[Show abstract][Hide abstract] ABSTRACT: The aims of this study were (i) to evaluate the relationship between teicoplanin (TEIC) dosage and subsequent trough concentration, (ii) to investigate factors that affect TEIC serum concentration fluctuations and (iii) to examine the association between serum concentration of TEIC and adverse reactions in neonates. A total of 37 eligible neonates (<28 days of age) treated with TEIC from 2008–2012 were included in this study. The median trough concentration in the loading dose regimen of >12–16 mg/kg on Day 1, followed by >6–8 mg/kg every 24 h (q24 h) was 19.6 μg/mL on Day 3 or 4, and the median trough concentration in the maintenance dose regimen of >6–8 mg/kg q24 h was 18.5 μg/mL at steady-state. There were significant correlations between serum creatinine and concentration/dose (C/D) ratio (r = 0.475, P = 0.019), body weight and C/D ratio (r = −0.425, P = 0.038) and corrected gestational age and C/D ratio (r = −0.482, P = 0.017) after administering the loading dose. The incidence of hepatic dysfunction, renal impairment and thrombocytopenia was 14.8%, 20.0% and 14.8%, respectively. There was no significant difference in the incidence of adverse reactions between the trough concentration <20 μg/mL and ≥20 μg/mL groups. These data suggest that the recommended TEIC dosage for neonates is appropriate to achieve and maintain a trough concentration range of 15–30 μg/mL, and it is possible to set the target trough concentration at ≥20 μg/mL for deep-seated infections such as endocarditis, bone and joint infections, and osteomyelitis.
International Journal of Antimicrobial Agents 08/2014; 44(5). DOI:10.1016/j.ijantimicag.2014.07.005 · 4.30 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The purpose of this study was (i) to determine the optimal dosage of teicoplanin for each patient group stratified by renal function and weight based on a population pharmacokinetic model and observed distribution of patient characteristics and (ii) to develop new simplified dosing regimens designed to achieve 15-30μg/mL. Patient data were collected retrospectively from routine therapeutic drug monitoring files of adult patients who were given the standard loading dose regimen of teicoplanin (400mg twice on Day 1, followed by 400mg once daily for 2 days) and whose trough concentration was measured just before administration on Day 4. Monte Carlo simulation was conducted to estimate the trough concentration at 72h after the initial loading dose (C(min)(72h)) and at steady state (C(ss)(min)). The percentage of observed C(min)(72h) in patients who received the standard loading dose regimen outside the non-parametric 90% prediction interval (from 5th to 95th percentile) of the simulated C(min)(72h) was <10%. Simplified loading dose and maintenance dose regimens for each group stratified by renal function and weight were created to achieve C(min)(72h) and C(ss)(min) of 15μg/mL and 20-25μg/mL, respectively. The percentage of C(min)(72h) and C(ss)(min) in the range 15-30μg/mL was 43-65% and 61-82% across each renal function and weight strata, respectively. These new simplified dosing regimens of teicoplanin could be helpful in individual adjustment of the loading and maintenance doses to achieve 15-30μg/mL.
International journal of antimicrobial agents 07/2012; 40(4):344-8. DOI:10.1016/j.ijantimicag.2012.05.025 · 4.30 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Vancomycin chloride (VCM), a glycopeptide antibiotic, is widely used for the therapy of infections caused by methicillin-resistant Staphylococcus aureus. However, nephrotoxicity is a major adverse effect in VCM therapy. In this study, we investigated the cellular mechanisms underlying VCM-induced renal tubular cell injury in cultured LLC-PK1 cells. VCM induced a concentration- and time-dependent cell injury in LLC-PK1 cells. VCM caused increases in the numbers of annexin V-positive/PI-negative cells and TUNEL-positive cells, indicating the involvement of apoptotic cell death in VCM-induced renal cell injury. The VCM-induced apoptosis was accompanied by the activation of caspase-9 and caspase-3/7 and reversed by inhibitors of these caspases. Moreover, VCM caused an increase in intracellular reactive oxygen species production and mitochondrial membrane depolarization, which were reversed by vitamin E. In addition, mitochondrial complex I activity was inhibited by VCM as well as by the complex I inhibitor rotenone, and rotenone mimicked the VCM-induced LLC-PK1 cell injury. These findings suggest that VCM causes apoptotic cell death in LLC-PK1 cells by enhancing mitochondrial superoxide production leading to mitochondrial membrane depolarization followed by the caspase activities. Moreover, mitochondrial complex I may play an important role in superoxide production and renal tubular cell apoptosis induced by VCM.
