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Biomedical subjects

W B Kim

Publications and source records attributed to W B Kim.

At least 55 records · Page 3Linked to original sources

Thyroglobulin regulates follicular function and heterogeneity by suppressing thyroid-specific gene expression.

Thyroglobulin (TG) is the primary synthetic product of the thyroid and the macromolecular precursor of thyroid hormones. TG synthesis, iodination, storage in follicles, and lysosomal degradation can each modulate thyroid hormone formation and secretion into the circulation. Thyrotropin (TSH), via its receptor (the TSHR), increases thyroid hormone levels by upregulating expression of the sodium iodide symporter (NIS), thyroid peroxidase (TPO), and TG genes. TSH does this by modulating the expression and activity of the thyroid-specific transcription factors, thyroid transcription factor (TTF)-1, TTF-2, and Pax-8, which coordinately regulate NIS, TPO, TG, and the TSHR. Major histocompatibility complex (MHC) class I gene expression, which is also regulated by TTF-1 and Pax-8 in the thyroid, is simultaneously decreased; this maintains self tolerance in the face of TSH-increased gene products necessary for thyroid hormone formation. We now show that follicular TG, 27S > 19S > 12S, counter-regulates TSH-increased thyroid-specific gene transcription by suppressing the expression of the TTF-1, TTF-2, and Pax-8 genes. This decreases expression of the TG, TPO, NIS and TSHR genes, but increases class I expression. TG action involves an apical membrane TG-binding protein; however, it acts transcriptionally, targeting, for example, a sequence within 1.15 kb of the start of TTF-1 transcription. TG does not affect ubiquitous transcription factors regulating TG, TPO, NIS and/or TSHR gene expression. TG activity is not duplicated by thyroid hormones or iodide. We hypothesize that TG-initiated, transcriptional regulation of thyroid-restricted genes is a normal, feedback, compensatory mechanism which regulates follicular function, regulates thyroid hormone secretion, and contributes to follicular heterogeneity.

Animals↗

Two Graves' disease patients who spontaneously developed hypothyroidism after antithyroid drug treatment: characteristics of epitopes for thyrotropin receptor antibodies.

Few reports have identified blocking thyrotropin receptor antibodies (TSHRAbs) as a pathogenic mechanism explaining spontaneous hypothyroidism after antithyroid drug (ATD) treatment of Graves' disease. Here we report 2 Graves' patients who showed different courses of hypothyroidism after ATD treatment. The first patient had Graves' hyperthyroidism and was treated with ATD for 1 year. After a short period of euthyroidism, she developed permanent hypothyroidism with blocking TSHRAb. The second patient became euthyroid after 1 year of ATD treatment. After 3 years, however, she presented with hypothyroidism with blocking TSHRAb activity. Her hypothyroidism was transient, and restoration of euthyroidism was followed by disappearance of blocking TSHRAb. Blocking and stimulating TSHRAbs activities of these 2 patients were serially measured using Chinese hamster ovary (CHO) cells transfected with wild-type human TSHR (CHO-hTSHR) and 2 TSHR chimeras with residues 8-165 (Mc1+2) or 90-165 (Mc2) substituted by equivalent residues of the luteinizing hormone/chorionic gonadotropin receptor (LH/CGR). During their hypothyroid phases, blocking TSHRAbs activities were positive in all 3 kinds of assays and stimulating TSHRAbs activities were negative in CHO-hTSHR or in Mc 1+2 assay. Mc2 stimulating TSHRAb activity was detected in sera of hypothyroid phase of the second patient who had transient hypothyroidism but not in the first whose hypothyroidism was permanent. In these 2 cases, we demonstrate the causative role of blocking TSHRAb in the development of hypothyroidism after ATD treatment in Graves' patients. Interestingly, the difference in the course of blocking TSHRAb-induced hypothyroidism was associated with the difference in epitope reactivities of TRAb during hypothyroid phase that developed after ATD treatment of Graves' disease.

Adult↗

Effect of probenecid on the renal excretion mechanism of a new carbapenem, DA-1131, in rats and rabbits.

