Pruni cortex ameliorates skin inflammation possibly through HMGB1-NFκB pathway in house dust mite induced atopic dermatitis NC/Nga transgenic mice.

Pruni cortex, the bark of Prunus jamasakura Siebold ex Koidzumi, has been used in the Japanese systems of medicine for many years for its anti-inflammatory, antioxidant and antitussive properties. In this study, we investigated the effect of pruni cortex on atopic dermatitis NC/Nga mouse model. Atopic dermatitis-like lesion was induced by the application of house dust mite extract to the dorsal skin. After induction of atopic dermatitis, pruni cortex aqueous extract (1 g/kg, p.o.) was administered daily for 2 weeks. We evaluated dermatitis severity, histopathological changes and cellular protein expression by Western blotting for nuclear and cytoplasmic high mobility group box 1, receptor for advanced glycation end products, nuclear factor κB, apoptosis and inflammatory markers in the skin of atopic dermatitis mice. The clinical observation confirmed that the dermatitis score was significantly lower when treated with pruni cortex than in the atopic dermatitis group. Similarly pruni cortex inhibited hypertrophy and infiltration of inflammatory cells as identified by histopathology. In addition, pruni cortex significantly inhibited the protein expression of cytoplasmic high mobility group box 1, receptor for advanced glycation end products, nuclear p-nuclear factor kappa B, apoptosis and inflammatory markers. These results indicate that pruni cortex may have therapeutic potential in the treatment of atopic dermatitis by attenuating high mobility group box 1 and inflammation possibly through the nuclear factor κB pathway.

Hepatoprotective effect by pretreatment with olprinone in a swine partial hepatectomy model.

Excessive portal flow to a small remnant liver or small-for-size graft is a primary factor of small-for-size syndrome. We demonstrated that olprinone (OLP), a phosphodiesterase III inhibitor, had a hepatoprotective effect in a rat extended hepatectomy model and a small-for-size liver transplantation model through a modification of the portal venous pressure (PVP). To identify the appropriate dose and duration of treatment for clinical applications, we conducted experiments with a swine partial hepatectomy model. Twenty microminipigs were divided into 4 groups that received the following treatments: (A) saline (control group), (B) OLP at 0.3 µg/kg/minute (preoperative and postoperative administration), (C) OLP at 0.1 µg/kg/minute (preoperative administration), and (D) OLP at 0.3 µg/kg/minute (preoperative administration). The pigs underwent 70% partial hepatectomy. Hemodynamic changes, including changes in PVP, were examined. Liver biopsy was performed 1 and 3 hours after hepatectomy. Blood samples were collected until postoperative day 7 (POD7). In comparison with group A, PVP elevations, periportal edema, and sinusoidal hemorrhaging were attenuated after left Glisson's ligation in groups C and D. Pretreatment with OLP in groups C and D preserved the microstructure of sinusoids and improved the prothrombin activity 1 and 3 hours after hepatectomy. These animals showed better recovery of the remnant liver volume and the plasma disappearance rate of indocyanine green on POD7. In contrast, group B showed exacerbation of liver damage. Measurements of the serum OLP concentration showed that 10 ng/mL OLP was appropriate for a hepatoprotective effect. In conclusion, pretreatment with OLP shows hepatoprotective effects in a swine partial hepatectomy model. OLP may have the potential to ameliorate patients' outcomes after hepatectomy or liver transplantation.

Decreased vancomycin clearance in patients with congestive heart failure.