Free Radical Biology and Medicine 03/2012; 52(9):1865-73. DOI:10.1016/j.freeradbiomed.2012.02.038 · 5.74 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Epirubicin, an anthracycline antitumor drug, often causes vascular injury such as vascular pain, phlebitis, and necrotizing vasculitis. However, an effective prevention for the epirubicin-induced vascular injury has not been established. The purpose of this study is to identify the mechanisms of cell injury induced by epirubicin in porcine aorta endothelial cells (PAECs). PAECs were exposed to epirubicin for 10 min followed by further incubation without epirubicin. The exposure to epirubicin (3-30 μM) decreased the cell viability concentration and time dependently. Epirubicin increased the activity of caspase-3/7, apoptotic cells, and intracellular lipid peroxide levels, and also induced depolarization of mitochondrial membranes. These intracellular events were reversed by glutathione (GSH) and N-acetylcysteine (NAC), while epirubicin rather increased intracellular GSH slightly and L-buthionine-(S,R)-sulfoximine, a specific inhibitor of GSH synthesis, had no effect on the epirubicin-induced cell injury. The epirubicin-induced cell injury and increase of caspase-3/7 activity were also attenuated by p38 mitogen-activated protein kinase (MAPK) inhibitors, SB203580 and PD169316. Moreover, epirubicin significantly enhanced the phosphorylation of p38 MAPK, and these effects were attenuated by GSH and NAC. In contrast, a c-Jun N-terminal kinase inhibitor SP600125, an extracellular signal-regulated kinase inhibitor PD98059, and a p53 inhibitor pifithrin α did not affect the epirubicin-induced cell injury and increase of caspase-3/7 activity. These results indicate that an activation of p38 MAPK by oxidative stress is involved in the epirubicin-induced endothelial cell injury.
Free Radical Biology and Medicine 02/2012; 52(8):1285-93. DOI:10.1016/j.freeradbiomed.2012.02.003 · 5.74 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Oxaliplatin is an important drug used in the treatment of colorectal cancer. However, it frequently causes severe acute and chronic peripheral neuropathies. We recently reported that repeated administration of oxaliplatin induced cold hyperalgesia in the early phase and mechanical allodynia in the late phase in rats, and that oxalate derived from oxaliplatin is involved in the cold hyperalgesia. In the present study, we examined the effects of Ca²⁺ channel blockers on oxaliplatin-induced cold hyperalgesia in rats.
Cold hyperalgesia was assessed by the acetone test. Oxaliplatin (4 mg/kg), sodium oxalate (1.3 mg/kg) or vehicle was injected i.p. on days 1 and 2. Ca²⁺ (diltiazem, nifedipine and ethosuximide) and Na⁺ (mexiletine) channel blockers were administered p.o. simultaneously with oxaliplatin or oxalate on days 1 and 2.
