高效液相色谱法测定呋塞米片的含量

目的建立高效液相色谱法测定呋塞米片含量的方法。方法采用C18柱(250mm×4.6mm,5μm)色谱柱,以甲醇-水-磷酸盐缓冲液(500∶493∶7)为流动相,流速1.0m l.m i-n 1,检测波长为286nm。结果呋塞米在0.597~3.980μg范围内进样量与峰面积呈良好的线性关系(r=0.9998);平均回收率为99.31%,RSD为1.01%,n=9。结论本方法结果准确,重现性较好。     

High and concentration-proportional accumulation of [3H]-nitrendipine by intact cardiac tissue.

The binding of [3H]-nitrendipine to intact, electrically driven isolated left atria of guinea-pigs was investigated over the concentration range 10(-10) M to 3 X 10(-5) M. A high affinity binding site saturable in the nM range as found in ventricular homogenates could not be detected. Instead the accumulation of nitrendipine in intact atria was found to be proportional to the concentration from 10(-10) M to 10(-6) M; beyond 10(-6) M the binding started to become saturated. Nitrendipine was highly accumulated in atrial tissue. The cell:medium ratios amounted to about 120 in the range from 10(-10) M to 10(-6) M. The concentration-response curve for the negative inotropic action of nitrendipine yielded an ED50 of 3 X 10(-7) M, thus lying within the range of concentration-proportional accumulation. The reduction of the contractile force proceeded faster (t1/2 less than 10 min) than the uptake process t1/2 approximately 40 min) suggesting that it is the binding of nitrendipine into a superficial compartment, which interferes with the excitation-contraction coupling. The results suggest that the high concentration of nitrendipine present in hydrophobic cellular compartments such as the plasmalemma might be involved in its pharmacological action.     

高效液相色谱法测定呋噻米注射液的含量

目的建立高效液相色谱法测定定呋噻米注射液含量的方法。方法C18(150mm×4.6mm,5μm)色谱柱,以水-甲醇-磷酸盐缓冲液(50∶49∶1)为流动相,流速1.0ml.min-1,检测波长为275nm。结果呋噻米在0.049~0.292μg范围内进样量与峰面积呈良好的线性关系(r=0.9999);平均回收率为98.94%,RSD为1.24%,n=9。结论本方法结果准确,重现性较好。     

速尿联合多巴胺治疗急性肾炎伴急性肾功能衰竭的临床研究

目的 探讨急性肾炎(AGN)伴急性肾功能衰竭(ARF)患者应用速尿联合多巴胺治疗的临床效果.方法 选取本院2013年6月至2016年3月收治的98例AGN伴ARF患者,随机均分为两组.对照组给予常规综合治疗;观察组在对照组基础上给予速尿联合多巴胺治疗.比较两组临床疗效,尿蛋白(PRO)、血尿素氮(BUN)恢复正常时间及住院时间,治疗前后24h尿蛋白定量、BUN及血肌酐(SCr)水平等肾功能指标.结果 观察组总有效率为93.88％,明显高于对照组的77.55％(P＜0.05);观察组PRO、BUN恢复正常时间和住院时间均显著短于对照组(P＜0.01);两组治疗后24h尿蛋白定量、BUN及SCr水平与治疗前比较,均显著降低(P＜0.01),但观察组的改善程度更为显著(P＜0.01).结论 AGN伴ARF应用速尿联合多巴胺治疗效果突出,能有效遏制ARF病情发展,快速恢复肾功能,具有一定临床参考价值.     

In vitro accumulation of tetrodotoxin in pufferfish liver tissue slices.

