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Shin C, Lee J, Kim YK, Nam H, Yoon EJ, Shin SA, Kim H, Jeon B. Cognitive decline in association with hyposmia in idiopathic rapid eye movement sleep behavior disorder: a prospective 2‐year follow‐up study. Eur J Neurol 2019; 26:1417-1420. [DOI: 10.1111/ene.14025] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2019] [Accepted: 06/18/2019] [Indexed: 11/29/2022]
Affiliation(s)
- C. Shin
- Department of Neurology Kyung Hee University Hospital SeoulKorea
| | - J.‐Y. Lee
- Department of Neurology Seoul National University Boramae Hospital SeoulKorea
| | - Y. K. Kim
- Department of Nuclear Medicine Seoul National University Boramae Hospital SeoulKorea
| | - H. Nam
- Department of Neurology Seoul National University Boramae Hospital SeoulKorea
| | - E. J. Yoon
- Department of Nuclear Medicine Seoul National University Boramae Hospital SeoulKorea
| | - S. A. Shin
- Department of Nuclear Medicine Seoul National University Boramae Hospital SeoulKorea
| | - H.‐J. Kim
- Department of Neurology Seoul National University Hospital Seoul Korea
| | - B. Jeon
- Department of Neurology Seoul National University Hospital Seoul Korea
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Yoon EJ, Kim YK, Lee HS, Shin HI, KIM SE. Evaluation of tDCS effect on regional cerebral glucose metabolism in patients with central pain. Neuroimage 2009. [DOI: 10.1016/s1053-8119(09)70628-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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Abstract
Phospholipase D-mediated hydrolysis of phosphatidylcholine is stimulated by protein kinase C and the monomeric G proteins Arf, RhoA, Cdc42, and Rac1, resulting in complex regulation of this enzyme. Using purified proteins, we have identified a novel inhibitor of phospholipase D activity, Gbetagamma subunits of heterotrimeric G proteins. G protein-coupled receptor activation alters affinity between Galpha and Gbetagamma subunits, allowing subsequent interaction with distinct effectors. Gbeta1gamma1 inhibited phospholipase D1 and phospholipase D2 activity, and both Gbeta1gamma1 and Gbeta1gamma2 inhibited stimulated phospholipase D1 activity in a dosedependent manner in reconstitution assays. Reconstitution assays suggest this interaction occurs through the amino terminus of phospholipase D, because Gbeta1gamma1 is unable to inhibit an amino-terminally truncated phospholipase D construct, PLD1.d311, which like full-length phospholipase D isoforms, requires phosphatidylinositol-4,5-bisphosphate for activity. Furthermore, a truncated protein consisting of the amino-terminal region of phospholipase D containing the phox/pleckstrin homology domains was found to interact with Gbeta1gamma1, unlike the PLD1.d311 recombinant protein, which lacks this domain. In vivo, expressed recombinant Gbeta1gamma2 was also found to inhibit phospholipase D activity under basal and stimulated conditions in MDA-MB-231 cells, which natively express both phospholipase D1 and phospholipase D2. These data demonstrate that Gbetagamma directly regulates phospholipase D activity in vitro and suggest a novel mechanism to negatively regulate phospholipase D signaling in vivo.