PURPOSE: Congestive heart failure (CHF) alters the pharmacokinetics of various drugs, including cardiovascular agents, due to decreased cardiac output and decreased renal blood flow. The purpose of this study was to evaluate the influence of CHF on the clearance of vancomycin, a glycopeptide antibacterial agent. METHODS: After reviewing more than 1,500 clinical charts of patients who received vancomycin therapy and whose serum vancomycin level was monitored, we identified 101 patients who also had the left ventricular ejection fraction (LVEF) assessed at that time. The fluorescence polarization immunoassay method was used to measure vancomycin serum concentrations in these patients 1 h after the end of vancomycin infusion and just before the next administration. Using these two measurements, we calculated the pharmacokinetic parameters using the Bayesian estimator. RESULTS: Patients with an LVEF of <40 % (16 patients) or those with an LVEF of ≥ 40 % and <60 % (40 % ≤ LVEF < 60 % ; 32 patients) had a significantly lower vancomycin clearance than patients with LVEF of ≥ 60 % (53 patients) (2.29 ± 0.95 or 2.79 ± 0.99 vs. 3.50 ± 1.04 L/h; p < 0.001 or p < 0.01, respectively). Vancomycin clearance was strongly correlated not only with estimated creatinine clearance (CLcr) in patients with an LVEF of <40 % (r = 0.828) and 40 % ≤ LVEF < 60 % (r = 0.773), but also with an LVEF in patients with a CLcr of <60 mL/min (r = 0.646). Consistent with these findings, multiple regression analysis revealed that CLcr, LVEF and body weight were important independent variables for vancomycin clearance (r(2) = 0.649). CONCLUSIONS: Vancomycin clearance decreased with decreasing cardiac function (LVEF) and decreasing CLcr. This finding suggests that vancomycin clearance is affected by cardiac function and would be predicted not only CLcr but also by LVEF.

Population pharmacokinetics of olprinone in patients undergoing cardiac surgery with cardiopulmonary bypass.

PURPOSE: Olprinone, a phosphodiesterase type III inhibitor, is a strong inotrope and vasodilator that does not increase oxygen consumption and is often used during weaning from cardiopulmonary bypass (CPB). To control the pharmacological effects of olprinone, pharmacokinetic information is essential; however, there is little published information on the pharmacokinetics of olprinone in a large population. Therefore, the purpose of this study was to determine olprinone pharmacokinetic parameters in a large population undergoing cardiac surgery with CPB. METHODS: Olprinone was infused at a rate of 0.2 µg/kg/min when weaning from CPB was started. Whole blood samples were periodically obtained to determine the olprinone concentrations using high-performance liquid chromatography. Measured olprinone concentrations were analyzed with a one-compartment model via a population approach. RESULTS: A total of 86 blood samples from 26 patients were used for pharmacokinetic analysis. The calculated clearance, volume of distribution (V(d)), and elimination half-life were 378 ml/min, 40.7 l, and 97.1 min, respectively. Olprinone clearance depended on weight and creatinine clearance, whereas V(d) depended only on weight. CONCLUSION: We investigated the pharmacokinetic parameters of olprinone in patients undergoing cardiac surgery with CPB. Olprinone clearance depended on weight and creatinine clearance, whereas V(d) depended only on weight. When olprinone is infused according to the recommended dosing regimen, it takes more than 60 min to reach the target concentration (20 ng/ml). However, there is a possibility that a lower concentration is sufficient for weaning from CPB in combination with a continuous infusion of dopamine.

The effect of hemodilution by cardiopulmonary bypass on protein binding of olprinone.

PURPOSE: Olprinone is a phosphodiesterase type III inhibitor that is often used to increase cardiac output after cardiopulmonary bypass (CPB). Hemodilution by CPB is likely to decrease total olprinone concentration, but it may also increase the free (unbound) concentration of olprinone due to reduced protein binding. The aim of this study was to investigate the effect of hemodilution on the protein binding of olprinone. METHODS: Eleven patients scheduled for elective cardiac surgery with CPB were enrolled in our study. Olprinone was continuously infused at a rate of 0.2 µg/kg/min from the time of the first surgical incision until the patient arrived at the recovery unit. Protein binding was evaluated twice, just before the start of CPB and at the beginning of withdrawal from CPB. Olprinone concentration and protein binding were determined with high-performance liquid chromatography and ultrafiltration methods, respectively. Olprinone protein binding was also evaluated in vitro. RESULTS: Olprinone protein binding to albumin was 63 % in vitro, but it did not bind to alpha-1 acid glycoprotein. Olprinone protein binding in patients before CPB was 81.5 ± 4.3 %, whereas protein binding at withdrawal from CPB was 63.3 ± 14.3 %. CONCLUSIONS: Unbound olprinone concentration increased by 20 % during CPB, which suggests that the pharmacological effects of olprinone might be enhanced during and after CPB. Close hemodynamic monitoring is necessary to control the effects of olprinone after CPB, because CPB alters olprinone's pharmacokinetics.

