Independent Factors Contributing to Daytime and Nighttime Asthmatic Cough Refractory to Inhaled Corticosteroids.

BACKGROUND: Cough is a common feature of asthma, which is often resistant to inhaled corticosteroids (ICSs). The pathophysiology of this refractoriness may differ between daytime and nighttime asthmatic cough. We sought to identify factors contributing to ICS-refractory daytime and nighttime asthmatic cough. METHODS: Sixty-seven patients with asthma presenting solely or predominantly with chronic cough were prospectively enrolled from April 2012 to December 2014. At baseline and 12 weeks after ICS treatment, the capsaicin cough threshold (C2, C5) and methacholine airway sensitivity and reactivity were examined. A visual analog scale (VAS) and numeric scores were used to evaluate daytime and nighttime cough symptoms separately. The Japanese version of the Leicester Cough Questionnaire was also completed. When either the VAS or numeric scores showed an improvement of ≥50% or ≥2 points, patients were considered responders to ICS treatment. RESULTS: Fifty-five patients were eligible for evaluation. Subjective cough indices improved significantly at 12 weeks after ICS treatment (P<.001). Multivariate analysis revealed that lower C2 significantly contributed to residual daytime cough (P=.04). Meanwhile, methacholine hyperreactivity and lower IgE levels were predictors of the nighttime residual cough (P=.002 and P=.03, respectively). CONCLUSIONS: Heightened cough reflex sensitivity is an independent factor of daytime asthmatic cough that is refractory to ICSs. In contrast, airway hyperreactivity and less atopic status contribute to ICS-refractory nighttime cough.

IL4Rα and ADAM33 as genetic markers in asthma exacerbations and type-2 inflammatory endotype.

BACKGROUND: Genetic markers of susceptibility to asthma exacerbations in adults remain unclear. OBJECTIVE: To identify genetic markers of asthma exacerbations, particularly in patients with type-2 inflammatory endotype. METHODS: In this observational study of patients enrolled in the Kinki Hokuriku Airway disease Conference multicenter study, frequency of exacerbations requiring systemic corticosteroids during 2 years after enrolment and associated risk factors was determined. For genetic marker analysis, interleukin-4 receptor α (IL4RA) rs8832 and a disintegrin and metalloprotease 33 (ADAM33) S_2 (rs528557), T_1 (rs2280091), T_2 (rs2280090), and V_4 (rs2787094) variants were included. Elevated serum periostin levels at enrolment (≥95 ng/mL, defined as type-2 inflammatory endotype) were considered in the analysis. RESULTS: Among 217 patients who were successfully followed up for 2 years after enrolment, 60 patients showed at least one asthma exacerbation during the 2 years. Airflow limitation (%FEV1 <80%) and recent exacerbations but not genetic variants were identified as risk markers of exacerbations. A total of 27 patients showed type-2 inflammatory endotype (serum periostin ≥95 ng/mL at enrolment) and subsequent exacerbations; risk factors in these patients were airflow limitation (odds ratio, 6.51; 95% confidence interval (CI): 2.37-18.6; P=.0003), GG genotype of IL4RA rs8832 (odds ratio, 4.01; 95% CI: 1.47-11.0; P=.007), and A allele of ADAM33 T_2 (odds ratio, 2.81; 95% CI: 1.05-7.67; P=.04) by multivariate analysis. In addition, GG genotype of IL4RA rs8832 was associated with type-2 endotype, whereas A allele of ADAM33 T_2 was associated with mixed type of eosinophilic/type-2 and neutrophilic inflammations. CONCLUSIONS AND CLINICAL RELEVANCE: IL4RA and ADAM33 variants may be risk markers of asthma exacerbations in type-2 inflammatory endotype. Precise endotyping may facilitate the identification of genetic risk markers of asthma exacerbations.

Mouth breathing, another risk factor for asthma: the Nagahama Study.

BACKGROUND: Allergic rhinitis, a known risk factor for asthma onset, often accompanies mouth breathing. Mouth breathing may bypass the protective function of the nose and is anecdotally considered to increase asthma morbidity. However, there is no epidemiological evidence that mouth breathing is independently associated with asthma morbidity and sensitization to allergens. In this study, we aimed to clarify the association between mouth breathing and asthma morbidity and allergic/eosinophilic inflammation, while considering the effect of allergic rhinitis. METHODS: This community-based cohort study, the Nagahama Study, contained a self-reporting questionnaire on mouth breathing and medical history, blood tests, and pulmonary function testing. We enrolled 9804 general citizens of Nagahama City in the Shiga Prefecture, Japan. RESULTS: Mouth breathing was reported by 17% of the population and was independently associated with asthma morbidity. The odds ratio for asthma morbidity was 1.85 (95% CI, 1.27-2.62) and 2.20 (95% CI, 1.72-2.80) in subjects with mouth breathing alone and allergic rhinitis alone, which additively increased to 4.09 (95% CI, 3.01-5.52) when mouth breathing and allergic rhinitis coexisted. Mouth breathing in nonasthmatics was a risk for house dust mite sensitization, higher blood eosinophil counts, and lower pulmonary function after adjusting for allergic rhinitis. CONCLUSION: Mouth breathing may increase asthma morbidity, potentially through increased sensitization to inhaled allergens, which highlights the risk of mouth-bypass breathing in the 'one airway, one disease' concept. The risk of mouth breathing should be well recognized in subjects with allergic rhinitis and in the general population.

