硫酸阿米卡星在犬体内的药代动力学

选择8只健康成年的试验犬,按照10 mg·kg-1的剂量单剂量对所有试验犬皮下注射阿米卡星注射液,并于注射阿米卡星之后的不同时间点采集血液样品,按照本试验选用的方法对采集的血液样品进行处理,测定血浆中阿米卡星的浓度,并运用3P97药物软件将所得到的阿米卡星的药-时曲线进行分析。结果表明:在0.5¹00μg·mL-1的浓度范围内,阿米卡星在血浆内的药物浓度与峰面积呈现良好的线性关系,其线性方程为y=10 008x+24 570,R2=0.997。在本试验选用的条件下,犬单剂量皮下注射阿米卡星后的药-时曲线符合一级吸收二室开放模型,其主要的药代动力学参数包括:达峰时间(Tmax)为(0.886±0.06)h,峰浓度(Cmax)为(31.35±1.41)μg·L-1,血浆中药物的消除半衰期(T1/2β)为(1.779±0.13)h,药时曲线下面积(AUC)达到(104.9±8.46)μg·h·L-1。结果表明:犬皮下注射阿米卡星后,其在体内分布广泛,且消除时间短。本试验的分析方法准确、灵敏、重现性好,所选用的测定血浆内阿米卡星浓度的方法能满足对阿米卡星临床效果的评价要求。     

蚕沙发酵肥对连作延胡索产量和品质的影响

为了拓宽蚕沙发酵肥在农业生产领域的应用范围,通过盆栽试验,用连作2年的延胡索土壤为栽培基质,以不同施用量的蚕沙发酵肥为处理方式,研究蚕沙发酵肥对连作延胡索产量和品质的影响。结果表明,与连作相比,外源施用不同剂量的蚕沙发酵肥均能不同程度地提高连作延胡索产量,以及地下块茎内的生物碱和核苷含量及其产量,随着蚕沙发酵肥施用量的增加,上述指标呈现先升高后降低的趋势,其中,施用4.5 g/kg蚕沙发酵肥的调控效果最佳。可见,在延胡索连作条件下增施蚕沙发酵肥可以有效地延缓延胡索的连作障碍,维持延胡索产量和品质的稳定性。     

山楂叶提取物对犬心脏动力学的影响

山楂为蔷薇科植物, 在我国具有悠久的保健与药用历史.过去人们只注重其果实方面的效果,但近几年随着提取工艺、检验手段的提高, 对于山楂叶的研究有了很大促进, 尤其是其在心血管系统方面有效的治疗保健作用以及抗衰老等作用, 使之更加受到人们的青睐[1].     

2种头孢氨苄片在比格犬体内的药代动力学及生物等效性试验

【目的】研究头孢氨苄片受试制剂和参比制剂在比格犬体内的生物等效性。【方法】采用双周期和双序列交叉设计,将22只健康比格犬随机分成2组,按30 mg/kg BW分别单剂量口服头孢氨苄片受试制剂Trolevis~?300和参比制剂Rilexine~?300,于给药前(0 h)和给药后0.5、1、1.5、2、2.5、3、4、6、8、12、17和24 h从臂头静脉采血。对超高效液相色谱串联质谱(UPLC-MS/MS)方法进行特异性、线性、检测限、准确度、精密度、稳定性等方法学考察。利用建立好的UPLC-MS/MS方法测定血浆中的药物浓度,并用WinNonlin^TM 8.1软件对药代动力学参数进行分析计算。【结果】方法学结果显示,在100～5 000 ng/mL浓度范围内相关性良好,相关系数(R²)≥0.99,标准曲线方程为y=10.6828x-176.481;高、中、低3个浓度的相对回收率平均值分别为105.63%、104.35%和102.40%;日内和日间变异系数均<15%;检测限为50 ng/mL,定量限为100 ng/mL。药代动力学结果...     