Oxaliplatin (4 mg/kg) induced cold hyperalgesia and increased in the transient receptor potential melastatin 8 (TRPM8) mRNA levels in the dorsal root ganglia (DRG). Furthermore, oxalate (1.3 mg/kg) significantly induced the increase in TRPM8 protein in the DRG. Treatment with oxaliplatin and oxalate (500 μM for each) also increased the TRPM8 mRNA levels and induced Ca²⁺ influx and nuclear factor of activated T-cell (NFAT) nuclear translocation in cultured DRG cells. These changes induced by oxalate were inhibited by nifedipine, diltiazem and mexiletine. Interestingly, co-administration with nifedipine, diltiazem or mexiletine prevented the oxaliplatin-induced cold hyperalgesia and increase in the TRPM8 mRNA levels in the DRG.
These data suggest that the L type Ca²⁺ channels/NFAT/TRPM8 pathway is a downstream mediator for oxaliplatin-induced cold hyperalgesia, and that Ca²⁺ channel blockers have prophylactic potential for acute neuropathy.
[Show abstract][Hide abstract] ABSTRACT: Anticancer drugs are classified as vesicant, irritant, and nonvesicant drugs on the basis of frequency of their vascular disorder. In this study, we compared the injuring effects of three typical anticancer drugs of each class on porcine aorta endothelial cells (PAECs). The concentration inducing 50% cell viability inhibition was lower in the order of vesicant, irritant, and nonvesicant drugs. These results suggest that injuring effects of anticancer drugs on PAECs may be relevant as an indicator of frequency of their vascular disorder, and that this experimental model may be useful for the study of vascular disorder.
[Show abstract][Hide abstract] ABSTRACT: The intravenous injection of vinorelbine often causes venous irritation such as erythema, injection site pain, and phlebitis. The purpose of the present study was to investigate the risk factor associated with the vinorelbine-induced venous irritation and to establish a suitable administration method of vinorelbine.
We analyzed the risk factor associated with venous irritation in 63 patients administered vinorelbine from April 2006 to September 2008. We subsequently changed the regimen of vinorelbine and examined the incidence of venous irritation in 24 patients administered vinorelbine from October 2008 to March 2010.
A multivariate logistic regression analysis revealed that the dose of vinorelbine (≥ 40 mg) was a significant predictor for venous irritation (adjusted odds ratio = 4.39; 95% confidence intervals, 1.33-14.49; p = 0.015). Moreover, the grade of venous irritation in patients administered vinorelbine at the doses of ≥ 40 mg was significantly higher than that in patients administered vinorelbine at the doses of <40 mg (p = 0.011). Based on this result, we altered the volume of normal saline for vinorelbine dissolution from 50 to 100 mL. After the change of regimen, the grade of venous irritation induce by vinorelbine was significantly decreased (p = 0.034), although the incidence was not significantly changed (46.0% versus 33.3%).
The change of regimen of vinorelbine based on the analysis significantly decreased the grade of venous irritation. Pharmacists can contribute to the management for the vinorelbine-induced venous irritation.
Supportive Care in Cancer 07/2011; 20(7):1549-53. DOI:10.1007/s00520-011-1244-3 · 2.36 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Emesis is the most feared side effect in patients who are undergoing cancer chemotherapy. In particular, cisplatin causes severe acute and delayed emesis. Although early vomiting is well controlled by 5-hydroxytryptamine 3 (5-HT(3)) receptor antagonists, delayed-phase vomiting is not sufficiently controlled. Substance P is thought to be involved in the development of emesis, and tachykinin NK(1) receptor antagonists can inhibit delayed vomiting. We previously have reported that substance P is involved in the paclitaxel-induced hypersensitivity reaction in rats, and anti-allergic agent pemirolast reduces these reactions via inhibition of substance P release. In the present study, we investigated the effect of pemirolast on cisplatin-induced kaolin intake, which is an index of nausea/vomiting in the rat. Cisplatin (5 mg/kg, i.p.) induced kaolin intake and reduced normal feed intake from days 1 to 5 after injection. Cisplatin-induced kaolin intake was significantly reduced by co-administration of ondansetron (2 mg/kg, i.p.), a 5-HT(3) receptor antagonist, and dexamethasone (2 mg/kg, i.p.) from days 1 to 5. Similarly, pemirolast (10 mg/kg, p.o.) and the tachykinin NK(1) receptor antagonist aprepitant (10 and 30 mg/kg, p.o.) significantly reduced cisplatin-induced kaolin intake on days 3 and 4. Moreover, pemirolast at the same dose significantly reversed the cisplatin-induced increase in the cerebrospinal fluid level of substance P in rats. These results suggest that substance P is involved in cisplatin-induced kaolin intake in rats, and pemirolast reduces kaolin intake by inhibition of substance P release.