Utility of serum periostin and free IgE levels in evaluating responsiveness to omalizumab in patients with severe asthma.

BACKGROUND: Omalizumab, a humanized anti-IgE monoclonal antibody, has demonstrated efficacy in patients with severe allergic asthma. However, treatment responses vary widely among individuals. Despite a lack of data, free serum IgE levels following omalizumab treatment have been proposed as a marker of treatment responsiveness. METHODS: In this prospective, observational study, we assessed the utility of biomarkers of type 2 inflammation in predicting omalizumab treatment responses, as determined by the absence of asthma exacerbation during the first year of treatment. Free serum IgE levels were monitored for 2 years to examine their association with baseline biomarker levels and the number of exacerbations. RESULTS: We enrolled thirty patients who had been treated with omalizumab for at least 1 year, of whom 27 were treated for 2 years. Baseline serum periostin levels and blood eosinophil counts were significantly higher in patients without exacerbations during the first year of treatment than in patients with exacerbations. Baseline serum periostin levels, but not eosinophil counts, were negatively associated with free serum IgE levels after 16 or 32 weeks of treatment. Reduced free serum IgE levels during treatment from those at baseline were associated with reduced exacerbation numbers at 2 years. In 14 patients who continued to have exacerbations during the first year of treatment, exacerbation numbers gradually and significantly decreased over the 2-year study period, with concurrent significant reductions in free serum IgE levels. CONCLUSION: Baseline serum periostin levels and serum free IgE levels during treatment follow-up may be useful in evaluating responses to omalizumab treatment.

GLCCI1 variant accelerates pulmonary function decline in patients with asthma receiving inhaled corticosteroids.

BACKGROUND: In steroid-naive patients with asthma, several gene variants are associated with a short-term response to inhaled corticosteroid (ICS) treatment; this has mostly been observed in Caucasians. However, not many studies have been conducted for other ethnicities. Here, we aimed to determine the relationship between the annual decline in forced expiratory flow volume in one second (FEV1 ) and the variant of the glucocorticoid-induced transcript 1 gene (GLCCI1) in Japanese patients with asthma receiving long-term ICS treatment, taking into account the effect of high serum periostin levels, a known association factor of pulmonary function decline and a marker of refractory eosinophilic/Th2 inflammation. METHODS: In this study, 224 patients with asthma receiving ICS treatment for at least 4 years were enrolled. The effects of single-nucleotide polymorphisms (SNPs) in GLCCI1, stress-induced phosphoprotein 1 (STIP1), and T gene on the decline in FEV1 of 30 ml/year or greater were determined. RESULTS: Besides the known contributing factors, that is, the most intensive treatment step, ex-smoking, and high serum periostin levels (≥95 ng/ml), the GG genotype of GLCCI1 rs37973, and not other SNPs, was independently associated with a decline in FEV1 of 30 ml/year or greater. When patients were stratified according to their serum periostin levels, the GG genotype of rs37973 was significantly associated with blood eosinophilia (≥250/µl) in the high serum periostin group. CONCLUSIONS: A GLCCI1 variant is a risk factor of pulmonary function decline in Japanese patients with asthma receiving long-term ICS treatment. Thus, GLCCI1 may be associated with response to ICS across ethnicities.

Smoking attenuates the age-related decrease in IgE levels and maintains eosinophilic inflammation.

BACKGROUND: Epidemiological studies have shown that smoking increases the propensity for atopy and asthma. However, the effects of smoking on atopy and eosinophilic inflammation in asthmatics, including the elderly, remain unknown. OBJECTIVE: To determine the effects of smoking on serum immunoglobulin E (IgE) levels and eosinophilic inflammation in asthmatics of all ages. METHODS: The associations of serum IgE levels, blood eosinophil counts and fractional exhaled nitric oxide (FeNO) levels with smoking and age in steroid-naive asthmatics were cross-sectionally assessed (n = 307). Levels of sputum eosinophil and thymic stromal lymphopoietin (TSLP) that promotes Th2 inflammation were also analysed. Current smokers were excluded when analysing contributing factors of FeNO. RESULTS: Levels of serum IgE, blood eosinophil and FeNO decreased with increasing age in never-smokers, whereas decrease in serum IgE levels with increasing age was not observed in current smokers. In addition, current smoking was associated with higher blood eosinophil counts. In atopic asthmatics, age-related declines in serum IgE levels were less steep in ex-smokers than in never-smokers, and atopic ex-smokers with asthma showed higher blood eosinophil counts and higher FeNO irrespective of age. Lastly, sputum TSLP levels were associated with sputum eosinophil proportions and pack-years. Current and ex-smokers had higher TSLP levels than never-smokers. CONCLUSIONS AND CLINICAL RELEVANCE: In steroid-naive asthmatics, smoking may attenuate the age-related decrease in IgE levels and maintain eosinophilic inflammation, in which TSLP may be involved.