多拉菌素浇泼剂在犬体内的药代动力学

本试验对多拉菌素浇泼剂在犬血浆中的药代动力学进行了研究。犬背部皮肤一次浇注多拉菌素浇泼剂(0.1 mg/kg体重),给药后,不同时间点从犬前肢静脉采血。以高效液相色谱法对血浆中药物浓度进行测定,血浆药物浓度—时间数据用WinNonlin 5.2.1的非房室模型药动软件处理。给药后的主要药物动力学参数为:t1/2β为(2.14±0.56)d,T_max为(1.00±0.00) d,C_max为(24.38±4.82) ng/mL,AUC为(89.79±16.90)ng/(d·mL)。提示多拉菌素浇泼剂在犬体内血药浓度维持的时间较长,消除缓慢。     

丙磺舒对阿莫西林在猪体内的药代动力学影响

本实验采用高效液相色谱法测定猪血浆中阿莫西林的浓度,研究了丙磺舒对阿莫西林在健康猪体内药物动力学的影响。结果表明,单剂量肌肉注射阿莫西林后,阿莫西林吸收迅速,药峰时间为(0.19±0.11)h,药物浓度为(7.21±3.27)μg/mL,其动力学模型为一级速率一室模型。使用丙磺舒后,阿莫西林的半衰期由(0.86±0.18)h延长到(2.77±1.02)h(P<0.05),AUC由(12.38±5.69)μg/mL·h增加至(35.24±18.62)μg/mL·h,药峰时间为(0.42±0.32)h,药峰浓度为(6.24±3.43)μg/mL·h。     

异氟烷对MIRI老年犬血流动力学影响的研究

为了探讨异氟烷对老年犬心肌缺血再灌注损伤(myocardium ischemia reperfusion injury, MIRI)时血流动力学的影响,试验用20只健康老年比格犬建立MIRI模型,将试验犬随机分为对照组和异氟烷组,两组犬按体重30 mg/kg于前肢静脉注射戊巴比妥钠注射液。对照组犬以每隔1 h按体重2 mg/kg额外静脉注射戊巴比妥钠注射液进行维持麻醉,异氟烷组犬用全自动呼吸麻醉机吸入2%异氟烷进行维持麻醉,两组犬都以60 mL/h的速度于股静脉注射生理盐水以弥补体液流失。开胸阻断左冠状动脉前降支(LAD)血液90 min后再灌注200 min,于阻断前(给药前、给药后60分钟)、阻断后90分钟及再灌注60,120,180分钟时,分别检测心率(HR)、肺动脉压(PAP)、肺动脉楔压(PCWP)、中心静脉压(CVP)、平均动脉压(MAP)。结果表明：与阻断前比较,阻断后90分钟及再灌注60,120,180分钟对照组老年犬HR显著升高(P<0.05);各时间点异氟烷组老年犬HR均低于对照组,其中在阻断后90分钟及再灌注60,120,180分钟时两组间差异显著(P<...     

麻醉对犬血液流变学的影响

关于麻醉对血液流变学的影响是近年来医学研究的热点,不同麻醉方式和麻醉药可改变血液流变性质,对手术和预后有一定的影响。吸入麻醉时,吸入麻醉药和高浓度氧气可降低红细胞聚集性和变形性,增加血液中纤维蛋白原降解,减少红细胞桥形成,降低血黏度。硬膜外阻滞麻醉时,局麻药可引起阻滞区域血管扩张、血管阻力减小、血流加快,使红细胞聚集性及血沉方程K值降低,降低血浆及全血黏度、改善术后的纤溶抑制状态;降低血小板浓度,但不抑制血小板聚集作用。此外,麻醉药除了对神经系统作用外,还对内分泌及细血管系统有明显的作用,引起血管的收缩或扩张,导致血液流变性质的变化。     

中药复方制剂“宠康”的药代动力学研究

选择给药后血清中超氧化物歧化酶(SOD)活力升高率为药效学指标,对动物保健中药复方制剂“宠康”进行了药代动力学研究。量-效关系研究表明,在一定的给药剂量范围内,“宠康”对血清中SOD活力的升高率呈现一定的量效相关;通过时-效关系,研究了“宠康”在小鼠体内的药代动力学特征。     

