新型c-Myc反义硫代磷酸寡脱氧核苷酸在小鼠体内的药动学

目的 :研究新筛选合成的c Myc基因反义硫代磷酸寡脱氧核苷酸 (antisensephosphorothioateoligodeoxynucleotidestoc Myc ,c MycAS PS ODN )在小鼠体内的药动学、组织分布和排泄情况。方法 :给小鼠按 5 ,10 ,2 0mg·kg- 13个剂量静脉注射3H c MycAS PS ODN后 ,液闪仪测定不同时间点血浆药物浓度 ;按 10mg·kg- 1静脉注射3H c MycAS PS ODN ,测定不同时间组织器官中3H c MycAS PS ODN的含量和其在粪、尿中排泄率 ,药动学统计程序拟合分析。结果 :静脉注射后 3种剂量血浆药物浓度 时间曲线均符合二室分布模型 ,3种剂量下的AUC之间有明显的线性关系 ;多数组织药物分布浓度 2h达高峰 ,肝、脾、肾、肺和骨髓中药物浓度较高 ,2 4h尿、粪总排泄率 82 %。结论 :c MycAS PS ODN在体内分布快 ,除脑、生殖腺等亲脂性组织外 ,其他组织含量高 ;主要通过尿液排泄。     

Pharmacokinetics and tissue distribution of gentiopicroside following oral and intravenous administration in mice.

The pharmacokinetics and tissue distribution of Gentiopicroside (GPS), one of the major active components of the Gentiana species of medicinal plants, was studied following oral and intravenous administration in mice. The distribution of GPS in mice after oral and intravenous doses could be fitted to a two-compartments open model. The serum half-life of GPS was 6.1 h and 2.8 h for intravenous and oral administration, respectively. The Tmax of GPS after oral administration was 0.50 h, and the bioavailability was 39.6%. The AUC gradient in individual tissues following intravenous administration was kidney >serum >liver >spleen >lung >thymus >fat >heart >muscle >stomach >intestinal >brain. The MRT gradient was muscle >serum >lung >spleen >lung >intestinal>heart >stomach >brain >liver >thymus >kidney >fat. Overall the data show that GPS could be absorbed rapidly in mice, but with a low bioavailability, and could distribute to tissues extensively, but was generally cleared quickly with short MRTs. The study demonstrates the need for repeated dosage, or better, a slow release formulation as an ideal means of administering GPS.     

Pharmacokinetics of tryptamide following intravenous administration in rats.

Plasma and tissue levels of N-3-pyridoyl-tryptamine (tryptamide) vs. time were determined in rats following iv administration of various doses: 6.25, 12.5, 25.0 and 37.5 mg/kg. The course of changes was described by the two-compartment open model. The distribution rate constant (alpha, min-1), the elimination rate constant (beta, min-1), the body clearance (Cltot, ml/min) and its fraction absorbed (f,%) values changed depending on the dose and were respectively: 0.107-0.266, 0.0068-0.0126, 5.39-11.59 and 31.77-66.70.     

Acute and subacute toxicity studies on triptolide and triptolide-loaded polymeric micelles following intravenous administration in rodents

Except its anti-tumour effects, triptolide (TP) also shows multiple pharmacological side activities, such as immune-suppressive and male anti-fertility. To increase the therapeutic index of TP, a novel polymeric micelle system containing TP (TP-PM) has been developed to treat tumour. Our previous studies have demonstrated the good anti-tumour efficacy of TP-PM. This paper investigated the acute toxicity in mice and subacute toxicity in rats of TP-PM and TP. Results demonstrated that the LD₅₀ for TP-PM and TP administered intravenously were 1.06 mg/kg and 0.83 mg/kg in mice, respectively. In subacute toxicity study, TP-PM and TP were administered intravenously at the dose levels of 0.1 mg/kg and 0.3 mg/kg for 14 d. Compared to the control, there was significant decrease in the serum AST activities, the testis ACP activities, thymus index, testis index, and significant increase in spleen index, and obvious histopathological changes in rats treated with TP, however, the toxicities of TP-PM on liver, kidney, testis and spleen are slighter than TP. Compared to TP, TP-PM significantly increased the ACP activity of the testis and decreased the MDA level in serum. So, the polymeric micelles may be a novel drug delivery carrier of TP for reducing the toxicities of TP.     