The liver tissue slices of pufferfish accumulate in vitro tetrodotoxin (TTX), when incubated with minimum essential medium containing TTX. In the case of Takifugu rubripes liver slices incubated at a concentration of 25 microg TTT/ml, TTX of 3.9 microg/g was first detected at 2h and increased to 15 microg/g at 48h. The TTX content accumulated was not decreased, even when the slices were further incubated without TTX for additional 48h. Another species of pufferfish T. paradalis also showed similar trend in TTX accumulation, except they accumulated higher concentration of TTX (36.4 microg/g at 48h) than T. rubripes. On the contrary, in the cases of the liver slices from parrot-bass Oplegnathus fasciatus, green ling Hexagrammos otakii and filefish Thamnaconus modestus incubated at a concentration of 25 microgTTX/ml, TTX of 3-4 microg/g was detected even at 0.5h. However, no significant change in TTX contents was recognized during the incubation for 48h. Further incubation of the filefish liver slices without TTX for additional 48h did not decrease the TTX content. It is unlikely that the liver slices of filefish as well as pufferfish rapidly excrete TTX. These results suggest that the difference in the accumulation of TTX between pufferfish and filefish livers is ascribable to the difference not in the TTX excreting ability but in the ability to take up TTX.     

Pathophysiology of renal tissue damage by iodinated contrast media

1. The present review focuses on the cytotoxic effects of iodinated contrast media (CM) that are shared by all types of CM. 2. Although the clinical nephrotoxicity of CM has been progressively improved, all currently available CM still possess a level of cytotoxicity, which is probably caused by iodine. 3. The toxicity caused by specific CM properties, such as osmolarity, viscosity and ionic strength, can be differentiated from the cytotoxicity common to all CM in studies using cell culture, isolated blood vessels and isolated tubules. 4. The cytotoxicity induced by CM leads to apoptosis and cell death of endothelial and tubular cells and may be initiated by cell membrane damage, together with oxidative stress. 5. Cell damage may be aggravated by factors such as tissue hypoperfusion and hypoxia, properties of individual CM, such as ionic strength, high osmolarity and/or viscosity, and clinically unfavourable conditions. 6. Clinically detectable renal failure may result from the summation of all these factors.     

Improved method for quantification of tissue PMN accumulation measured by myeloperoxidase activity

Myeloperoxidase (MPO) was used as a marker enzyme for measuring polymorphonuclear leukocyte (PMN) accumulation in tissue samples. The MPO recovery from kidney, liver, myocardium, skeletal muscle (iliopsoas), and skin was measured, and a variation of 5%–100% was found, depending on the tissue analyzed. The recovery could be improved to 100% in all tissues by incubation of the tissue samples at 60°C for 2 hr. This improved method was used to measure PMN accumulation in rabbit myocardium after regional ischemia and reperfusion. The MPO activity increased fivefold in the occluded area as compared with intact myocardium. Treatment with IB4, a monoclonal antibody recognizing the leukocyte adhesion molecule Mac-1, decreased the MPO activity in the occluded area almost to the level in intact myocardium.     

Oral exposure of Kunming mice to diisononyl phthalate induces hepatic and renal tissue injury through the accumulation of ROS. Protective effect of melatonin

Diisononyl phthalate (DINP) has been widely used in polyvinyl chloride (PVC) products and is ubiquitous as a substitute; however, its toxicity due to exposure remains to be determined. This study investigated the oxidative damage induced by DINP and the induced production of the pro-inflammation cytokines interleukin-1 (IL-1) and tumour necrosis factor-α (TNF-α). Oral exposure to DINP induced oxidative damage and inflammatory responses in liver and kidney tissues through the accumulation of ROS, which may be an underlying mechanism for its toxicity. These changes may contribute to hepatic and renal histopathological alterations. Our data suggest that oxidative stress is involved in DINP-induced toxicity and that the co-administration of melatonin exerts a protective effect against DINP-induced toxicity.     

Effects of polymyxin antibiotics on iodohippurate accumulation in rabbit renal cortical slices.

The in vitro effects of polymyxin antibiotics on 0-125I-hippurate (OIH) accumulation in rabbit renal cortical slices were studied using incubation media with pH ranging from 6.9 to 7.9 and containing polymyxin B sulfate, colistin sulfate, sodium colistimethate and antibacterially inactive N-succinyl colistin in concentrations ranging from 1 to 2,000 microgram base/ml. Polymyxin B, colistin and colistimethate depressed OIH accumulation significantly in concentrations greater than or equal to 300 microgram/ml. The effects on accumulation were clearly pH-dependent and most pronounced at alkaline pH. N-Succinyl colistin had only a marginal influence on accumulation, even in high concentrations. Colistimethate produced a significantly smaller decrease in accumulation at all pH values than both polymyxin B and colistin. The results suggest that the presence of free amino groups is necessary to obtain a decrease in accumulation and correlate with the known in vivo nephrotoxicity of these antibiotics.     

