chromophore and acetylthiocholine and butyrylthiocholine as substrates) were stable for 3 months when frozen. Heparin and ethylenediaminetetraacetic acid were the most suitable anticoagulants for whole blood acetylcholinesterase and butyrylcholinesterase determination, because citrate yielded lower acetylcholinesterase values and fluoride inhibited butyrylcholinesterase. Increases in reaction temperature and pH yielded higher cholinesterase values but also increased nonenzymatic substrate hydrolysis. Higher cholinesterase and nonenzymatic substrate hydrolysis values were obtained as higher substrate concentrations were used.     

Effect of Different Storage Conditions on Platelet Aggregation in Horse

Platelet aggregation is the most important event in the hemostatic process, but no information is available on the stability of samples for aggregation testing in horses. The aim of the present study was to evaluate the effect of different storage conditions on platelet aggregation in horses. The study was carried out on 58 healthy horses of varying breed and gender, ranging in age from 4 to 12 years. Citrated blood samples were collected from all the subjects by means of jugular venipuncture and were used for platelet aggregation measurements. Platelet-rich and platelet-poor plasma samples were prepared by centrifugation and divided into six different aliquots to assess the maximum degree of platelet aggregation and the initial velocity of platelet aggregation at the final concentrations of 1 and 0.5 μM of the aggregating agent. The first aliquot was analyzed within 1 hour after collection at room temperature (22°C), the second 6 hours after collection at 22°C, the third and fourth were refrigerated at 8°C for 6 and 24 hours, respectively, and the fifth and sixth were frozen at −20°C for 24 and 48 hours, respectively. With the help of an aggregometer, platelet responses were quantified, and one-way repeated measures analysis of variance was used to determine significant differences. Probability values of <.05 were considered to be statistically significant. Analysis of variance showed statistically significant differences on maximum degree of platelet aggregation and the initial velocity of platelet aggregation using adenosine diphosphate at final concentrations of 1 and 0.5 μM. The results of this study suggest that the storage of equine plasma for more than 6 hours at room temperature and at 8°C has a significant effect on platelet aggregation, and that the storage of plasma for 24 and 48 hours at −20°C alters platelet aggregation. In conclusion, storage conditions had a statistically significant effect on the parameters of platelet aggregation directly correlated to temperature.     

Effects of road type during transport on lamb welfare and meat quality in dry hot climates

This study determined whether transporting lambs on paved (PR) or unpaved roads (UR) for 3 h had an effect on plasma stress indicators (cortisol, lactate, glucose, creatine kinase [CK], red blood cells, white blood cells, hematocrit, and neutrophil/lymphocyte [N/L] ratio) and instrumental meat quality (pH24, bruising score, water holding capacity [WHC], color, and texture). A total of 48 Rasa Aragonesa male lambs were used that were approximately 100 days old (12.5 kg ± 1.64, carcass weight). The results suggest that transport on unpaved roads had a significant influence on physiological and hematological stress parameters. Road type had a significant effect on all variables, except for white and red blood cells, and hematocrit levels. The UR lambs had significantly higher (at least p ≤ 0.01) cortisol, lactate, glucose, and CK levels and a higher N/L ratio than PR lambs. Meat from UR lambs had some dark-cutting characteristics, with a darker color, higher ultimate pH, and higher tenderness values than PR. In conclusion, lambs transported on unpaved roads had a more intense stress response and poorer meat quality than lambs transported on paved roads. An effort to improve the logistics associated with route planning is necessary to prevent welfare problems during transport to slaughter.     

Effects of storage time and freezing temperature on clinical chemical parameters from canine serum and heparinized plasma

To assess changes in 24 blood constituents in frozen serum and heparinized plasma, blood samples were drawn from 10 clinically normal German Shepherd army dogs. The storage characteristics of nine enzymes (ALP, ALT, amylase, AST, CK, GGT, GLDH, LDH, lipase), and 15 metabolites and minerals (albumin, bile acids, bilirubin, calcium, cholesterol, creatinine, fructosamine, glucose, magnesium, phosphate, potassium, protein, sodium, triglycerides, urea) were studied. Parallel samples of serum and heparinized plasma were stored for 90 and 240 days at two different storage temperatures, -200 degrees C and -700 degrees C. Sixteen of the 24 analytes (ALP, ALT, amylase, AST, CK, GGT, GLDH, LDH, bile acids, calcium, cholesterol, creatinine, fructosamine, magnesium, phosphate, urea) showed statistically significant (p < 0.05) changes during the storage period related to storage time, storage temperature, and sample type. Seven of the analytes (amylase, GGT, GLDH, LDH, bile acids, fructosamine, magnesium) showed changes of possible clinical importance with mean differences from baseline larger than 20% for the enzymes and 10% for the metabolites and minerals during the storage periods.     