The effects of probenecid, an anion transport inhibitor, on the renal excretion mechanism of a new anionic carbapenem, DA-1131, were investigated after a 1-min intravenous infusion of DA-1131 at 100 mg/kg of body weight to rabbits and 50 mg/kg to rats with or without probenecid at 50 mg/kg for both species. In control rabbits, the renal clearance (CLR) of DA-1131 and the glomerular filtration rate based on creatinine clearance (CLCR) were 6.14 +/- 2.09 and 2.26 +/- 0.589 ml/min/kg, respectively. When considering the less than 10% plasma protein binding of DA-1131 in rabbits, renal tubular secretion of DA-1131 was observed in rabbits. The CLR of DA-1131 (3. 87 +/- 0.543 ml/min/kg) decreased significantly with treatment with probenecid in rabbits, indicating that the renal tubular secretion of DA-1131 was inhibited by probenecid. However, in control rats, the CLR of DA-1131 (5.80 +/- 1.94 ml/min/kg) was comparable to the CLCR (4.29 +/- 1.64 ml/min/kg), indicating that DA-1131 was mainly excreted by glomerular filtration in rats. Therefore, it could be expected that the CLR of DA-1131 could not be affected by treatment with probenecid in rats; this was proved by a similar CLR of DA-1131 with treatment with (6.93 +/- 0.675 ml/min/kg) or without (5.80 +/- 1.94 ml/min/kg) probenecid. Therefore, the renal secretion of DA-1131 is a factor in rabbits but is not a factor in rats.

Animals↗

Effects of cilastatin on the pharmacokinetics of a new carbapenem, DA-1131, in rats, rabbits, and dogs.

DA-1131, a new carbapenem antibiotic, undergoes renal metabolism by renal dehydropeptidase I (DHP-I), located on the brush border of the proximal tubular cell. Species differences with regard to the effects of cilastatin, a renal DHP-I inhibitor, were investigated after a 1-min intravenous infusion of DA-1131, with or without cilastatin, to rats, rabbits, and dogs. After intravenous infusion, the nonrenal clearance (CL(NR)) of DA-1131 was significantly slower in rats (3.00 versus 8.01 ml/min/kg) and rabbits (2.41 versus 6.77 ml/min/kg) when the drug was coadministered with cilastatin; this could be due to the slower metabolism of DA-1131 by rat and rabbit kidney DHP-I. This indicated that renal metabolism of DA-1131 by renal DHP-I was inhibited by cilastatin. However, coadministration with cilastatin to dogs did not affect the CL(NR) of DA-1131.

Animals↗

Pharmacokinetic changes of a new carbapenem, DA-1131, after intravenous administration to spontaneously hypertensive rats and deoxycorticosterone acetate-salt-induced hypertensive rats.

The pharmacokinetics of a new carbapenem, DA-1131, were compared after i.v. administration of the drug, 50 mg/kg, to spontaneously hypertensive rats (SHRs) at 16 weeks of age (an animal model for human primary hypertension) and at 6 weeks of age (corresponding to the early phase of the development of hypertension, at which time blood pressure remains within the normotensive range) and their respective age-matched control normotensive Kyoto-Wistar rats (KW rats), and deoxycorticosterone acetate-salt-induced hypertensive rats at 16 weeks of age (an animal model for human secondary hypertension) and their age-matched control Sprague-Dawley rats. The total area under the plasma concentration-time curve from time zero to time infinity (AUC) (4720 versus 7070 microg x min/ml) was significantly smaller, and the nonrenal clearance (CLNR) (5.37 versus 3.57 ml/min/kg) was significantly faster in 16-week-old SHRs than those in their control KW rats. Similar results were also obtained from 6-week-old SHRs in AUC (3800 versus 4680 microg x min/ml) and CLNR (7.73 versus 3.31 ml/min/kg). However, the values were reversed in 16-week-old deoxycorticosterone acetate-salt rats in AUC (5310 versus 3870 microg.min/ml) and CLNR (2.57 versus 4.90 ml/min/kg). The significantly faster CLNR of DA-1131 in both 6- and 16-week-old SHRs could be supported at least partly by the results of the in vitro metabolism with kidney homogenate and considerably greater total renal dehydropeptidase-I activity. The data above indicated that the significantly faster CLNR of DA-1131 in 16-week-old SHRs than that in their age-matched control KW rats was due to any hereditary characteristics of SHRs and was not due to the hypertensive state itself.

Animals↗

Pharmacokinetics of a non-narcotic analgesic, DA-5018, in rats.