Pharmacokinetics of melamine in pigs following intravenous administration.

Melamine-contaminated pet food was recently added as a supplement to livestock feed. There is little or no information concerning the pharmacokinetics of melamine in livestock, and the aim of this study was to obtain pharmacokinetic parameters for this contaminant in pigs. Melamine was administered intravenously to five weanling pigs at a dose of 6.13 mg/kg and plasma samples were collected over 24 h, extracted for melamine, and then analyzed by HPLC-UV. The data was shown to best fit a one-compartment model with melamine's half-life of 4.04 (+/- 0.37) h, clearance of 0.11 (+/- 0.01) L/h/kg, and volume of distribution of 0.61 (+/- 0.04) L/kg. These data are comparable to the only mammalian study in rats and suggests that melamine is readily cleared by the kidney and there is unlikely to be significant tissue binding. Further tissue residue studies are required to assess the depletion kinetics of this contaminant in the pig which will determine whether residue levels in the kidney should be of public health concern if pigs were exposed to a similar dose.     

Bcl-2硫代反义核酸(G3139)OPC纯化方法

目的 建立Bcl-2硫代反义核酸(G3139)OPC纯化方法。方法 将G3139从合成柱上解离并去保护，用OPC柱分离纯化化学合成的G3139。紫外分光光度计测OD值，20％PAGE鉴定其纯度。结果 经OPC柱纯化后G3139制备量可达mg水平，回收率为66％，电泳结果显示为一条亮带。结论 Bcl-2硫代反义核酸OPC纯化法是一种高效、快速、简便的方法。     

Evidence of enhanced iron excretion during systemic phosphorothioate oligodeoxynucleotide treatment

BACKGROUND: Phosphorothioate oligonucleotides, in general, possess properties that could be utilized in the development of therapeutic heavy metal chelators. METHODS: Iron excretion was measured in 16 patients participating in studies to test the safety of OL(1)p53, a 20-mer phosphorothioate oligonucleotide complementary to p53 mRNA. Patients were given OL(1)p53 at doses of 0.05 to 0.25 mg/kg/h for 10 days by continuous intravenous infusion. Urine was collected during the study and analyzed for iron, copper, cadmium, and zinc. RESULTS: We found that phosphorothioate oligonucleotides have a high affinity for iron as well as several other clinically relevant toxic metals. Analysis of patient urine following administration of OL(1)p53 reveals a 7.5-fold increase in iron excretion at low doses (0.05 mg/kg/h). CONCLUSIONS: Phosphorothioate oligonucleotides may have therapeutic potential as heavy metal chelators. Low doses of phosphorothioate oligonucleotide facilitated the excretion of iron. Renal clearance of iron-phosphorothioate oligonucleotide complexes most likely involves secretion into proximal tubules.     

Absorption and tissue distribution of doxorubicin entrapped in liposomes following intravenous or intraperitoneal administration

Absorption and tissue distribution of free doxorubicin (Dxn) and Dxn entrapped into liposomes have been examined after intravenous (i.v.) or intraperitoneal (i.p.) injection into C57/B1/6 mice. Liposomal encapsulation of Dxn altered its plasma kinetics and tissue distribution. After i.v. administration Dxn in liposomes has a half-life longer than that of free Dxn and it is taken up mostly by tissues rich in reticuloendothelial cells, such as liver and spleen. In the heart and kidney liposomal Dxn reaches a lower concentration than free Dxn. After i.p. injection the tissue distribution of liposomal Dxn is drastically changed. We did not observe the first peak of high concentration in the tissues, the Dxn content in liver and spleen is decreased and its concentration in heart is even more reduced. The results of this study suggest that the route of administration of liposome-entrapped drugs may change both the kinetics of absorption and their tissue distribution and this could result in a different pharmacological effect.     