European journal of pharmacology 07/2011; 661(1-3):57-62. DOI:10.1016/j.ejphar.2011.04.026 · 2.53 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Oxaliplatin is a key drug for colorectal cancer, but it causes acute peripheral neuropathy (triggered by cold) and chronic neuropathy (sensory and motor neuropathy) in patients. Neurotropin, a non-protein extract from the inflamed rabbit skin inoculated with vaccinia virus, has been used to treat various chronic pains. In the present study, we investigated the effect of neurotropin on the oxaliplatin-induced neuropathy in rats. Repeated administration of oxaliplatin caused cold hyperalgesia from Day 5 to Day 29 and mechanical allodynia from Day 15 to Day 47. Repeated administration of neurotropin relieved the oxaliplatin-induced mechanical allodynia but not cold hyperalgesia, and inhibited the oxaliplatin-induced axonal degeneration in rat sciatic nerve. Neurotropin also inhibited the oxaliplatin-induced neurite degeneration in cultured pheochromocytoma 12 (PC12) and rat dorsal root ganglion (DRG) cells. On the other hand, neurotropin did not affect the oxaliplatin-induced cell injury in rat DRG cells. These results suggest that repeated administration of neurotropin relieves the oxaliplatin-induced mechanical allodynia by inhibiting the axonal degeneration and it is useful for the treatment of oxaliplatin-induced neuropathy clinically.
European journal of pain (London, England) 04/2011; 15(4):344-50. DOI:10.1016/j.ejpain.2010.08.006 · 2.93 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The painful peripheral neuropathy occurring frequently during chemotherapy with paclitaxel or oxaliplatin is one of their dose-limiting factors. We reported previously that substance P is involved in the pathogenesis of pulmonary hypersensitivity reaction to paclitaxel in rats, and an antiallergic agent pemirolast reverses this reaction via the blockade of release of substance P. In the present study, we investigated the involvement of substance P in paclitaxel-induced peripheral neuropathy compared with that by oxaliplatin. In von Frey and acetone tests in rats repeated administration of paclitaxel (6 mg/kg i.p., once a week for 4 weeks) or oxaliplatin (4 mg/kg i.p., twice a week for 4 weeks) induced both mechanical allodynia and cold hyperalgesia. Paclitaxel-induced peripheral neuropathy was reversed primarily by the acute administration of pemirolast (0.1 and 1 mg/kg p.o.). Moreover, coadministration of the receptor antagonists neurokinin 1 [N-acetyl-l-tryptophan 3,5-bis(trifluoromethyl)benzylester (L-732,138), 100 μg/body i.t.] and neurokinin 2 [5-fluoro-3-[2-[4-methoxy-4-[[(R)-phenylsulphinyl]methyl]-1-piperidinyl]ethyl]-1H-indole (GR159897), 100 μg/body i.t.] strongly reversed paclitaxel-induced neuropathy. On the other hand, oxaliplatin-induced peripheral neuropathy was not reversed by pemirolast. In the in vitro study using cultured adult rat dorsal root ganglion neurons paclitaxel (1000 ng/ml) significantly increased the release of substance P, and pemirolast (100 and 1000 nM) significantly inhibited this increase of substance P release. Oxaliplatin, by contrast, did not increase the release of substance P. These results suggest that substance P is involved in paclitaxel-induced neuropathy, and the mechanism of its action is clearly different from that of oxaliplatin.