The pharmacokinetics of a non-narcotic analgesic, DA-5018, were compared after single intravenous (i.v.), subcutaneous (s.c.), and oral administrations, and after multiple (seven consecutive days) s.c. administration to rats. After i.v. administration of DA-5018, 1, 2, and 5 mg kg-1, the pharmacokinetic parameters of DA-5018 were independent of the dose ranges studied. After oral administration of DA-5018, absorption of the drug from gastrointestinal (GI) tract was fast, but the extent of absolute bioavailability (F) was low; the values were 23.2, 23.0, and 27.3% for 2, 5, and 10 mg kg-1, respectively. After single s.c. administration of DA-5018, absorption of the drug from the injected site was fast and the extent of absorption was fairly good; the F values were 74.5 and 71.8% for 2 and 5 mg kg-1, respectively. The lower F values after oral administration of DA-5018 to rats could be due to degradation of the drug in rat GI tract and/or considerable first-pass effect. After i.v., oral, and s.c. administration of DA-5018, the drug had a strong affinity to the rat tissues studied as reflected in the greater-than-unity tissue to plasma ratio. After i.v., oral, and s.c. administration of the drug, the biliary and urinary excretion of unchanged DA-5018 were negligible. There was no significant difference in the pharmacokinetics or tissue distribution of DA-5018 between single and multiple s.c. administration of the drug, 5 mg kg-1, to rats, indicating that there could be no tissue accumulation of the drug after multiple s.c. administration of the drug to rats.

Administration, Oral↗

Pharmacokinetic changes of M1, M2, M3 and M4 after intravenous administration of a new anthracycline, DA-125, to rats pretreated with phenobarbital, 3-methylcholanthrene, chloramphenicol, or SKF-525A.

The pharmacokinetics of M1-M4, the metabolites of a new anthracycline antineoplastic agent, DA-125, were compared after intravenous (i.v.) administration of DA-125, 15 mg kg-1, to rats pretreated with enzyme inducers, such as phenobarbital (PBT, n = 14) and 3-methylcholanthrene (MCT, n = 15), or enzyme inhibitors, such as SKF-525A (SKT, n = 11) and chloramphenicol (CMT, n = 15), and to their control rats (n = 15 for PBC, CMC or SKC, and n = 11 for MCC). After i.v. administration of DA-125, the plasma concentrations of both M1 and M2 declined slowly from 1 to 2 h onwards to 8 h in all groups of rats due to the continuous formation of M2 from M1. The AUC0-8 h of M1 (47.1 versus 7.85 micrograms min mL-1) and M2 (20.7 versus 44.3 micrograms min mL-1) decreased significantly in the PBT group compared to those in the PBC group. However, the corresponding value of only M1 (74.6 versus 89.9 micrograms min mL-1) decreased significantly in the MCT group. The above data indicate that metabolism of M1 is increased by pretreatment with both PB and 3-MC, and that of M2 with PB, but not with 3-MC. The AUC0-8 h of both M1 (126 versus 78.5 micrograms min mL-1) and M2 (69.2 versus 44.3 micrograms min mL-1) increased significantly in the SKT group compared to the SKC group. However, the corresponding values were not significantly different between CMC and CMT groups. The above data indicate that the metabolism of both M1 and M2 is inhibited by pretreatment with SKF-525A, but not with CM.

Animals↗

Interspecies pharmacokinetic scaling of a new carbapenem, DA-1131, in mice, rats, rabbits and dogs, and prediction of human pharmacokinetics.

The total body clearance (CI), renal clearance (CIr), and apparent volume of distribution at steady state (Vss) of DA-1131, a new carbapenem, after intravenous (iv) administration of the drug, 50 mg kg-1, to mice, rats, rabbits, and dogs were analysed as a function of species body weight (W) using the allometric equation for interspecies scaling, and were used to predict these parameters in humans. Significant linear relationships were obtained between log[CI (L h-1)] and log[W (kg)] (r = 0.995; p = 0.00503), log [CI, (L h-1)] and log [W (kg)] (r = 0.998; p = 0.0429), and log [Vss (L)] and log [W (kg)] (r = 0.987; p = 0.0126). The corresponding allometric equations were CI = 0.706W 0811, CIr = 0.318W 0.888, an V88 = 0.194W 0981. These allometric equations were extrapolated to predict the CI and Vss for DA-1131 in humans based on 70 kg body weight. The CI and Vss for humans predicted from the four animal data well fitted to regression lines of animal data. Interspecies scale-up of plasma concentration-time data for the four species using a complex Dedrick plot resulted in similar profiles. In addition, the concentration in plasma-time profile predicted that the DA-1131 data obtained from laboratory animals could be utilized to generate preliminary estimates of the pharmacokinetic parameters in humans. These parameters can serve as guidelines for better planning of clinical studies.