Repetitive evaluation of fibrillation cycle length predicts the efficacy of bepridil for interruption of long-lasting persistent atrial fibrillation.

Although bepridil is effective for conversion of long-lasting persistent atrial fibrillation (AF) to sinus rhythm, it sometimes takes a long time to interrupt AF and there is no feasible index to predict its efficacy.In 60 patients with long-lasting persistent AF, bepridil (100-200 mg/day) was administered and continued for 8 weeks while body surface ECG was recorded every 2 weeks. The fibrillation cycle length (FCL) was evaluated using the spectral analysis of the fibrillation waves in each ECG. AF was interrupted in 32 patients receiving bepridil. The conversion was observed at 2 weeks in 4, at 4 weeks in 7, at 6 weeks in 7, and at 8 weeks in 14 patients. When comparing these responders and nonresponders, clinical background characteristics other than the dosage of bepridil did not show any difference and neither did temporal changes in QT parameters and heart rate. In contrast, the FCL and ΔFCL (prolongation in FCL from baseline) became significantly larger in responders than in nonresponders at later observation points (FCL: 177 ± 17 versus 164 ± 19 ms, P = 0.018, and ΔFCL: 38 ± 16 versus 22 ± 12 ms, P < 0.001, at 4-week point; FCL: 188 ± 17 versus 169 ± 19 ms, P = 0.004, and ΔFCL: 49 ± 18 versus 27 ± 14 ms, P < 0.001, at 6-week point).Repetitive evaluation of FCL using spectral analysis of fibrillation waves can be a feasible index to predict the efficacy of bepridil therapy.

Prophylactic cefdinir for pediatric cases of complicated urinary tract infection.

BACKGROUND: This study evaluated the effect of prophylactic cefdinir (3 mg/kg given once daily) for the prevention of recurrent and complicated urinary tract infections (UTI) in pediatric patients. METHODS: The study included 14 infants who were observed for at least 6 months following the first signs of infection (eight boys, six girls; mean age at admission [± SD]: 6.2 [± 7.4] months). Twelve patients had vesico-ureteric reflux (grade I, two; grade II, three; grade III, six; grade IV, one), and two patients had ureteropelvic junction stenosis. RESULTS: No patients discontinued medication due to diarrhea or other adverse drug reactions. The patients had a 6-month recurrence-free rate of 93% (13/14); only one patient had recurrent UTI. The mean urinary cefdinir concentration was 16.3 [± 11.7]µg/mL; there was considerable variability among individual measurements, even though the samples were collected at similar intervals after drug intake (mean 18.00 [± 2.63] h after dose). However, the lowest measured urinary cefdinir concentration (1.16 µg/mL) was sufficient to eradicate Escherichia coli, one of the most significant causes of UTI. Fecal cultures, obtained at monthly clinic visits during the observation period, indicated that the patients' E. coli strains were very sensitive to cefdinir. No patients were infected with Pseudomonas aeruginosa or other non-fermenting Gram-negative bacilli or fungi. CONCLUSIONS: These results show that cefdinir given 3 mg/kg once daily is very effective and safe for preventing recurrent complicated UTI in infants.

Evaluation of long-term practical training of graduate students at an off-campus hospital-questionnaire survey of graduate students and pharmacists-.

The graduate students in our laboratory underwent 4-5 months of training at Maizuru Kyosai Hospital. To evaluate the effectiveness of this long-term practical training course of the off-campus hospital, we conducted a questionnaire survey before and after the course among the students and the pharmacists. The results of the survey suggest that the students gained experience regarding pharmaceutical management and came to understand the importance of pharmaceutical care during the course. They had an opportunity to connect clinical practice with the research activities conducted at the university. With regard to the pharmacists, this course has motivated them to act as mentors during the practical training, and therefore was also of significance to them. However, this long-term practical training at the off-campus hospital necessitated a change in lifestyle and living arrangements for the students, which placed stress on them. They required emotional support from university staff before and during the placement. These results show that in order to maintain close collaboration with the hospital and to ensure the success of long-term practical training at an off-campus hospital, academic and emotional support for the students is necessary.