利多卡因、布吡卡因行犬硬膜外阻滞时的药代动力学

为研究利多卡因(lidocaine)和布吡卡因(bupivacaine)行硬膜外阻滞时的药代动力学特征,将16只健康犬随机分成2组(n=8),硬膜外阻滞时按体质量分别注入2%利多卡因6mg/kg和0.5%布吡卡因2mg/kg,在注药后的3、5、8、10、15、20、30、40、50、60、75、90、120、150、180min分别采取股动脉血,用气相色谱法测定血药浓度,比较2组药代动力学指标。结果表明,利多卡因和布吡卡因的药-时曲线均符合一室开放模型,t1/2ka分别为(3.55±0.73)min和(7.76±0.38)min,tpeak分别为(18.8±2.2)min和(35.6±1.5)min,Cmax分别为(4.67±0.37)mg/L和(1.38±0.08)mg/L,AUC分别为(739±73)μg.mL-1.min和(366±45)μg.mL-1.min,CL分别为(12.2±4.6)mL/min和(5.5±0.67)mL/min。     

Effects of thoracolumbar epidural anesthesia with lidocaine on the systemic hemodynamics and hepatic blood flow in propofol anesthetized dogs

General anesthesia reduces hepatic blood flow (HBF) from circulatory depression. Total intravenous anesthesia (TIVA) is associated with decreased circulatory depression compared to inhalation anesthesia, and epidural anesthesia using local anesthetics increases blood flow by blocking the sympathetic nerves and expanding blood vessels. We investigated the effects of thoracolumbar epidural anesthesia with TIVA on HBF in dogs. Six Beagle dogs had epidural catheters placed between T13 and L1 and were anesthetized with propofol and vecuronium. Physiological saline (control) or 2% lidocaine (0.2 ml/kg, followed by 0.2 ml/kg/hr) was administered at 1–2 weeks intervals. Heart rate (HR), cardiac index (CI), mean arterial pressure (MAP), and systemic vascular resistance index (SVRI) were recorded at 10-min intervals from before epidural injections (T0) to 110 min. Indocyanine green test was used to measure HBF during the awake state and until 90 min after epidural injections. HR and CI did not differ between treatments. MAP and SVRI after lidocaine were significantly lower than those of controls, and the lowest MAP value was 65 ± 11 mmHg at T10. Compared to T0, after lidocaine treatment, HBF was significantly higher at T30, T60 and T90 (P<0.05); while, after control treatment, no significant change was evident at any time point. Despite a decrease in MAP by this technique, HBF was either maintained at pre-anesthetic levels or increased in comparison to controls, probably due to vasodilation of the hepatic artery induced by the selective blockade sympathetic ganglia.     

Indirect measurement of blood pressure using a pulse oximeter in isoflurane anesthetized dogs

Objective: To determine the accuracy of indirect blood pressure (BP) measurements obtained with a pulse oximeter as compared with direct measurements in dogs under isoflurane anesthesia. The Doppler and oscillometric BP monitors were included for comparison. Design: Prospective, experimental study. Animals: Twenty healthy dogs (23 ± 8 kg) anesthetized for research or teaching. Interventions: Dogs were anesthetized with propofol or thiopental and maintained using positive pressure ventilation with isoflurane in 100% O₂. Random adjustment of BP was achieved by inhalant adjustment or dopamine infusion to achieve low (≤85 mmHg), normal (90–120 mmHg), or high systolic BP (≥125 mmHg). Triplicate measurements for BP were taken with direct (dorsal pedal artery), Doppler (forelimb), oscillometric (same forelimb), and plethysmographic (pulse oximeter on tongue) methods. Measurements and main results: Using regression analysis and a modified Bland–Altman's technique, the lowest bias was achieved with the Doppler. Systolic BP readings at low, normal, and high BP were within 10 mmHg of direct recordings 95%, 70%, and 30% of the time for pulse oximetry; 95%, 85%, and 55% of the time for Doppler; 42%, 65%, and 30% of the time for oscillometric determination, respectively. Oscillometric mean BP readings were within 10 mmHg of direct measurements 53%, 60%, and 45% of the time, respectively. Conclusions: The pulse oximeter is an acceptable method for measuring BP in anesthetized dogs if assessment of trends is sufficient. All indirect methods showed greater bias and poorer precision at high BP. The Doppler may be the preferred indirect method.     