Animals↗

Pharmacokinetics of a new carbapenem, DA-1131, after intravenous administration to rats with alloxan-induced diabetes mellitus.

Because physiological changes occurring in diabetes patients could alter the pharmacokinetics of drugs used to treat the disease, the pharmacokinetics and tissue distribution of DA-1131, a new carbapenem antibiotic, were investigated after 1-min intravenous (i.v.) administration of the drug, 50 mg kg-1, to control and alloxan-induced diabetes mellitus (AIDM) rats. The impaired kidney function was observed by pretreatment with alloxan based on physiological parameters of plasma, creatinine clearance, and the kidney microscopy. After 1-min i.v. infusion of DA-1131, the plasma concentrations of DA-1131 and the total area under the plasma concentration-time curve of DA-1131 from time zero to time infinity (AUC) increased significantly in the AIDM rats (7350 versus 4400 micrograms min mL-1) when compared with those in control rats. This was due to significantly slower total body clearance (Cl) of DA-1131 (6.80 versus 11.4 mL min-1 kg-1) in AIDM rats than that in control rats. The significantly slower Cl of DA-1131 in AIDM rats was due to significantly slower renal (2.62 versus 4.95 mL min-1 kg-1, because of the considerably decreased glomerular filtration rate of DA-1131) and nonrenal (3.99 versus 6.34 mL min-1 kg-1, possibly because of the considerably slower metabolism in rat liver and kidney) clearance in AIDM rats. The amount of DA-1131 recovered from each rat tissue studied was significantly higher in AIDM rats than that in control rats, however, the tissue to plasma ratios were not significantly different between the two groups of rats.

Alloxan↗

Taurine can ameliorate inflammatory bowel disease in rats.

We previously reported that the protective effect of taurine against indomethacin-induced gastric mucosal injury was due to its antioxidant effects which inhibited lipid peroxidation and neutrophil activation. In this study, we examined the effect of taurine on reducing the inflammatory parameters of trinitrobenzene sulfonic acid (TNBS)-induced inflammatory bowel disease (IBD) in rats. To induce IBD, rats were given ethanolic TNBS intracolonically. The rats then received 500 mg/kg/day of taurine per orally. The rats were sacrificed one week after IBD induction. Ulceration and inflammation of the distal colon with formation of granuloma in the vehicle-treated IBD rats after two days of administration of TNBS were observed. Treatment with 0.5 g/kg of taurine by the oral route ameliorated colonic damage and decreased the incidence of diarrhea and adhesions. Colon weight (an index of tissue edema) was markedly increased in the IBD rats after administration of TNBS, but was significantly lower after taurine treatment. Myeloperoxidase (MPO) activity in the vehicle-treated IBD rats was substantially increased compared with that of the control. The taurine-treated animals showed reduced MPO activity (35% lower) when compared with that of the vehicle-treated animals. Taurine treatment decreased basal and formyl-methionyl leucyl phenylalanine (FMLP) stimulated reactive oxygen generation in colonic tissue of the IBD rat compared with vehicle treatment after one week. These results suggest that administration of taurine reduced the inflammatory parameters in this rat model of IBD by increasing the defenses against oxidative insult.

Animals↗

Studies on protective effect of DA-9601, Artemisia asiatica extract, on acetaminophen- and CCl4-induced liver damage in rats.