Pharmacokinetics and tissue distribution of d-alpha-tocopheryl succinate formulations following intravenous administration in the rat

Unlike d-alpha tocopherol (T), d-alpha tocopheryl succinate (TS) has the unique ability to selectively kill tumor cells while protecting normal tissue from toxic oxidative stress. The pharmacokinetics of TS and the serum and tissue disposition of TS were studied in male Sprague-Dawley rats to delineate formulation dependent disposition between TS administered as the Tris salt (TS-T) (a liposomal formulation) or as the free acid (TS-FA) dissolved in polyethylene glycol (PEG) 400. The pharmacokinetics of TS was studied after single intravenous (i.v.) equimolar doses of 124 mg/kg TS-T and 100 mg/kg of TS-FA. Serial blood samples were collected via a catheter inserted into the right jugular vein and serum samples were analysed for TS and T levels using a reverse phase HPLC method. Terminal tissue samples were also collected at 24 and 48 h. After an acute i.v. dose of TS-T, serum AUC, t(1/2), Cl and V(d) of TS were 2601.0 +/- 351.7 microg h/ml, 9.98 +/- 1.02 h, 0.049 +/- 0. 0073 l/h/kg and 0.7 +/- 0.14 l/kg (mean +/- SD), respectively. The acute i.v. administration of TS-FA (PEG formulation) yielded results similar to those observed for TS-T, with a serum AUC, t(1/2), Cl and V(d) of 2553.3 +/- 166.4 microg h/ml, 9.83 +/- 0.86 h, 0.039 +/- 0.0027 l/h/kg and 0.56 +/- 0.09 l/kg (mean +/- SD), respectively. Distribution into tissues and a low Cl was apparent, with the highest concentrations of TS in the liver and lung, regardless of formulation. As expected, baseline endogenous concentrations of T were present in both groups, with a net increase in T levels, occurring as TS was hydrolysed to T, which slowly peaked in serum between 7-8 h post-dose. Intravenous TS administration, regardless of formulation, also resulted in significant T accumulation in all tissues examined, which was especially abundant in the liver and lung. Likewise, there was a lack of significant effect of formulation on the pharmacokinetics and tissue distribution of TS. The only significant formulation difference was a small but significant increase in serum T and liver T levels in the TS in PEG formulation group. These results indicate that TS may be especially useful for the targeted delivery of T and TS to the lung and liver for anti-oxidant and anti-cancer activity.     

Pharmacokinetic characterization of a pig model of ciclosporin A nephrotoxicity following intravenous administration.

BACKGROUND: Recently, we investigated pharmacokinetics and acute nephrotoxicity of oral ciclosporin A (CsA) in pigs. We found that pigs require higher oral CsA doses to obtain comparable area under the concentration versus time curve (AUC) levels to renal transplant patients. The purpose of this study was to examine pharmacokinetics and possible acute renal effects of intravenous CsA in order to further characterize the pig as a model of CsA nephrotoxicity. METHODS: Twenty-eight pigs were randomized into four groups: control and three groups subjected to a single CsA infusion at 3, 6, or 9 mg kg(-1). Blood samples for determination of whole blood CsA concentrations were collected over 7 h under general anaesthesia. At 0, 2, and 5 h, we measured blood pressure, serum creatinine, and haemoglobin, as well as renal blood flow (RBF), relative glomerular filtration rate (rGFR), and kidney volume using magnetic resonance imaging. RESULTS: CsA distribution exhibited two-compartmental behaviour. Compared to renal transplant patients, pigs had approximately the same total clearance of CsA (mean 0.31-0.34lh(-1)kg(-1)), which yields comparable AUC after equivalent dosage in both species. However, the volume of distribution at steady state (mean 1.9-3.0lkg(-1)) was lower in pigs. RBF remained stable in all groups, whereas rGFR decreased in all groups reaching statistical significance in the controls. CONCLUSIONS: Pigs require approximately the same intravenous CsA doses to obtain comparable total AUC to renal transplant patients. Single CsA infusion up to 9 mg kg(-1) for 1h has no deteriorating effect on renal haemodynamics and function.     