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Affiliation(s)
- A M Preininger
- Department of Pharmacology: 442 RRB, Vanderbilt University School of Medicine, 23rd Ave. South and Pierce, Nashville, TN 37232-6600, USA
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Kim BS, Ahn YM, Kim J, Yoon EJ, Choi SH. Clinical utility of adenosine triphosphate-based chemosensitivity response assay (ATP-CRA) in non-small cell lung cancer: Preliminary study. J Clin Oncol 2004. [DOI: 10.1200/jco.2004.22.90140.7259] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Affiliation(s)
- B.-S. Kim
- Seoul Veterans Hospital, Seoul, Republic of Korea; Petagen Inc, Seoul, Republic of Korea
| | - Y. M. Ahn
- Seoul Veterans Hospital, Seoul, Republic of Korea; Petagen Inc, Seoul, Republic of Korea
| | - J. Kim
- Seoul Veterans Hospital, Seoul, Republic of Korea; Petagen Inc, Seoul, Republic of Korea
| | - E. J. Yoon
- Seoul Veterans Hospital, Seoul, Republic of Korea; Petagen Inc, Seoul, Republic of Korea
| | - S. H. Choi
- Seoul Veterans Hospital, Seoul, Republic of Korea; Petagen Inc, Seoul, Republic of Korea
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Park HC, Hong SK, Kim HS, Kim SH, Yoon EJ, Kim CH, Miki N, Huh TL. Structural comparison of zebrafish Elav/Hu and their differential expressions during neurogenesis. Neurosci Lett 2000; 279:81-4. [PMID: 10674626 DOI: 10.1016/s0304-3940(99)00940-4] [Citation(s) in RCA: 70] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The present communication reports the isolation and characterization of three new zebrafish elav/Hu (Kim, C.-H., Ueshima, E., Muraoka, O., Tanaka, H., Yeo, S.-Y., Huh, T.-L. and Miki, N., Zebrafish elav/HuC homologue as a very early neuronal marker. Neurosci. Lett., 216 (1996) 109-112) homologues, HuA, HuD and HuG. While HuA and HuG showed weak and ubiquitous expressions, HuD, as well as HuC, were specifically expressed in the neuronal cells. The first expression of HuD was detectable of the 10-somite stage, that is, several hours later than HuC. After 24 h of embryonic development, although HuD and HuC expressions overlapped overall, the cells expressing HuD were restricted to subsets of the HuC-positive neuronal cells in the brain and spinal cord. These differentially regulated spatial and temporal expression patterns implied distinct roles for HuC and HuD in neuronal determination and neuronal differentiation, respectively.
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Affiliation(s)
- H C Park
- Department of Genetic Engineering, College of Natural Sciences, Kyungpook National University, Taegu, South Korea
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Alessi CA, Yoon EJ, Schnelle JF, Al-Samarrai NR, Cruise PA. A randomized trial of a combined physical activity and environmental intervention in nursing home residents: do sleep and agitation improve? J Am Geriatr Soc 1999; 47:784-91. [PMID: 10404920 DOI: 10.1111/j.1532-5415.1999.tb03833.x] [Citation(s) in RCA: 156] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
OBJECTIVES The purpose of this study was to test whether an intervention combining increased daytime physical activity with improvement in the nighttime environment improves sleep and decreases agitation in nursing home residents. DESIGN A randomized trial. SETTING One community nursing home in the Los Angeles, California area. PARTICIPANTS Twenty-nine incontinent residents (mean age 88.3 years, 90% female). INTERVENTION Subjects were randomized to receive either (1) an intervention combining increased daytime physical activity (14 weeks in duration) plus a nighttime program (5 nights in duration) to decrease noise and sleep-disruptive nursing care practices (intervention group), or (2) the nighttime program alone (control group). MEASUREMENTS Daytime physical activity monitors and structured physical function assessments; nighttime wrist activity monitors to estimate nighttime sleep; and timed daytime behavioral observations of sleep versus wakefulness, either in or out of bed, and agitation. RESULTS Physical function measures did not change significantly (MANOVA for repeated measures, group by time effect). Wrist actigraphy estimation of nighttime percent sleep (time asleep over time monitored in bed at night) increased in intervention subjects from 51.7% at baseline to 62.5% at follow-up compared with 67.0% at baseline to 66.3% at follow-up in controls (MANOVA, group by time, F = 4.42, P = .045, df = 27). At follow-up, intervention subjects averaged a 32% decrease in the percent of daytime observations in bed compared with baseline, with essentially no change in controls (MANOVA, group by time, F = 5.31, P = .029, df = 27). Seven of 15 intervention subjects had a decrease in observed agitation at follow-up, compared with baseline, versus only 1 of 14 controls with a decrease in observed agitation. CONCLUSIONS This study provides preliminary evidence that an intervention combining increased physical activity with improvement in the nighttime nursing home environment improves sleep and decreases agitation in nursing home residents.