The hepatoprotective effect of DA-9601, a quality-controlled extract of Artemisia asiatica, on liver damage induced by acetaminophen (APAP) and carbon tetrachloride (CCl4) was investigated by means of serum-biochemical, hepatic-biochemical, and histopathological examinations. Doses of DA-9601 (10, 30, or 100 mg/kg) were administered intragastrically to each rat on three consecutive days i.e. 48 h, 24 h and 2 h before a single administration of APAP (640 mg/kg, i.p.) or CCl4 (2 ml/kg, p.o.). Four h and 24 h after hepatotoxin treatment, the animals were sacrificed for evaluation of liver damage. Pretreatment of DA-9601 reduced the elevation of serum ALT, AST, LDH and histopathological changes such as centrilobular necrosis, vacuolar degeneration and inflammatory cell infiltration dose-dependently. DA-9601 also prevented APAP- and CCl4-induced hepatic glutathione (GSH) depletion and CCl4-induced increase of hepatic malondialdehyde (MDA), a parameter of lipid peroxidation, in a dose-dependent manner. These findings suggest that pretreatment with DA-9601 may reduce chemically induced liver injury by complex mechanisms which involve prevention of lipid peroxidation and preservation of hepatic GSH.

Acetaminophen↗

Protective effect of taurine on TNBS-induced inflammatory bowel disease in rats.

We had previously reported that the protective effect of taurine against indomethacin-induced gastric mucosal injury was due to its antioxidant effects, which inhibited lipid peroxidation and neutrophil activation. In this study, we examined the effect of taurine on reducing the inflammatory parameters of trinitrobenzene sulfonic acid (TNBS)-induced inflammatory bowel disease (IBD) in rats. In order to induce IBD, ethanolic TNBS was given to rats intracolonically. Then they received 500 mg/kg/day of taurine orally and were sacrificed one week after IBD induction. While ulceration and inflammation of distal colon with formation of granuloma in the vehicle-treated IBD rats two days after administration of TNBS were observed, treatment with taurine ameliorated colonic damage and decreased the incidence of diarrhea and adhesion. Also, colon weight as an index of tissue edema, which was markedly increased in the IBD rats, became significantly lower after taurine treatment. Myeloperoxidase (MPO) activity in the vehicle-treated IBD rats was substantially increased, compared with that of normal control. The taurine-treated animals significantly reduced MPO activity (35% lower) when compared with that of the vehicle-treated animals. Taurine treatment decreased both basal and formyl-methionyl leucyl phenylalanine-stimulated reactive oxygen generation from colonic tissue in the IBD rats. These results suggest that the administration of taurine reduce the inflammatory parameters in this IBD rat model by increasing defending capacity against oxidative damage.

Animals↗

Induction of apoptosis with an extract of Artemisia asiatica attenuates the severity of cerulein-induced pancreatitis in rats.

The aim of this study was to test the hypothesis that apoptosis can protect against experimental pancreatitis and induction of apoptosis by an extract of Artemisia asiatica (DA-9601) is beneficial in cerulein-induced pancreatis in rats. Pancreatitis was induced in 6-week-old male SPF Sprague-Dawley rats by two intravenous (i.v.) administrations of 40 microg/kg cerulein. To investigate the effects of DA-9601 on the severity of pancreatitis and extent of apoptosis, rats were treated with intragastric DA-9601, 30 mg/kg (D30), 100 mg/kg (D100), or 300 mg/kg (D300), intraperitoneal superoxide dismutase, 10,000 U/kg (SOD), and i.v. gabexate mesilate, 40 mg/kg (Foy), three times (30 min before cerulein injection, 30 and 90 min after cerulein injection). The control group was administered vehicle alone. Ten rats were included in each treatment group and control group. Rats were sacrificed 5 h after cerulein treatment. Serum amylase, histological activity index (HAI), pancreatic lipid peroxide levels, and apoptotic index [in situ hybridization by terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end-labeling (TUNEL)] were determined. Gel electrophoresis was performed for the presence of DNA fragmentations. The results were as follows. Serum amylase was significantly increased in all cerulein-treated groups compared to normal controls (p < 0.001). The HAI was significantly decreased in only the D300 group compared to the controls (p < 0.05). The apoptotic index of the cerulein-alone group was 3.8 +/- 2.7, but the mean apoptotic indexes of the SOD and Foy groups were 16.4 +/- 4.6 and 13.3 +/- 1.8, respectively, a significant increase (p < 0.01). The apoptotic index was more significantly increased in the DA-9601-treated groups, dose dependently (8.4 +/- 3.4 in D30, 14.8 +/- 4.3 in D100, 24.2 +/- 4.7 in D300). A smearing pattern of DNA electrophoresis was noted in the DA-9601-treated groups. In conclusion, DA-9601, an extract of Artemisia, induced apoptosis of pancreatic acinar cells dose dependently and concomitantly attenuated the severity of pancreatitis.