Metabolic and clinical traits in horses undergoing feed deprivation for elective orthopaedic surgery

The objective of this study was to investigate some metabolic and clinical effects of feed deprivation in horses that were submitted for orthopaedic surgery. The effects of preoperative feed restriction were investigated in 20 horses submitted for elective orthopaedic surgery.The patients were fasted from 12 hours before until 4 hours after surgery. Serum free amino acids, glucose,free fatty acids (FFA), white blood cell counts, creatine kinase (CK) and aspartate aminotransferase (AST) were determined 24 hours before surgery, 2 hours after the end of anaesthesia and 24 and 72 hours after surgery. Besides, abdominal sounds, appetite, faecal quality and body temperature were examined. Serum free amino acids did not react homogenously, concentrations were partly increasing or decreasing. Plasma glucose and FFA increased after surgery and returned to their preoperative levels 72 hours after surgery. A significant rise of the segmented granulocytes occurred 24 hours after surgery, all other parameters of the leukogram did not exceed the physiological range. AST reached its highest activity 24 hours after surgery, whereas CK activities were highest at 2 hours after surgery. Abdominal sounds were significantly reduced until 24 hours after surgery, however, appetite was not depressed. Faecal quality was physiological after surgery. Mean body temperature stayed within the physiological range. In conclusion, a relatively short perioperative fasting period had significant effects on the metabolic traits in horses, however the effects on physiological functions were minor. The consequences of major surgical procedures need to be addressed in future studies.     

禁食、急性冷暴露和外源性注射Ghrelin对羔羊生理指标的影响

为了探究禁食、急性冷暴露和注射外源性生长激素释放肽Ghrelin对羔羊生理指标的影响,本研究监测了室温禁食24h后继续禁食并冷冻(-24.7℃±0.2℃)2h羔羊基本生命体征、血液生理指标和血糖浓度的变化,同时探究了外源性Ghrelin对于冷冻的禁食羔羊以上指标的影响。结果显示,在禁食后8、16、24h羔羊呼吸频率、心率和血糖浓度均较禁食前显著降低(P0.05),在禁食后16h和24h直肠温度均较禁食前极显著降低(P0.01),而血液生理指标变化不明显(P0.05);在冷冻1.5h和2.0h后羔羊呼吸频率较保温组显著减慢(P0.05),心率和血糖浓度在冷冻后1.0、1.5、2.0h显著增加(P0.05),冷冻过程中羔羊直肠温度差异不显著(P0.05);冷冻2h后颈静脉一次性注射Ghrelin未发现对羔羊以上指标的影响(P0.05)。以上研究结果提示,羔羊在禁食和低温情况下可通过调整自身活动,以维持机体稳态,并且Ghrelin可能并未参与该调整过程。     

Plasma aspartate aminotransferase and creatine kinaseactivities in thoroughbred racehorses in relation to age, sex, exercise and training

In order to investigate the effect of age, sex and month on the response of plasma aspartate aminotransferase(AST) and creatine kinase (CK) to exercise, blood samples were collected once a month between March and September from a group of 40 2- and 3-year-old (2yo and 3yo) thoroughbred racehorses (kept under the same managemental regimen) at rest before exercise (PRE) and at 2 (2H) and 24h (24H) post-exercise. The absolute change in activities between the 2H and PRE samples (2HΔ) and the 24H and PRE samples (24HΔ) was also calculated. Age had a significant effect on all measured and calculated parameters for colts (C), apart from 24HΔ CK but showed no effect in the fillies (F). Sex only had a significant effect in the 3yo in the 2HΔ CK. In the 2yo, significant effects of sex were found for both CK and AST in the PRE, 2H and 24H samples. The effect of month varied according to the classification group with only the 2yoC not showing any significant effect on any parameter. Fillies were, in general, more likely than colts to show greater than a twofold increase in CK activity at 2H post-exercise and the number of animals showing such an increase decreased as the season progressed. Very little change in AST activities occurred with exercise.