Pharmacokinetics of ceftriaxione, a third-generation cephalosporin, in pediatric patients.

We monitored the serum concentration of ceftriaxone (CTRX) in order to clarify its pharmacokinetics in pediatric patients. Subjects were 21 patients undergoing CTRX therapy (50 mg/kg/d) for pneumonia from January to September 2007. To determine the serum concentration of CTRX and to obtain other laboratory data, blood samples were drawn just before and after drug administration. To clarify the relationship between protein concentration and the protein binding ratio of CTRX in vitro and in vivo, the effect of human albumin on the binding ratio was investigated. Thereafter, the relationship between the protein binding ratio and the concentration of CTRX in pediatric patients was analyzed. There was no significant correlation between age and the elimination half-life of CTRX. Moreover, no significant differences were observed in the distribution volume and the clearance between pediatric patients and adults. The binding ratios increased with increased CTRX and albumin concentrations in both in vitro and in vivo studies. It was suggested that the CTRX concentration just before administration (i.e., C(trough)) was sufficiently maintained above the mean inhibitory concentration against Streptococcus pneumoniae and Haemophilus influenzae. Therefore, CTRX administration once daily to pediatric patients with pneumonia was shown to be bacteriologically and pharmacokinetically superior in terms of efficacy.

Relationship between serum aprindine concentration and neurologic side effects in Japanese.

The aim of this study was to evaluate the relationship between the neurologic side effects associated with serum aprindine concentrations and the safety range of aprindine for the prevention of neurologic side effects in 142 Japanese inpatients. Serum aprindine concentrations were determined by high-performance liquid chromatography. A poor positive correlation was observed between dose and serum aprindine concentration (r(2)=0.0419, p=0.0114), and between age and ratio of serum aprindine concentration to the dose per body weight of aprindine (r(2)=0.0159, p=0.121). When aprindine concentration was <1 microg/ml, almost no patients showed neurologic side effects associated with aprindine. On the other hand, about 50% of the patients showed neurologic side effects when aprindine concentrations were >1 microg/ml. Here, the side effects associated with aprindine such as dizziness or intention tremors were observed in 15 patients, which later disappeared after discontinuance of aprindine therapy or a decrease in the dose. In conclusion, serum aprindine concentration should be maintained under approximately 1 microg/ml in Japanese patients to prevent neurologic side effects.

Effects of serum concentrations of disopyramide and its metabolite mono-N-dealkyldisopyramide on the anticholinergic side effects associated with disopyramide.

The aim of this study was to evaluate the relationship between the anticholinergic side effects associated with disopyramide (DP) and serum DP or mono-N-dealkyldisopyramide (MND) concentrations and the safety range of DP or MND for prevention of anticholinergic side effects in 141 inpatients. The serum DP and MND concentrations were determined by high-performance liquid chromatography. No correlation was observed between creatinine clearance (Ccr) and the ratio of the serum concentration to the dose (C/D) of DP, but a significant inverse correlation was observed between Ccr and the C/D of MND. It was observed that the ratio of MND concentration to DP concentration in the group, whose Ccr was below 20 ml/min, was higher than that of the other groups. Although no significant difference was observed in the DP concentration between the patients without (Group 1) or with (Group 2) anticholinergic side effects, significant differences were observed in the MND concentration, Ccr, and the ratio of MND/DP. The DP concentrations of both Groups 1 and 2 were distributed from 0.13 to about 5 microg/ml. On the other hand, although the MND concentrations of Group 1 were below about 1 microg/ml, the MND concentrations of Group 2 were above about 1 microg/ml. These results suggest that not only DP concentration but also MND concentration should be monitored in patients whose renal function is decreased to prevent anticholinergic side effects associated with DP, and that when serum MND concentration was over approximately 1 microg/ml, the dose should be decreased or discontinued.