The pharmacokinetics of diethanolamine in Sprague-Dawley rats following intravenous administration.

In order to better understand the potential toxicity of diethanolamine (DEA) and preparatory to physiologically-based pharmacokinetic model development, the pharmacokinetics of DEA at high and low internal dose through 96-h post-dosing were determined in female Sprague-Dawley rats administered 10 or 100 mg/kg uniformly labeled 14C-DEA via intravenous injection. Clearance of DEA from blood was calculated to be approximately 84 ml/h/kg at the low dose, increasing to approximately 242 ml/h/kg at the high dose. The primary route of excretion of administered radioactivity, approximately 25-36%, was via the urine as parent compound. A majority of the administered radioactivity was recovered in the tissues of treated rats, especially in the liver and kidneys, suggesting a propensity of DEA or its metabolites for bioaccumulation. An accumulation of radioactivity also occurred gradually in the red blood cells from about 6-96 h post-dosing. Some evidence of dose dependency in the fate of iv-administered DEA was observed, suggesting that saturation of the bioaccumulation process(es) occurred at a dose level of 100 mg/kg.     

Microdialysis evaluation of the brain distribution of stavudine following intranasal and intravenous administration to rats

Intranasal (IN) administration as a potential route of enhancing brain delivery of stavudine (d4T) was investigated in rats using microdialysis as a sampling technique. Sprague-Dawley rats were divided into two groups (n = 7 per group). One group of animals received IN administration of 5 mg/kg d4T (50 microL); the other group was dosed intravenously (IV) at the same dose. Following IN administration, d4T was rapidly and completely absorbed into the systemic circulation with a T(max) of 14 min and an IN bioavailability of 105%. The brain/plasma AUC ratios in the lateral ventricle, caudate putamen, and frontal cortex in the anesthetized and nasal surgery-operated rats were 0.36 +/- 0.090, 0.47 +/- 0.089, and 0.41 +/- 0.087, respectively, whereas they were 0.63 +/- 0.077, 0.62 +/- 0.17, 0.60 +/- 0.13, respectively, following IV dosing to sham animals. The half-life of d4T in the various brain regions was significantly longer than that in plasma (p < 0.05). Moreover, the systemic clearance of d4T was significantly reduced in these anesthetized and nasal surgery-operated animals. Further studies of the effect of anesthesia suggest the additive role of anesthesia, possibly in additional to nasal surgery, in decreasing the systemic clearance. The extent of the brain distribution, however, was not significantly affected by anesthesia. Lack of enhancement of the brain delivery of d4T following IN administration over systemic dosing cannot be attributed to its absorption into systemic circulation, since direct nose-brain transport, if fully functional and effective, should be a parallel and competing process with systemic absorption. The current study results along with several physiological considerations raise a question regarding the overall effectiveness of IN administration for direct delivery of small molecules into brain tissues, particularly where passive diffusion predominates.     

Pharmacokinetics of ceftriaxone following intravenous administration of a 3 g dose

Summary The pharmacokinetic parameters of total (bound and unbound) and free (unbound) ceftriaxone in six healthy volunteers after intravenous injection of 39 were compared with low-dose data from a previous study. The dose-dependent behaviour of total drug was considerably more pronounced after the 3 gram dose. In contrast, total body clearance (Cl _S ^F =258 ml/min), renal clearance (Cl _R ^F =170 ml/min) and volume of distribution (V _D(β) ^F =168 l) of free (unbound) drug did not differ from the data reported earlier. There was no significant change in biological half-life (t_1/2(β)=7.8 h) or in the fraction excreted unchanged in urine (f_u=0.67).     