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Affiliation(s)
- C A Alessi
- University of California, Los Angeles, Multicampus Program in Geriatric Medicine and Gerontology, USA
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Yoon EJ, Shim HJ, Lee JJ, Lee SD, Kim WB, Yang J, Lee MG. Pharmacokinetics of DA-125, a new anthracycline, after intravenous administration to spontaneously hypertensive rats and DOCA-salt-induced hypertensive rats. Drug Metab Dispos 1997; 25:66-74. [PMID: 9010632] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Pharmacokinetic parameters-including tissue distribution, biliary excretion, and urinary excretion of M1-M4-were compared after an intravenous administration of DA-125 (a new anthracycline derivative; 20 mg/kg body weight) to male spontaneously hypersensitive rats (SHRs) at 16 weeks (an animal model for human primary hypertension) and at 6 weeks (corresponding to the early phase of the development of hypertension, at which time blood pressure remains within the normotensive range) of age and their age-matched control Kyoto-Wistar rats, and male deoxycorticosterone acetate-salt-induced Sprague-Dawley rats (DOCA-salt rats, an animal model for human secondary hypertension) at 16 weeks of age and their age-matched control Sprague-Dawley rats. Mean plasma concentrations of both M2 and M4, and the resultant area under the plasma concentration-time curve from time 0 to last measured time [AUCT; M2 (68.9 vs. 29.3 micrograms-min/ml) and M4 (53.4 vs. 33.4 micrograms-min/ml)], increased significantly in SHRs at 16 weeks of age, compared with their control rats. Similar results were also obtained from DOCA-salt rats at 16 weeks of age, compared with their control rats. However, values were not significantly different between SHRs at 6 weeks of age and their control rats. Previous data indicated that the significant increase in plasma concentrations and the resultant AUCT values of both M2 and M4 in SHRs at 16 weeks of age were due to the hypertension state itself, and not to any hereditary characteristics of the SHRs. The significantly increased plasma concentrations and the resultant AUCT values of M2 in both SHRs and DOCA-salt rats at 16 weeks of age were due to the significantly decreased biliary excretion of M2 and possibly to the increased amount of aldo-keto reductase in the liver. However, the increase in the two aforementioned pharmacokinetic parameters in the case of M4 were possibly due solely to the increased amount of aldo-keto reductase in the liver.
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Affiliation(s)
- E J Yoon
- College of Pharmacy, Seoul National University, South Korea
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Yoon EJ, Lee WI, Shim HJ, Lee SD, Kim WB, Yang J, Lee MG. Comparison of pharmacokinetics of M1, M2, M3, and M4 after intravenous administration of DA-125 or ME2303 to mice and rats. New adriamycin analogues containing fluorine. Biopharm Drug Dispos 1996; 17:373-420. [PMID: 8830976 DOI: 10.1002/(sici)1099-081x(199607)17:5<373::aid-bdd373>3.0.co;2-u] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The pharmacokinetics of M1, M2, M3 and/or M4 were compared after intravenous (i.v.) administration of DA-125 and/or ME2303 to mice (25 mg kg(-1)) and rats (5, 10, 20, 30, and 40 mg kg(-1)). The mean plasma concentrations of M1 were detected up to 8 h after i.v. administration of both DA-125 and ME2303 to mice, and were significantly higher for DA-125 than ME2303; this resulted in a considerably greater AUC (303 against 148 micrograms min mL(-1)) and a considerably slower CL of M1 (69.3 against 136 mL min-1 kg(-1)) after i.v. administration of DA-125. The MRT (371 against 189 min) and CLNR of M1 (68.7 against 136 mL min-1 kg(-1)) were considerably greater and slower, respectively, after i.v. administration of DA-125. The mean plasma concentrations of M2 were detected up to 8 and 4 h after i.v. administration of DA-125 and ME2303, respectively, to mice and were significantly higher for DA-125 than ME2303, resulting in a considerably greater AUC of M2 (148 against 27.1 micrograms min mL(-1)) after i.v. administration of DA-125. The mean plasma concentrations of M3, being the lowest among M1-M4, were detected only up to 15 min after i.v. administration of both DA-125 and ME2303 to mice, and were comparable after i.v. administration of DA-125 and ME2303 to mice. The mean plasma concentrations of M4 were detected up to 8 h after i.v. administration of both DA-125 and ME2303 to mice, and were higher after i.v. administration of DA-125 than ME2303, resulting in a considerably greater AUC of M4 (197 against 61.9 micrograms min mL(-1)) after i.v. administration of DA-125. Similar results on M1 and M2 were also obtained from rats: the mean plasma concentrations of both M1 and M2 were significantly higher after