The effect of bucolome, a CYP2C9 inhibitor, on the pharmacokinetics of losartan.

Losartan, a selective angiotensin receptor antagonist, is mainly metabolized by CYP2C9 to an active carboxylic acid, E3174, which is pharmacologically more potent inhibitor than the parent compound. We evaluated the effect of bucolome, a CYP2C9 inhibitor, on the pharmacokinetics of losartan and E3174, which were measured by high performance liquid chromatography in human volunteers and rats. A randomized crossover design study with two phases was done in the volunteer study. In the first phase, the volunteers received losartan 25 mg alone orally (LOS group), and, in the second phase, losartan 25 mg was given after repeated oral administration of 300 mg bucolome for 7 days (LOS+BUC group). In the LOS group, the maximum concentration (C(max)) and area under the concentration curve (AUC) of losartan were significantly higher than in the LOS+BUC group. On the other hand, in the LOS+BUC group, the C(max) and AUC of E3174 were significantly lower than in the LOS group. In the rat study, male Wistar ST rats were used. In the first phase, the rats orally received losartan 10 mg/kg alone or after bucolome was given repeatedly at a dose of 20, 50, or 200 mg/kg for 7 days. In the second phase for steady state, the rats were given losartan 10 mg/kg for 14 days (group A) or losartan 10 mg/kg and bucolome 50 mg/kg for 14 days (Group B). Bucolome at doses 50 and 200 mg/kg significantly increased the AUC losartan and significantly decreased the AUC of 3174. At the steady state, there were no significant differences in AUC of losartan between Group A and B, but the C(max) and AUC of E3174 were significantly lower in Group B than Group A.

Effect of congestive heart failure on mexiletine pharmacokinetics in a Japanese population.

OBJECTIVE: The goal of this study was to evaluate the influence of congestive heart failure (CHF) on the clearance of mexiletine. METHODS: The mexiletine clearance/bioavailability (CL/F) ratio was estimated in 584 inpatients receiving mexiletine therapy. The study population consisted of 210 patients with CHF [CHF group; 116 inpatients with New York Heart Association (NYHA) class I-II (group NYHA I-II) CHF and 94 inpatients with NYHA class III-IV (group NYHA III-IV) CHF] and 374 inpatients without CHF (Non-CHF group). Serum levels of mexiletine were determined by high performance liquid chromatography (HPLC). RESULTS: Mexiletine clearance was significantly lower in the CHF group when compared with the Non-CHF group (0.264+/-0.093 vs. 0.393+/-0.082 l/h/kg, mean+/-S.D., p<0.05). Further, the CL/F ratio was 50% lower in group NYHA III-IV when compared with the Non-CHF group, and the CL/F ratio tended to change in inverse proportion to NYHA class. CONCLUSION: CHF status significantly affects mexiletine clearance. Therefore, dose adjustments and careful monitoring are likely required in CHF patients receiving mexiletine.

Effect of amiodarone on the serum concentration/dose ratio of metoprolol in patients with cardiac arrhythmia.

Amiodarone has pharmacokinetic interactions with a number of therapeutic drugs, including warfarin, phenytoin, flecainide, and cyclosporine. Metoprolol is mainly metabolized by CYP2D6, and desethylamiodarone, a metabolite of amiodarone, has a markedly greater inhibitory effect on CYP2D6 than amiodarone. Therefore, the goal of this study was to evaluate the effect of amiodarone and desethylamiodarone on the serum concentration/dose ratio (C/D) of metoprolol in 120 inpatients with cardiac arrhythmias that received either metoprolol and amiodarone (MET+AMD group, n=30) or metoprolol alone (MET group, n=90). The ratio of administered metoprolol was compared between the MET and the MET+AMD groups. The dose of metoprolol and patient age were significantly higher in the MET group when compared with the MET+AMD group (1.00+/-0.480 versus 0.767+/-0.418 mg/kg/day, p<0.050; 68.6+/-10.6 versus 57.6+/-14.1 years, p<0.001, respectively), but the C/D ratio was significantly lower in the MET group than in the MET+AMD group (90.8+/-64.0 versus 136+/-97.8, p<0.01). Furthermore, a significant correlation was found between the C/D ratio and desethylamiodarone concentration (n=30, r=0.371, p<0.01). The results suggest that there is a significant interaction between amiodarone and metoprolol via desethylamiodarone-induced inhibition of CYP2D6. Therefore, careful monitoring of metoprolol concentrations/bioactivity of CYP2D6 is required in the context of co-administration of amiodarone and metoprolol.