Journal of Pharmacology and Experimental Therapeutics 03/2011; 337(1):226-35. DOI:10.1124/jpet.110.175976 · 3.97 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Oxaliplatin is a platinum-based chemotherapy drug characterized by the development of acute and chronic peripheral neuropathies. The chronic neuropathy is a dose-limiting toxicity. We previously reported that repeated administration of oxaliplatin induced cold hyperalgesia in the early phase and mechanical allodynia in the late phase in rats. In the present study, we investigated the involvement of NR2B-containing N-methyl-D-aspartate (NMDA) receptors in oxaliplatin-induced mechanical allodynia in rats.
Repeated administration of oxaliplatin (4 mg/kg, i.p., twice a week) caused mechanical allodynia in the fourth week, which was reversed by intrathecal injection of MK-801 (10 nmol) and memantine (1 μmol), NMDA receptor antagonists. Similarly, selective NR2B antagonists Ro25-6981 (300 nmol, i.t.) and ifenprodil (50 mg/kg, p.o.) significantly attenuated the oxaliplatin-induced pain behavior. In addition, the expression of NR2B protein and mRNA in the rat spinal cord was increased by oxaliplatin on Day 25 (late phase) but not on Day 5 (early phase). Moreover, we examined the involvement of nitric oxide synthase (NOS) as a downstream target of NMDA receptor. L-NAME, a non-selective NOS inhibitor, and 7-nitroindazole, a neuronal NOS (nNOS) inhibitor, significantly suppressed the oxaliplatin-induced pain behavior. The intensity of NADPH diaphorase staining, a histochemical marker for NOS, in the superficial layer of spinal dorsal horn was obviously increased by oxaliplatin, and this increased intensity was reversed by intrathecal injection of Ro25-6981.
These results indicated that spinal NR2B-containing NMDA receptors are involved in the oxaliplatin-induced mechanical allodynia.
[Show abstract][Hide abstract] ABSTRACT: Although S-1 is frequently used in cancer chemotherapy, the drug interaction with warfarin, an anticoagulant agent, is not fully paid attention. In the present study, we investigated retrospectively the timing of expression of blood coagulation abnormality in nine patients treated with warfarin and S-1 concomitantly. In five patients, the dose of warfarin was reduced or interrupted after concomitant use of S-1. The International Normalized Ratio (INR) was significantly increased after combination with S-1 compared with the former value. In all patients, the INR was increased in three weeks after combination with S-1. On the other hand, serum creatinine, aspartate aminotransferase, alanine aminotransferase or serum albumin was not different before and after combination with S-1. These results suggest that the careful monitoring of the blood coagulation ability is necessary in all patients receiving warfarin and S-1 concomitantly.
Yakugaku zasshi journal of the Pharmaceutical Society of Japan 07/2010; 130(7):955-60. DOI:10.1248/yakushi.130.955 · 0.26 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Oxaliplatin is a platinum-based chemotherapy drug characterized by the development of acute and chronic peripheral neuropathies. Mexiletine, an orally available Na(+)-channel blocker, has widely been used in patients with chronic painful diabetic neuropathy. In the present study, we examined the effect of mexiletine on oxaliplatin-induced neuropathic pain in rats. Mexiletine (100, but not 10 and 30, mg/kg, p.o.) completely reversed both mechanical allodynia and cold hyperalgesia induced by oxaliplatin (4 mg/kg, i.p., twice a week). Lidocaine (30, but not 3 and 10, mg/kg, i.p.) also significantly relieved both pain behaviors. These results suggest that mexiletine may be effective in relieving the oxaliplatin-induced neuropathic pain clinically.