Effects of dopamine, dobutamine, amrinone and milrinone on regional blood flow in isoflurane anesthetized dogs

The effects of cyclic AMP increasing cardiotonics (dopamine, dobutamine, amrinone and milrinone) on the blood flow in most organs were compared using colored microsphere technique in isoflurane-anesthetized dogs. Dopamine increased blood flow in ventricular myocardium. Furthermore dopamine induced the increase in blood flow in intestine and kidney at low to middle dose, but not at high dose. Dobutamine induced the highest increase in blood flow in ventricular myocardium and skeletal muscle among the drugs evaluated at middle and high doses. Amrinone and milrinone increased blood flow in ventricular myocardium almost same with catecholamines, and milrinone decreased vascular resistance moderately in most other organs. Milrinone might be more useful than catecholamines for improvement of congestive heart failure or peripheral circulatory failure accompanied with exceeded vasoconstriction.     

Evaluation of an indirect oscillometric blood pressure monitor in normotensive and hypotensive anesthetized dogs

Objective – To determine the accuracy and precision of an oscillometric noninvasive blood pressure device as a predictor of invasive direct blood pressure in healthy anesthetized hypotensive and normotensive dogs. Design – Prospective observational study. Setting – University teaching hospital. Animals – Eight crossbred adult dogs. Interventions – Anesthesia was induced with propofol and maintained with isoflurane. A catheter was placed in the dorsal pedal artery to record systolic, mean, and diastolic arterial blood pressures (aSAP, aMAP, and aDAP, respectively). The noninvasive blood pressure device cuff was placed around the contralateral front limb to record noninvasive systolic, mean, and diastolic blood pressure (nSAP, nMAP, and nDAP). Two states of blood pressure (BP) were studied: baseline state was established by keeping end‐tidal isoflurane concentration at 1.2±0.1%. The hypotensive state was achieved by maintaining the same isoflurane concentration while withdrawing approximately 40% of the animal's blood volume until aMAP was stable at approximately 40 mm Hg. At the end of the study, blood was returned to the animal and it was allowed to recover from anesthesia. Measurements and Main Results – Agreement between the direct and indirect BP measurements was determined by the Bland‐Altman method. The SAP and MAP but not DAP bias varied significantly between each BP state. Normotensive absolute biases (mean [SD]) for SAP, MAP, and DAP were ?14.7 mm Hg (15.5 mm Hg), ?16.4 mm Hg (12.1 mm Hg), and ?14.1 mm Hg (15.8 mm Hg), respectively. Absolute biases during the hypotensive state for SAP, MAP, and DAP were ?32 mm Hg (22.6 mm Hg), ?24.2 mm Hg (19.5 mm Hg), and ?16.8 mm Hg (17.2 mm Hg), respectively. Conclusion – The oscillometric device was not reliably predictive of intra‐arterial BP during hypotension associated with acute hemorrhage.     

Effects of a medetomidine-midazolam-butorphanol combination on renal cortical, intestinal and muscle microvascular blood flow in isoflurane anaesthetized dogs: a laser Doppler study

Objective To obtain renal cortical, ileal, colonic and skeletal muscle microvascular blood flow measurements in dogs using the laser Doppler technique and to characterize the effects of medetomidine‐midazolam‐butorphanol combination on these flows. Study Design Prospective randomized experimental study. Animals Fourteen clinically normal beagles (two groups of seven), aged 1–4 years and weighing 13.2 ± 1.8 kg. Methods All dogs were anaesthetized with 1.7% end‐tidal isoflurane in oxygen. In the treatment group, after instrumentation and when anaesthesia was considered stable, medetomidine (1 mg m^?2 body surface area (BSA)) was administered intramuscularly (time 0). Midazolam (1 mg kg^?1) and butorphanol (0.1 mg kg^?1) were administered intravenously 20 minutes later. Atipamezole (2.5 mg m^?2 BSA) was administered intramuscularly 60 minutes after medetomidine. In the control group, saline (0.5, 2.5 and 0.25 mL) was administered at the corresponding times. Heart rate, systolic, diastolic and mean arterial pressures, body temperature, renal cortical, ileal, colonic and skeletal muscle microvascular blood flows were measured before time 0, and 5, 15, 25, 40, 60, 65, 70 and 90 minutes thereafter. Results Heart rate, ileal and skeletal muscle blood flows decreased in the treatment group, while no changes were observed in the control group. Conclusions Laser Doppler flowmetry allowed the measurement of microvascular blood flow in different organs. The medetomidine‐midazolam‐butorphanol combination decreases intestinal and skeletal muscle microvascular blood flows, while renal cortical blood flow is maintained. Clinical relevance Medetomidine‐midazolam‐butorphanol combination can be used to induce a short duration anaesthesia in dogs, but it will induce cardiovascular depression. This depression appears to be accompanied by a redistribution of blood flow.     