Pharmacokinetic characteristics of amiodarone in long-term oral therapy in Japanese population.

To evaluate the pharmacokinetic properties and an optimum dose schedule of amiodarone in long-term oral therapy, serum concentrations of amiodarone and its metabolite, desethylamiodarone, were monitored from 345 Japanese inpatients who received amiodarone therapy for a variety of cardiac arrhythmias. Serum amiodarone and desethylamiodarone concentrations were determined by high performance liquid chromatography system. It was observed that the amiodarone and desethylamiodarone concentrations gradually increased with time. The frequency distribution in the amiodarone clearance of 245 subjects, who received fixed maintenance amiodarone therapy for at least 6 months, was nearly a unimodal one. The variation in the ratio of desetylamiodarone to amiodarone concentration in serum was very small. Although no differences in age, dose, dose duration, amiodarone or desethyamiodarone concentration or ratio were observed between men and women: however, the mean amiodarone clearance of women was significantly higer than that of men. The laboratory data were mostly within normal values and no significant relations were observed between serum amiodarone concentration and clinical laboratory data. These results suggest that the individual variation in pharmacokinetics of amiodarone is comparatively small, which might be sufficient to decide that the maintenance dose was the same one (200 mg/d) in long-term oral amiodarone therapy.

Effect of protein binding of pilsicainide on the pharmacokinetics.

To evaluate the effect of protein binding of pilsicainide on its clearance and the contribution of protein binding to optimized pilsicainide therapy, clinical laboratory and pharmacokinetic data were studied in 160 Japanese inpatients (Study 1) and 18 Japanese inpatients (Study 2). To determine the relation between protein concentration and the protein binding ratio of pilsicainide in vitro, the effect of human alpha1-acid glycoprotein (AAG) and human albumin on the binding ratio was studied. The mean ratio of serum pilsicainide concentration to dose per body weight (C/D) increased with increases in the C-reactive protein (CRP) concentration in Study 1. The AAG level increased with increases in the CRP concentration and the binding ratio increases in the AAG concentration in the Study 2. The binding ratios increased with increased AAG and albumin concentrations; the AAG concentration relative to the ratio was particularly large in vitro study. These results suggest C/D is increased in patients with high CRP levels because of binding of pilsicainide to protein, resulting decreased clearance.

Stereoselective effect of amiodarone on the pharmacokinetics of racemic carvedilol.

We investigated whether there was a stereoselective effect of amiodarone on the pharmacokinetics of carvedilol. Among a series of 106 inpatients with heart failure, 52 received carvedilol monotherapy (carvedilol group) and 54 received carvedilol plus amiodarone (carvedilol+amiodarone group). The serum carvedilol concentration administered/dose ratio was compared between the two groups based on HPLC measurement of the serum levels of carvedilol, amiodarone, and desethylamiodarone. In 6 patients from the carvedilol group, serum carvedilol levels were compared before and after coadministration of amiodarone. There was no significant between-group difference of the serum concentration to dose (C/D ratio) for the R-enantiomer carvedilol, however, the C/D ratio for the S-enantiomer and the serum S-carvedilol to R-carvedilol (S/R) ratio were both significantly lower in the carvedilol group than in the carvedilol+amiodarone group(47.8+/-56.7 versus 95.3+/-105 ng/mg/kg, P=0.0048 and 0.460+/-0.207 versus 0.879+/-0.377 ng/mg/kg, P<0.001), respectively. Furthermore, the mean S-carvedilol concentration over 14 days of coadministration with amiodarone was higher than that before coadministration (6.54+/-1.73 ng/mL versus 3.03+/-0.670 ng/mL, P<0.001). These results suggest that metabolism of S-carvedilol was markedly inhibited by coadministration of amiodarone.