i.v. administration of DA-125, 10 mg kg(-1), than after ME2303. The plasma concentrations of M1, M2, and M4, and hence their AUCs, were significantly higher after i.v. administration of DA-125, 5, 10, 20, 30, and 40 mg kg(-1), to rats than after ME2303: the mean plasma concentrations of M2, approximately 0.1-0.4 micrograms mL(-1), were maintained from 30 min to 8-10 h after i.v. administration of DA-125, 20, 30, and 40 mg kg(-1), to rats; the plasma concentrations of M3 were the lowest among M1-M4 at all DA-125 doses; and those of M1 and M4 were maintained for a long period of time. However, after i.v. administration of M2, 5 mg kg(-1), to rats, the mean plasma concentrations of M2 were detected up to 60 min with a mean terminal half-life of only 38.8 min, and the concentrations of M3 were negligible. After i.v. administration of M3, 5 mg kg(-1), to rats, the mean plasma concentrations of M3 were detected up to 15 min; the plasma concentrations of M4, reaching their peak at 5 min, decayed more slowly and were higher than those of M3. The AUC of M4 after i.v. administration of M3, 5 mg kg(-1), was comparable to that after i.v. administration of M4, 5 mg kg(-1), to rats, suggesting that M4 is formed fast and almost completely from M3. M1 was not detected in plasma after i.v. administration of either M2 or M3 to rats. After i.v. administration of M4, 5 mg kg(-1), to rats, the mean plasma concentrations of M4 decayed fast with a mean terminal half-life of 43.9 min and neither M2 nor M3 were detected in plasma. The following disposition mechanisms for M1, M2, M3, and M4 after i.v. administration of DA-125 to rats could be obtained from the above data; (i) the maintenance of plasma concentrations of M2 for a longer period of time after i.v. administration of DA-125 than those after i.v. administration of M2 could be due to the continuous formation of M2 from M1; (ii) the lowest plasma concentrations of M3 among M1-M4 after i.v. administration of DA-125 could be due to the fast and almost complete information of M4 from M3 as soon as M3 is formed from M1, and not due to the fast renal excretion of unchanged M3; (iii) M4 was exclusively and continuously formed from M3 and the formation of M4 from M2 was negligible; and (i.v.) reversible me
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Affiliation(s)
- E J Yoon
- College of Pharmacy, Seoul National University, Korea
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Kim YG, Yoon EJ, Yoon WH, Shim HJ, Lee SD, Kim WB, Yang J, Lee MG. Pharmacokinetics of DA-125, a new anthracycline, after intravenous administration to uranyl nitrate-induced acute renal failure rats or protein-calorie malnutrition rats. Biopharm Drug Dispos 1996; 17:183-95. [PMID: 8983394 DOI: 10.1002/(sici)1099-081x(199604)17:3<183::aid-bdd955>3.0.co;2-m] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The pharmacokinetics of DA-125 were compared after intravenous (i.v.) administration of the drug, 10 mg kg-1, to control male Sprague-Dawley rats (n = 9) and uranyl nitrate-induced acute renal failure (U-ARF, n = 12) rats, or male Sprague-Dawley rats fed on a 23% (control, n = 8) or a 5% (protein-calorie malnutrition, PCM, n = 9) protein diet. After i.v. administration of DA-125, almost 'constant' plasma concentrations of M1, M2, and M4 were maintained from 1-2 h to 8-10 h in all rat groups due to the continuous formation of M2 from M1 and M4 from M3. The plasma concentrations of M3 were the lowest among M1-M4 for all rat groups due to the rapid and almost complete conversion of M3 to M4 and other metabolite(s). The AUCt values of M1 (115 against 82.5 micrograms min mL-1), M2 (33.0 against 23.6 micrograms min mL-1), and M4 (26.3 against 15.1 micrograms min mL-1) were significantly higher in the U-ARF rats than in the control rats. The percentages of i.v. dose excreted in 24 h urine as M1 (under the detection limit against 0.316%), M2 (under the detection limit against 5.58%), and M4 (0.0174 against 0.719%)--expressed in terms of DA-125--were significantly lower in the U-ARF rats than in the control rats, and this could be due to the decreased kidney function in the U-ARF rats. However, the percentages of i.v. dose recovered from the GI tract at 24 h as M1 (0.0532% against under the detection limit), M3 (0.0286% against under the detection limit), and M4 (0.702% against 0.305%)--expressed in terms of DA-125--were significantly greater in the U-ARF rats than in the control rats. All U-ARF rats had ascites, but the concentrations of M1 (0.0320 micrograms mL-1), M2 (0.0265 micrograms mL-1), M3 (under the detection limit), and M4 (0.032 micrograms mL-1) in the ascites from one rat were almost negligible. The plasma concentrations and most of the pharmacokinetic parameters of M1, M2, and M4 were not significantly different between the PCM rats and their control rats.