Midazolam pharmacokinetics following intravenous and buccal administration

Aims Midazolam has good anxiolytic qualities and is a well established premedication agent before anaesthesia or short surgical procedures. The objective of the present study was to determine pharmacokinetic data from individual plasma concentration profiles obtained following intravenous and buccal administration of midazolam.
Methods Eight young healthy volunteers received single doses of 5  mg midazolam i.v. and after a period of 1 week buccally in a cross over manner. Blood samples were obtained up to 480  min. The measurement of plasma midazolam concentrations was by gas-chromatography.
Results The maximum plasma concentration was 55.9  ng  ml⁻¹ (range 35.6–77.9  ng  ml⁻¹ ) at 30  min (range 15–90  min) following buccal administration. AUC was calculated to be 15 016  ng  ml⁻¹ min (s.d. 3778  ng  ml⁻¹ min) following i.v. and 11191  ng  ml⁻¹ min (s.d. 1777  ng  ml⁻¹ min) following buccal midazolam. This gave a mean midazolam bioavailabilty of 74.5%.
Conclusions The pharmacokinetic data presented in this study demonstrate a high bioavailability and reliable plasma concentrations following buccal midazolam. The clinical benefit of buccal midazolam may be in particular patient controlled premedication or sedation in adults.     

Pharmacokinetics of midazolam and alpha-hydroxy-midazolam following rectal and intravenous administration.

1. In an open cross-over trial, plasma concentrations of midazolam were measured in eight healthy male volunteers following administration of 0.3 mg kg-1 body weight given by the rectal and intravenous routes. 2. Maximum plasma concentrations of 92-156 ng ml-1 (mean 118 ng ml-1) were recorded from 20 to 50 min (mean 31 min) after rectal application. The rectal bioavailability was 40-65% (mean 52%) and the terminal half-life was 114-305 min (mean 161 min). 3. A substantial first-pass hepatic effect was observed following rectal administration. 4. No systemic or local intolerance was noted. 5. In conclusion, the rectal route of administration provides a rapid and reliable absorption of midazolam.     

The pharmacokinetics of L-tryptophan following its intravenous and oral administration.

The pharmacokinetics of L-tryptophan (5 g and 7.5 g) have been studied after its intravenous administration to healthy subjects and the results compared with those obtained after oral administration (0.7 g-3.5 g). In order to do this, we have re-analysed previously published data relating to oral administration. The data obtained following the oral administration of L-tryptophan suggest that the total body clearance and apparent volume of distribution are saturable. The pharmacokinetics of tryptophan after intravenous administration of 5 g and 7.5 g were similar to those after the oral administration of 25 and 50 mg kg-1 (i.e. 1.75 g and 3.5 g). Similar pharmacokinetic values were obtained following intravenous tryptophan when the same subjects were retested after a period of 2-4 weeks.     

Pharmacokinetics,bioavailability and tissue distribution of geniposide following intravenous and peroral administration to rats

In order to characterize the pharmacokinetics, bioavailability and tissue distribution of geniposide following intravenous and peroral administration to rats, a reliable gradient HPLC‐based method has been developed and validated. After p.o. administration of geniposide, the peak concentration of geniposide in plasma occurred at 1 h and plasma geniposide was eliminated nearly completely within 12 h. The AUC_{0→ ∞} values of geniposide were 6.99 ± 1.27 h · µg/ml and 6.76 ± 1.23 h · µg/ml after i.v. administration of 10 mg/kg and p.o. administration of 100 mg/kg of geniposide, respectively. The absolute oral bioavailability (%F) of geniposide was calculated as 9.67%. After p.o. administration of geniposide, the AUC_0→4h values in tissues were in the order of kidney > spleen > liver > heart > lung > brain. This study improved the understanding of the pharmacokinetics, bioavailability and tissue distribution of geniposide in rats and may provide a meaningful basis for clinical application of such a bioactive compound of herbal medicines. Copyright © 2013 John Wiley & Sons, Ltd.