5种中草药对肉仔鸡血液生化指标的影响

选用 2 1 6只 1日龄AA鸡 ,随机分为 6组 ,每处理 3个重复 ,每重复 1 2只。试验期为 8周 ,基础日粮为玉米 豆粕型。对照组采食基础日粮 ;试验组日粮分别为基础日粮添加 1 %陈皮、 1 %山楂、 1 %决明子、 1 %绞股蓝和 50mg/kg大蒜素。观察 3期 (0～ 3、 3～ 6、 6～ 8周龄 )的血液生化指标。结果表明 :山楂、决明子和大蒜素对降低血清总胆固醇、甘油三酯、极低密度脂蛋白和低密度脂蛋白 (TC、TG、VLDL和LDL)及升高血液高密度脂蛋白 (HDL)作用显著 (P <0 0 5) ;陈皮和绞股蓝作用不显著 (P >0 0 5)。 5种中草药均有降低血糖和尿素氮及升高血清总蛋白的趋势。     

Effects of induced endometritis on uterine blood flow in cows as evaluated by transrectal Doppler sonography

This study was conducted to evaluate the effects of induced endometritis on uterine blood flow in cows. Transrectal Doppler sonography was performed on uterine arteries of six cyclic cows before and for 4 days after inducing acute endometritis by intrauterine infusion of 720 mg of policresulen, and for 4 days of the following estrous cycle. Time-averaged maximum velocity (TAMV) increased (p < 0.001) and pulsatility index (PI) decreased (p < 0.0001) within 1 h of policresulen administration, and did not change (p > 0.05) in the next 4 days of the same cycle. TAMV and PI values in the subsequent cycle did not differ (p > 0.05) from the values measured before infusion and showed no changes (p > 0.05) within the cycle. Blood flow parameters were not related (p > 0.05) to plasma concentrations of progesterone and estrogen. All cows showed an acute endometritis determined by histopathological findings of biopsy samples taken 1 day after infusion and fibrotic endometrial alterations detected in the subsequent cycle. No relationships were observed between fibrotic changes of the endometrium and uterine blood flow during either cycle. In conclusion, acute inflammation is accompanied by a rise in uterine blood flow, but fibrotic alterations do not seem to be related to Doppler sonographic findings.     

Descending thoracic aortic blood flow parameters during emergent surgery in anesthetized critically ill dogs

Objective: To explore the potential value of transesophageally‐determined descending thoracic aortic blood flow parameters in critically ill dogs undergoing surgery. Design: Observational case series. Setting: Private small animal referral hospital. Animals: Ten anesthetized critically ill dogs that underwent emergent surgery. Interventions: Placement of the ultrasonic transesophageal probe. Measurements and main results: Transesophageally‐determined descending thoracic aortic blood flow, stroke volume, blood velocity, blood acceleration, left ventricular ejection time interval, and heart rate parameters were recorded every minute. Systolic and mean arterial blood pressures were non‐invasively determined and recorded at 1–5 minute intervals. The anesthetist and surgeon were blinded to the descending thoracic aortic blood flow parameters. All dogs received fluid challenges as part of their management, and 2 dogs received dopamine. The variability of the descending thoracic aortic blood flow parameters within each dog was greater than has been reported in non‐critically ill anesthetized dogs. Consistent trends in descending thoracic aortic blood flow parameters after fluid challenges were not found. An escalating dopamine infusion was, however, accompanied by increasing aortic blood flow, stroke volume, acceleration, and peak velocity. Conclusions: Descending thoracic aortic blood flow parameters may eventually be useful for evaluating the responses to and suggesting the need for cardiovascular interventions during emergent surgeries in anesthetized critically ill canine patients. For this to occur, more experience with this technology will be required.