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Affiliation(s)
- Y G Kim
- College of Pharmacy, Seoul National University, Korea
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Pérez-Pinzón MA, Maier CM, Yoon EJ, Sun GH, Giffard RG, Steinberg GK. Correlation of CGS 19755 neuroprotection against in vitro excitotoxicity and focal cerebral ischemia. J Cereb Blood Flow Metab 1995; 15:865-76. [PMID: 7673380 DOI: 10.1038/jcbfm.1995.108] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The in vivo neuroprotective effect and brain levels of cis-4-phosphonomethyl-2-piperidine carboxylic acid (CGS 19755), a competitive N-methyl-D-aspartate (NMDA) antagonist, were compared with its in vitro neuroprotective effects. The dose-response for in vitro neuroprotection against both NMDA toxicity and combined oxygen-glucose deprivation (OGD) was determined in murine neocortical cultures. Primary cultures of neocortical cells from feta mice were injured by exposure to 500 microM NMDA for 10 min or to OGD for 45 min. The effect of CGS 19755 in both injury paradigms was assessed morphologically and quantitated by determination of lactate dehydrogenase release. Near complete neuroprotection was found at high doses of CGS 19755. The ED50 for protection against NMDA toxicity was 25.4 micro M, and against OGD the ED50 was 15.2 microM. For the in vivo paradigm rabbits underwent 2 h of left internal carotid, anterior cerebral, and middle cerebral artery occlusion followed by 4 h reperfusion; ischemic injury was assessed by magnetic resonance imaging and histopathology. The rabbits were treated with 40 mg/kg i.v. CGS 19755 or saline 10 min after arterial occlusion. CSF and brain levels of CGS 19755 were 12 microM and 5 microM, respectively, at 1 h, 6 microM and 5 microM at 2 h, and 13 microM and 7 microM at 4 h. These levels were neuroprotective in this model, reducing cortical ischemic edema by 48% and ischemic neuronal damage by 76%. These results suggest that a single i.v. dose penetrates the blood-brain barrier, attaining sustained neuroprotective levels that are in the range for in vitro neuroprotection.
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Affiliation(s)
- M A Pérez-Pinzón
- Department of Neurosurgery, Stanford University Medical Center, California, USA
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Steinberg GK, Yoon EJ, Kunis DM, Sun GH, Maier CM, Grant GA. Neuroprotection by N-methyl-D-aspartate antagonists in focal cerebral ischemia is dependent on continued maintenance dosing. Neuroscience 1995; 64:99-107. [PMID: 7708219 DOI: 10.1016/0306-4522(94)00374-e] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
While N-methyl-D-aspartate antagonists have been shown to attenuate neuronal damage in focal cerebral ischemia, few studies have examined whether continuous or multiple dose treatment is necessary for maximum efficacy. We studied the effect of a loading dose only or load plus maintenance infusion using several non-competitive N-methyl-D-aspartate antagonists (dextromethorphan, dextrorphan, MK-801) and the levorotatory enantiomer of dextromethorphan (levomethorphan) in a rabbit model of focal cerebral ischemia. Forty-seven anesthetized rabbits underwent occlusion of the left internal carotid, anterior cerebral and middle cerebral arteries for 2 h followed by 4 h of reperfusion. Drugs were administered 10 min after occlusion. Dextromethorphan and dextrorphan protected against ischemic edema only when given as load plus maintenance (29% and 31% reduction, respectively), while both load only and load plus maintenance of MK-801 protected against edema (26% and 31% reduction, respectively). Levomethorphan load plus maintenance also protected against ischemic edema (25% reduction). However, dextromethorphan and dextrorphan both required maintenance infusion to protect against ischemic neuronal damage (24% and 27% reduction in area of ischemic neuronal damage, respectively), while levomethorphan failed to protect against neuronal injury even when given as load plus maintenance. Administration of MK-801 as load plus maintenance reduced ischemic neuronal damage by 23%, but this difference was not quite statistically significant. These results suggest that processes of ischemic damage, such as excitotoxic injury, continue for several hours beyond the initial period of focal ischemia, and that non-competitive N-methyl-D-aspartate antagonists require more prolonged administration to achieve neuroprotection.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- G K Steinberg
- Department of Neurosurgery, Stanford University School of Medicine, CA 94305, USA