[Show abstract][Hide abstract] ABSTRACT: Vinorelbine (VNR), a vinca alkaloid anticancer drug, often causes vascular injury such as venous irritation, vascular pain, phlebitis, and necrotizing vasculitis. The purpose of this study was to identify the mechanisms that mediate the cell injury induced by VNR in porcine aorta endothelial cells (PAECs). PAECs were exposed to VNR for 10 min followed by further incubation in serum-free medium without VNR. The exposure to VNR (0.3-30 microM) decreased the cell viability concentration and time dependently. The incidence of apoptotic cells significantly increased at 12 h after transient exposure to VNR. At the same time, VNR increased the activity of caspases. Interestingly, VNR rapidly depleted intracellular glutathione (GSH) and increased intracellular reactive oxygen species (ROS) production. Moreover, VNR depolarized the mitochondrial membrane potential and decreased cellular ATP levels. These VNR-induced cell abnormalities were almost completely inhibited by GSH and N-acetylcysteine. On the other hand, L-buthionine-(S,R)-sulfoximine, a specific inhibitor of GSH synthesis, aggravated the VNR-induced loss of cell viability. These results clearly demonstrate that VNR induces oxidative stress by depleting intracellular GSH and increasing ROS production in PAECs, and oxidative stress plays an important role in the VNR-induced cell injury.
Free Radical Biology and Medicine 10/2009; 48(1):120-7. DOI:10.1016/j.freeradbiomed.2009.10.032 · 5.74 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Oxaliplatin is a key drug in the treatment of advanced metastatic colorectal cancer, but it causes acute peripheral neuropathy (acral paresthesias triggered by exposure to cold) and chronic neuropathy (abnormal of sensory and motor dysfunction). Oxaliplatin is metabolized to oxalate and dichloro(1,2-diaminocyclohexane)platinum (Pt(dach)Cl(2)). Although the chelating of Ca(2+) with oxalate eliminated from oxaliplatin is thought as one of the reasons for the neuropathy, there is little behavioral evidence. In this study, we investigated the involvement of oxalate in the oxaliplatin-induced peripheral neuropathy in rats. Oxaliplatin (4mg/kg, i.p., twice a week) induced cold hyperalgesia/allodynia (cold-plate and acetone tests) in the early phase, and mechanical allodynia (von Frey test) in the late phase. Oxalate (1.3mg/kg, i.p., twice a week) induced the cold hyperalgesia/allodynia in the early phase, but did not induce the mechanical allodynia. On the other hand, Pt(dach)Cl(2) (3.8mg/kg, i.p., twice a week) induced the mechanical allodynia in the late phase, but did not induce the cold hyperalgesia/allodynia. The pre-administration of calcium or magnesium (0.5mmol/kg, i.v.) before oxaliplatin or oxalate prevented the cold hyperalgesia but not mechanical allodynia. However, the treatment with calcium or magnesium after the development of neuropathy could not attenuate the cold hyperalgesia or mechanical allodynia. These findings suggest the involvement of oxalate in oxaliplatin-induced cold hyperalgesia but not mechanical allodynia, and usefulness of prophylactic treatments with calcium and magnesium on the acute peripheral neuropathy.
[Show abstract][Hide abstract] ABSTRACT: Hepatotoxicity is one of the major complaints that occur during lipid-lowering therapy with 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) reductase inhibitors, known as statins. We reported earlier that lipophilic but not hydrophilic statins induce apoptosis through inhibition of mevalonate biosynthesis cascade in Chang liver cells. The present study was designed to determine the role for small G protein RhoA in the hepatocytotoxicity of statins.
Statin-induced hepatocytotoxicity in HepG2 cells were assessed by WST-8 cell viability assay, JC-1 mitochondrial membrane potential assay and caspase-3/7 activity assay. Cytosolic RhoA was detected by Western blotting and RhoA activation was measured by ELISA.