Reduction of allergic airway eosinophilia by dietary raffinose in Brown Norway rats.

Oral administration of raffinose, a naturally occurring indigestible oligosaccharide, has reportedly ameliorated atopic dermatitis in human subjects although the mechanism is unknown. The present study investigated the effect of dietary raffinose on allergen-induced airway eosinophilia in ovalbumin-sensitised Brown Norway rats as an atopic disease model. Brown Norway rats were immunised by subcutaneous injection with ovalbumin on day 0 and fed either a control diet or the diet supplemented with raffinose (50 g/kg diet). The rats were exposed to aerosolised ovalbumin on day 20, and broncho-alveolar lavage fluid was obtained on the next day. The number of eosinophils in the fluid was significantly lower in the rats fed the raffinose diet than in those fed the control diet. Dietary raffinose significantly reduced IL-4 and IL-5 mRNA levels in lung tissue and tended to lower ovalbumin-specific Ig E levels. Suppression of eosinophilia by dietary raffinose was still observed in caecectomised and neomycin-administered rats, suggesting little contribution by the colonic bacteria to the effect of raffinose. Intraperitoneal administration of raffinose also suppressed eosinophilia. Significant concentrations of raffinose were detected in portal venous and abdominal arterial plasma after the intragastric administration of raffinose. Overall, the findings suggest that dietary raffinose ameliorates allergic airway eosinophilia at least partly via post-absorptive mechanisms in Brown Norway rats.

Evaluation of factors to decrease bioavailability of cyclosporin A in rats with gentamicin-induced acute renal failure.

Focusing on the disposition of cyclosporin A (CsA) in the liver and intestine, effects of gentamicin-induced acute renal failure (ARF) on the decreased oral bioavailability of CsA were evaluated in rats. The area under the CsA concentration-time curve (AUC) in ARF rats after oral administration (5 mg/kg) significantly decreased by 43% as compared to the control, while the apparent oral clearance significantly increased by 76% of the control. The portal AUC of CsA in ARF rats with bile flow decreased by 67% as compared to the control rats. Without bile flow, the portal AUC of CsA in control rats decreased by 50% as compared to those with bile flow, whereas ARF rats without bile flow showed no notable change as compared to those with bile flow. The AUC of CsA mono-oxidative metabolite via CYP3A (M-OH) in ARF rats after oral or intravenous administration increased significantly by 84% or 241%, respectively, while there was no difference in the portal M-OH between control and ARF rats, suggesting that the elimination of M-OH was prolonged because of nephrotoxicity. Although the exsorption clearance of CsA from the blood circulation to the intestine after intravenous administration to ARF rats decreased significantly as compared to the control; and basolateral-to-apical transport of CsA through Caco-2 monolayers was significantly retarded in the presence of uremic toxins, there was no significant change in the total body clearance of CsA between ARF and control rats. Moreover, there were no effects of uremic toxins on the protein binding of CsA in plasma. These observations suggest that hepatic or intestinal CYP3A and P-glycoproteine (P-gp) are not likely to be concerned with lowering the oral bioavailability of CsA, and that bile function under the ARF condition induced by gentamicin is responsible for a marked decrease in the fraction absorbed of CsA in the small intestine.

Isolation of tryptophan as an inhibitor of ovalbumin permeation and analysis of its suppressive effect on oral sensitization.

Tryptophan was isolated from rat feces as an active compound against ovalbumin permeation in an in vitro Caco-2 cell model. Tryptophan dose-dependently inhibited ovalbumin permeation with accompanying increase in transepithelial electric resistance, and its inhibitory activity reached a plateau at 10 mM. Brown Norway rats were sensitized by intragastric administration of ovalbumin together with or without tryptophan. Antibody levels specific to ovalbumin in the sera and proliferative responses of spleen mononuclear cells to ovalbumin were significantly lower in rats administered ovalbumin plus tryptophan than those administered ovalbumin alone. These results suggest that tryptophan suppresses oral sensitization to ovalbumin, probably via suppression of ovalbumin absorption from the intestinal tract.