Acute Disease↗

Pharmacokinetics of a new carbapenem, DA-1131, after intravenous administration to rats with uranyl nitrate-induced acute renal failure.

Because the physiological changes that occur in patients with acute renal failure could alter the pharmacokinetics of the drugs used to treat the disease, the pharmacokinetics of DA-1131, a new carbapenem antibiotic, were investigated after 1-min intravenous administration of the drug (50 mg/kg of body weight) to control rats and rats with uranyl nitrate-induced acute renal failure (U-ARF rats). The impaired kidney function was observed in U-ARF rats on the basis of physiological parameters observed by microscopy of the kidney and obtained by chemical analysis of the plasma. After a 1-min intravenous infusion of DA-1131, the concentrations in plasma and the total area under the plasma concentration-time curve from time zero to time infinity increased significantly in U-ARF rats compared with those in control rats (13,000 versus 4,400 microg x min/ml). This was due to the significantly slower total body clearance (CL) of DA-1131 (3.84 versus 11.4 ml/min/kg) from U-ARF rats than from control rats. The significantly slower CL of DA-1131 from U-ARF rats was due to both significantly slower renal clearance (0.000635 versus 4.95 ml/min/kg because of a significant decrease in the 8-h urinary excretion of unchanged DA-1131 [1.54 versus 43.8% of the intravenous dose] due to impaired kidney function, as proved by the significant decrease in creatinine clearance [0.0159 versus 4.29 ml/min/kg]) and significantly slower nonrenal clearance (3.80 versus 6.34 ml/min/kg because of a significant decrease in the metabolism of DA-1131 in the kidney) in U-ARF rats. The amounts of DA-1131 recovered from all tissues studied (except the kidneys) were significantly higher for U-ARF rats than for control rats; however, the ratios of the amount in tissue to the concentration in plasma (except those for the kidney, small intestine, and spleen) were not significantly different between the two groups of rats, indicating that the affinity of DA-1131 for rat tissues was not changed considerably in U-ARF rats.

Acute Kidney Injury↗

A new point mutation (3426, A to G) in mitochondrial NADH dehydrogenase gene in Korean diabetic patients which mimics 3243 mutation by restriction fragment length polymorphism pattern.

Mitochondrial tRNA(Leu)(UUR) gene mutation is one of the candidates in the pathogenesis of NIDDM. Especially the 3243 (A-->G) mutation is associated with the maternally-inherited diabetes and deafness. To evaluate the prevalence and characteristics of the 3243 point mutation in Koreans, we screened 433 Korean diabetic patients (220 men and 213 women). Genomic DNA was extracted from peripheral white blood cells and PCR was carried out with mitochondrial DNA primers (3130-3149, 3558-3539) encompassing the 3243 position. After digestion with Apa-1, five subjects showed polymorphism suggesting 3243 point mutation but when we directly sequenced the amplified DNA with an automatic sequencer, only 2 of the 5 patients were shown to have 3243 (A-->G) mutation and the other 3 subjects had 3426 (A-->G) mutation rather than 3243 mutation. Two diabetic patients with 3243 mutation were lean (BMI = 14.4, 17.0 kg/m2), had relatively lower fasting C-peptide concentrations (0.9 ng/ml each), and required insulin for management. In contrast, those with 3426 point mutation were not lean (BMI = 22.6-28.0 kg/m2), had relatively higher C-peptide levels (3.9-5.4 ng/ml), and could be managed with oral hypoglycemic agents. None of the 5 patients had deafness. In conclusion, the prevalence of 3243 point mutation in Korean diabetic patients was approximately 0.5% and we found a new mutation mimicking 3243 mutation by PCR-RFLP (restriction fragment length polymorphism) pattern. We suggest that sequencing of the PCR product or designing smaller PCR fragment size to enhance the specificity may help to identify the exact location of the point mutation.

Adult↗

Phase I clinical trial: pharmacokinetics of a novel anthracycline, DA-125 and metabolites. Single dose study.