The lipophilic atorvastatin but not the hydrophilic pravastatin induced the mitochondrial membrane depolarization and the activation of caspase-3/7, which led to cell injury. Supplementation of mevalonate or geranylgeranyl pyrophosphate (GGPP) but not farnesyl pyrophosphate (FPP) reversed these cellular events and cell death induced by atorvastatin. Atorvastatin induced a translocation of RhoA protein into the cytosol and inhibited the activity of the protein. In addition, atorvastatin reduced mitochondrial membrane potential, which was mimicked by GGTase inhibitor GGTI-2147 or the specific RhoA inhibitor such as toxin B and C3 exoenzyme. However, only a few cells revealed mitochondrial membrane depolarization and a loss of viability after exposure to the Rho-kinase inhibitors such as Y-27632 and hydroxy fasudil.
RhoA inactivation and to a lesser extent Rho-kinase inhibition after depletion of GGPP is implicated in the etiology of mitochondrial membrane depolarization and subsequent caspase-dependent cell death induced by the lipophilic statin in HepG2 cells.
[Show abstract][Hide abstract] ABSTRACT: Amphotericin B (AMB) is one of the most effective antifungal agents; however, its use is often limited by the occurrence of adverse events, especially nephrotoxicity. The present study was designed to determine the possible mechanisms underlying the nephrotoxic action of AMB. The exposure of a porcine proximal renal tubular cell line (LLC-PK1 cells) to AMB caused cell injury, as assessed by mitochondrial enzyme activity, the leakage of lactate dehydrogenase, and tissue ATP depletion. Propidium iodide uptake was enhanced, while terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling was not affected by AMB, suggesting a lack of involvement of apoptosis in AMB-induced cell injury. The cell injury was inhibited by the depletion of membrane cholesterol with methyl-beta-cyclodextrin, which lowered the extracellular Na(+) concentration or the chelation of intracellular Ca(2+). The rise in the intracellular Ca(2+) concentration may be mediated through the activation of the ryanodine receptor (RyR) on the endoplasmic reticulum and the mitochondrial Na(+)-Ca(2+) exchanger, since cell injury was attenuated by dantrolene (an RyR antagonist) and CGP37157 (an Na(+)-Ca(2+) exchanger inhibitor). Moreover, AMB-induced cell injury was reversed by PD169316 (a p38 mitogen-activated protein [MAP] kinase inhibitor), c-Jun N-terminal kinase inhibitor II, and PD98059 (a MEK1/2 inhibitor). The phosphorylations of these MAP kinases were enhanced by AMB in a calcium-independent manner, suggesting the involvement of MAP kinases in AMB-induced cell injury. These findings suggest that Na(+) entry through membrane pores formed by the association of AMB with membrane cholesterol leads to the activation of MAP kinases and the elevation of the intracellular Ca(2+) concentration, leading to renal tubular cell injury.
[Show abstract][Hide abstract] ABSTRACT: Paclitaxel is a commonly used anticancer drug, but it frequently causes peripheral neuropathy. Neurotropin, a non-protein extract from inflamed rabbit skin inoculated with vaccinia virus, has been used to treat various chronic painful conditions. In the present study, we investigated the effect of neurotropin on the paclitaxel-induced neuropathy in rats. Repeated administration of paclitaxel induced mechanical allodynia, cold hyperalgesia, and motor dysfunction. These neuropathies were mostly reversed by the repeated administration of neurotropin. Furthermore, neurotropin ameliorated the paclitaxel-induced axonal degeneration in cultured PC12 and rat dorsal root ganglion cells, and in rat sciatic nerve. In addition, neurotropin did not affect the microtubule aggregation or anti-tumour effect induced by paclitaxel in the tumour cell lines or tumour cells-implanted mice. These results suggest that neurotropin reverses the paclitaxel-induced neuropathy without affecting anti-tumour activity of paclitaxel, and therefore may be useful for the paclitaxel-induced neuropathy in clinical settings.
European journal of cancer (Oxford, England: 1990) 12/2008; 45(1):154-63. DOI:10.1016/j.ejca.2008.10.004 · 5.42 Impact Factor