Mast cell accumulation precedes tissue fibrosis induced by intravenously administered amorphous silica nanoparticles

Despite the increasing use of amorphous silica nanoparticles (SNPs) in biomedical applications, their toxicity after intravenous administration remains a major concern. We investigated the effects of single 7?mg/kg intravenous infusions of 13?nm SNPs on hemodynamic parameters in rats. Hematological and biochemical parameters were assessed at 7, 30, and 60 d post treatment. Silicon content in the liver, lungs, heart, and kidney was analyzed, as well as tissue histology with special emphasis on mast cell (MC) content. SNP infusion had no effect on hemodynamics, nor did it alter hematological or biochemical parameters. SNP retention in the liver was conspicuous for up to 60 d. Among the other organs analyzed, silicon content was significantly increased only in the lung at 1-h post infusion. Despite the relatively low dose, SNP administration caused extensive liver remodeling, including the formation of multiple foreign body-type granulomas starting 7 d post treatment, and subsequent development of fibrosis. Histopathological changes in the liver were not preceded by hepatocyte necrosis. We found increased MC abundance in the liver, lungs, and heart starting on day 30 post treatment. MC recruitment in the liver preceded fibrosis, suggesting that MCs are involved in liver tissue remodeling elicited by intravenously administered SNPs.     

Steady state verapamil tissue distribution in the dog: differing tissue accumulation

Plasma, heart, and extracardiac tissue verapamil concentrations were measured after sustained intravenous infusions in 11 dogs to determine the differential tissue accumulation of verapamil. A steady state verapamil concentration of 327 +/- 50 ng/ml decreased the mean arterial blood pressure from 104 +/- 9 to 90 +/- 6 mm Hg (p = 0.08) and the P-R interval increased from 118 +/- 4 to 176 +/- 13 ms (p less than 0.001) with second-degree atrioventricular block developing in 6 animals. Verapamil accumulated in organs in the following order: Lung much greater than kidney greater than spleen greater than ventricular myocardium = liver greater than atrial myocardium greater than cerebral cortex greater than fat = skeletal muscle. Levels in the ventricular free wall were consistently greater than atrial levels, but no difference was observed between left versus right-sided cardiac chambers. In summary, affinity of different organs for verapamil is highly variable and organ-specific; furthermore, differential intracardiac chamber accumulation occurs.     

Gentamicin disposition and tissue accumulation on multiple dosing

Gentamicin pharmacokinetics was examined in a group of 47 patients with stable renal function treated an average of 10 days for severe infection. Serum concentrations rose continually during treatment, and declined in two phases after the drug was stopped, with a mean half-life of 112hr (range 27–693 hr) in the second phase. A two-compartment model was used to describe the biphasic decline in serum concentrations and to calculate the amount of drug in the tissue compartment at all times during and after treatment. Predicted tissue amounts of gentamicin rose continually on multiple dosing in all patients. In six patients who died, postmortem tissues were obtained to quantitate recovery. In all cases, the predicted amount of gentamicin in tissues was in close agreement with the amount recovered at autopsy. Tissue distribution and accumulation constitute a major reason for variability in gentamicin pharmacokinetics and explain both the rising peak and trough serum concentrations and the prolonged detection of gentamicin in serum and urine after the drug is stopped.Supported in part by Grant GM 20852 from the National Institutes of General Medical Sciences, NIH.     

前列地尔联合甘露醇及呋塞米序贯治疗急性肾功能衰竭

目的观察前列地尔(PGE1)联合甘露醇及呋塞米序贯治疗急性肾功能衰竭(ARF)1期的疗效。方法选择发病6～12h的ARF1期60例,随机分为治疗组32例和对照组28例。治疗组用PGE1联合甘露醇、呋塞米治疗,对照组用小剂量多巴胺联合呋塞米治疗。两组原发病及对症支持治疗相同。观察两组治疗后尿量、血肌酐(SCr)、血尿素氮(BUN)变化。结果治疗组的显效率及治愈率均优于对照组(﹡χ2=5.17,﹡P<0.05;χ2=5.16,P<0.05)。结论 PGE1联合甘露醇及呋塞米序贯治疗ARF1期疗效较佳,适合目前临床使用。     

Furosemide dynamics: influence of dietary sodium and of saralasin.