Single dose of DA-125, 20 (n = 3), 40 (n = 3), 60 (n = 3), 80 (n = 6), or 100 (n = 6) mg/m2 body surface area, was administered intravenously in 5 min to 21 patients with various types of cancer as phase I clinical trial. The main side-effects of DA-125 were nausea, vomiting, leukopenia (especially neutropenia), and thrombocytopenia. Among those, hematological side-effects increased with increased doses of DA-125. No patient developed side-effects equal to or higher than grade III up to DA-125 dose of 60 mg/m2. However, at DA-125 dose of 80 mg/m2, 1 out of 3 patients developed grade III leukopenia and grade IV neutropenia. Therefore, 3 additional patients participated taking the dose of 80 mg/m2; no patient developed side-effects equal to or higher than grade III. Hence, DA-125 dose increased to 100 mg/m2. At DA-125 dose of 100 mg/m2, 2 out of 3 patients developed side-effects equal to or higher than grade III and, therefore, 3 additional patients participated taking this dose. Among the 3 additional patients, 1 patient developed both grade III leukopenia and neutropenia. Therefore, further accrual was stopped at this dose (100 mg/m2). The maximally tolerated dose (MTD) of DA-125 was determined to be 100 mg/m2, and the dose-limiting factor for DA-125 was bone marrow suppression. DA-125 dose of 80 mg/m2, 80% of MTD of DA-125, was recommended as the dose for phase II clinical trial. Cardiotoxicity was not observed in any of the 21 patients according to the ECG and RVG. Neither fever, stomatitis, diarrhea, and renal and nervous system toxicity, nor abnormality in blood coagulation was observed in any of the patients, and death or life-threatening side-effects due to DA-125 were also not observed. Antitumor effects of DA-125 were evaluated from the 21 patients; 6 progressive disease, 14 stable disease, and 1 partial response. Pharmacokinetic parameters of M1, such as AUC, t1/2, CL, VSS, and MRT, seemed to be independent of i.v. doses of DA- 125, 20-100 mg/m2 and less than 0.75% of M1 were excreted in 96 h urine when expressed in terms of DA-125 i.v. dose. M2 was the main metabolite of DA-125 among M1-M4 excreted in urine; 10.1 approximately 22.3% of M2 was excreted in 96 h urine when expressed in terms of DA-125 i.v. dose. Bile was collected via the T-tube in 1 additional patient at the dose of 100 mg/m2. Biliary excretion of M1 and M2 was negligible; less than 0.320 and 4.76% of M1 and M2, respectively, were excreted in 96 h bile when expressed in terms of DA-125 i.v. dose.

Adult↗

No effect of probenecid on the renal excretion mechanism of a new carbapenem, DA-1131, in dogs.

The effect of probenecid, an anion transport inhibitor, on the renal excretion mechanism of a new anionic carbapenem, DA-1131, was investigated after 1-min intravenous infusion of DA-1131, 10 mg/kg, with or without probenecid, 50 mg/kg, to dogs. The renal clearance (CL(R)) of DA-1131 in dogs without probenecid (3.18+/-0.247 ml/min/kg) was considerably smaller than the reported creatinine clearance (CL(CR)) in dogs, 6.13 ml/min/kg, indicating that renal tubular reabsorption of the drug was observed in dogs. However, the CLR of DA-1131 was not significantly different (3.18+/-0.247 versus 3.29+/-0.698 ml/min/kg) by treatment with probenecid indicating that the tubular reabsorption of DA-1131 was not inhibited by probenecid.

Absorption↗

Determination of a new non-narcotic analgesic, DA-5018, in plasma, urine and bile by high-performance liquid chromatography.

A high-performance liquid chromatographic method was developed for the determination of a new non-narcotic analgesic, DA-5018 (I), in rat plasma, urine and bile samples, using propranolol for plasma samples and protriptyline for urine and bile samples as internal standards. The method involved extraction followed by injection of 100 microliters of the aqueous layer onto a C18 reversed-phase column. The mobile phases were 5 mM methanesulfonic acid with 10 mM NaH2PO4 (pH 2.5)-acetonitrile, 70:30 (v/v) for plasma samples and 75:25 (v/v) for urine and bile samples. The flow-rates were 1.0 ml/min for plasma samples and 1.2 ml/min for urine and bile samples. The column effluent was monitored by a fluorescence detector with an excitation wavelength of 270 nm and an emission wavelength of 330 nm. The retention time for I was 4.8 min in plasma samples and 10.0 min in urine and bile samples. The detection limits for I in rat plasma, urine and bile were 20, 100 and 100 ng/ml, respectively. There was no interference from endogenous substances.

Analgesics, Non-Narcotic↗