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Park JM, Ahn BN, Yoon EJ, Lee MG, Shim CK, Kim CK. The pharmacokinetics of methotrexate after intravenous administration of methotrexate-loaded proliposomes to rats. Biopharm Drug Dispos 1994; 15:391-407. [PMID: 7981428 DOI: 10.1002/bdd.2510150506] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The pharmacokinetics and tissue distribution of methotrexate (MTX) were investigated after intravenous (i.v.) injection of free MTX (treatment I), MTX-loaded proliposomes (treatment II), and empty proliposomes mixed manually with free MTX (treatment III), 8 mg kg-1, to rats using an HPLC assay. After i.v. infusion in 1 min, the plasma concentration of MTX (Cp), the area under the plasma concentration-time curve (AUC, 639 versus 913 micrograms min mL-1), the terminal half-life (t1/2, 48.8 versus 397 min), the mean residence time (MRT, 8.40 versus 325 min), and the apparent volume of distribution at steady state (Vss, 98.1 versus 2800 mL kg-1) were significantly higher; however, the total body clearance (CL, 12.5 versus 8.76 mL min-1 kg-1), renal clearance (CLR, 4.49 versus 2.78 mL min-1 kg-1), non-renal clearance (CLNR, 7.50 versus 5.99 mL min-1 kg-1), and the amount of MTX excreted in urine (Xu, 808 versus 685 micrograms, p < 0.0948) were significantly lower from treatment II than from treatment I. This could be due to the fact that some of the MTX-loaded liposomes (formed immediately after hydration of MTX-loaded proliposomes) are entrapped in tissues and the rest are present in the plasma (higher MRT and Vss from treatment II), and MTX is slowly released from MTX-loaded liposomes (higher t1/2 from treatment II). In the present HPLC assay, the concentrations of MTX represent the sum of free MTX and MTX loaded in liposomes (higher Cp and AUC, slower CL from treatment II). After i.v. infusion in 1 min, some pharmacokinetic parameters, such as t1/2, MRT, and Vss, were significantly different between treatments I and III; however, the differences seemed to be smaller than those between treatments I and II. After 30 min from i.v. infusion, the tissue to plasma (T/P) ratios of MTX in kidney and stomach from treatment II were significantly lower than those from treatment I. This suggested that the i.v. administration of MTX-loaded proliposomes might have fewer side effects in the organs than that of free MTX. The mean amount of MTX loaded in MTX-loaded proliposomes was 2.54 mg/g proliposomes and the MTX was released slowly from hydrated MTX-loaded proliposomes when incubated with phosphate-buffered saline (PBS), rat plasma, or rat liver homogenate.
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Affiliation(s)
- J M Park
- College of Pharmacy, Seoul National University, Korea
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Shim HJ, Lee ED, Yoon EJ, Lee SD, Kim WB, Yang J, Lee MG. Simultaneous determination of a new anthracycline, DA-125, and its metabolites M1, M2, M3 and M4 in plasma and urine by high-performance liquid chromatography. J Chromatogr B Biomed Appl 1994; 656:407-14. [PMID: 7987494 DOI: 10.1016/0378-4347(94)00105-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
A high-performance liquid chromatographic method was developed for the simultaneous determination of a new anthracycline, DA-125 (I), and its metabolites (M1, M2, M3, and M4) in rat plasma and urine using fluorescein as an internal standard. Compound I, a prodrug of M1, is a beta-alanine derivative of M1, and only M1 shows antineoplastic activity. The method involved extraction or deproteinization followed by injection of 80-100 microliters of the aqueous layer or supernatant onto a C18 reversed-phase column. The mobile phases were 1% acetic acid-isopropyl alcohol-methanol (70:20:10, v/v) or 5 mM of ion-pairing chromatography reagent (IPC B8)-isopropyl alcohol-methanol (70:20:10, v/v) for the extraction or deproteinization methods, respectively. The flow-rate was 1.5 ml/min for both methods. The column effluent was monitored by a fluorescence detector with excitation wavelength of 488 nm and emission wavelength of 556 nm. The detection limits for M1, M2, M3, and M4 in rat plasma and urine were 50 ng/ml for all compounds using the extraction method, and 100, 50, 50, 50, and 50 ng/ml for I, M1, M2, M3 and M4 in rat plasma respectively, using the deproteinization method. No interferences from endogenous substances, adriamycin or daunorubicin were found.
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Affiliation(s)
- H J Shim
- Research Laboratory, Dong-A Pharmaceutical Company, Ltd., Kyunggi-Do, South Korea
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