The influence of dietary sodium and saralasin on the natriuretic and diuretic response to furosemide (5 mg/kg i.v.) was studied in three groups of conscious rabbits maintained for 4 weeks on either a normal sodium diet (NSD), or a low sodium diet (LSD) or a high sodium diet (HSD). Neither the sodium content in the diet nor saralasin affected glomerular filtration rate or renal plasma flow. Compared to the NSD, an LSD did not affect the furosemide-induced increment in urinary excretion of sodium (dUNaV) but increased the increment in urinary excretion (dUV) (p less than 0.05). An HSD reduced the furosemide-induced dUNaV and dUV (p less than 0.05). Plasma renin activity (PRA) increased following furosemide administration in animals on an NSD and an LSD, but not in those on an HSD. Independent of diet, a positive correlation occurred between the increment in PRA and the dUNaV (p less than 0.001). Saralasin increased PRA and decreased baseline urinary excretion of sodium (UNaV). In addition, in rabbits on an LSD, saralasin reduced the furosemide-induced dUNaV and dUV by 34 and 27% (p less than 0.05), respectively. It is concluded that furosemide-induced diuresis is increased in rabbits on an LSD and decreased in rabbits on an HSD. In animals on an LSD, the increase in furosemide response appears to be associated with changes in the activity of the renin-angiotensin system and in rabbits on an HSD, the decrease in furosemide effect is probably the net result of several factors.     

Increased accumulation of the lipophilic cation tetraphenylphosphonium+ by cyclopiazonic acid-treated renal epithelial cells

Pig kidney renal epithelial cells (LLC-PK1) in culture were used to determine the effects of cyclopiazonic acid (CPA) on the uptake of the transmembrane potential probe, [3H]tetraphenylphosphonium bromide (TPP+). CPA had a significant stimulatory effect on TPP+ accumulation, which occurred in a dose-related manner. TPP+ accumulation in the presence of CPA was significantly reduced by high-potassium media (HK) and carbonylcyanide m-chlorophenylhydrazone (CCCP), but neither HK nor the protonophore CCCP, could completely abolish the stimulatory effect of CPA. The apparent transmembrane potential difference (delta psi), calculated based on the difference in accumulation of TPP+ in low-potassium and HK media, ranged from -55.9 to -85.7 mV for control cells and -89.4 to -109.0 mV for CPA-treated cells (20 mg CPA/I). The mechanism of CPA stimulation of TPP+ accumulation was not known. However, it was hypothesized that the effect could be a result of alterations in ion pumps or altered membrane permeability. The fact that the stimulatory effect could not be completely abolished by high potassium or CCCP suggested that there was some interaction between CPA and TPP+ or there were sites of TPP+ accumulation that were insensitive to K+ and H+ permeability.     

HPLC法测定注射用呋塞米中有关物质的含量

目的:建立以高效液相色谱法测定注射用呋塞米中有关物质含量的方法。方法:色谱柱为Hypersil -ODS,流动相为水-四氢呋喃-冰醋酸(70∶30∶1) ,流速为1.0mL·min-1,检测波长为254nm,进样量为20μL,以自身对照法计算有关物质的含量。结果:呋塞米检测浓度的线性范围为50～2 000μg·mL-1(r=0.999 7) ,有关物质平均含量为0.78%。结论:本方法简便、快速、准确、重现性好,可用于该制剂的质量控制。     

紫外-可见分光光度法测定呋塞米片含量的不确定度评定

目的建立紫外-可见分光光度法测定呋塞米片含量不确定度的评定方法。方法建立数学模型,分析实验过程中不确定度的影响因素并对其进行评估,由此得出合成不确定度和扩展不确定度。结果扩展不确定度为1.0%（k=2）,含量测定结果可表示为（98.5±1.0）%。结论建立的不确定度计算方法可适用于紫外-可见分光光度法测定各种制剂含量的不确定度。