Long-term changes in airway-wall thickness on computed tomography in asthmatic patients.

BACKGROUND: Effects of long-term treatment with inhaled corticosteroids (ICSs) on airway-wall thickness in patients with asthma remain unknown. OBJECTIVES: To determine whether airway-wall thickness consistently decreases after long-term ICS treatment, and to analyze factors contributing to long-term airway-wall changes in asthmatics. METHODS: A retrospective analysis of long-term changes in airway-wall thickness using computed tomography was performed in 14 patients with asthma. Wall area corrected by body surface area (WA/BSA) was examined at baseline, 12 weeks after the commencement of ICSs (second measurement), and at least 2 years (mean +/- SEM. 4.2 +/- 0.5) after the second measurement (third measurement). Mean +/- SEM changes in WA/BSA from the second to the third measurements were analyzed. RESULTS: The mean change in WA/BSA was not significant between the second and the third measurements (-0.27 +/- 0.59 mm2/m2/y). Overall, the changes were significantly associated with disease duration but not with other clinical indices. When the 14 patients were divided into 2 groups using a cutoff value of 0.32 mm2/m2/y for the mean change in WA/BSA, for the 5 patients whose WA/BSA exceeded this cutoff, daily ICS doses were not reduced and both forced expiratory volume in the first second (FEV1) and forced vital capacity decreased significantly. For the remaining 9 patients, daily ICS doses were reduced and long-term FEV1 values did not change. CONCLUSIONS: Despite long-term treatment with ICSs, airway-wall thickness did not consistently decrease. One possible mechanism underlying poor response to long-term treatment may be long-standing asthma.

Evidence that errors made by DNA polymerase alpha are corrected by DNA polymerase delta.

Eukaryotic replication begins at origins and on the lagging strand with RNA-primed DNA synthesis of a few nucleotides by polymerase alpha, which lacks proofreading activity. A polymerase switch then allows chain elongation by proofreading-proficient pol delta and pol epsilon. Pol delta and pol epsilon are essential, but their roles in replication are not yet completely defined . Here, we investigate their roles by using yeast pol alpha with a Leu868Met substitution . L868M pol alpha copies DNA in vitro with normal activity and processivity but with reduced fidelity. In vivo, the pol1-L868M allele confers a mutator phenotype. This mutator phenotype is strongly increased upon inactivation of the 3' exonuclease of pol delta but not that of pol epsilon. Several nonexclusive explanations are considered, including the hypothesis that the 3' exonuclease of pol delta proofreads errors generated by pol alpha during initiation of Okazaki fragments. Given that eukaryotes encode specialized, proofreading-deficient polymerases with even lower fidelity than pol alpha, such intermolecular proofreading could be relevant to several DNA transactions that control genome stability.

Body mass index in male patients with COPD: correlation with low attenuation areas on CT.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is characterised by the presence of airflow limitation caused by loss of lung elasticity and/or airway narrowing. The pathological hallmark of loss of lung elasticity is emphysema, and airway wall remodelling contributes to the airway narrowing. Using CT, these lesions can be assessed by measuring low attenuation areas (LAA) and airway wall thickness/luminal area, respectively. As previously reported, COPD can be divided into airway dominant, emphysema dominant and mixed phenotypes using CT. In this study, it is postulated that a patient's physique may be associated with the relative contribution of these lesions to airflow obstruction. METHODS: CT was used to evaluate emphysema and airway dimensions in 201 patients with COPD. Emphysema was evaluated using percentage of LAA voxels (LAA%) and airway lesion was estimated by percentage wall area (WA%). Patients were divided into four phenotypes using LAA% and WA%. RESULTS: Body mass index (BMI) was significantly lower in the higher LAA% phenotype (ie, emphysema dominant and mixed phenotypes). BMI correlated with LAA% (rho = -0.557, p<0.0001) but not with WA%. BMI was significantly lower in the emphysema dominant phenotype than in the airway dominant phenotype, while there was no difference in forced expiratory volume in 1 s %predicted between the two. CONCLUSION: A low BMI is associated with the presence of emphysema, but not with airway wall thickening, in male smokers who have COPD. These results support the concept of different COPD phenotypes and suggest that there may be different systemic manifestations of these phenotypes.

Impact of gastro-oesophageal reflux disease symptoms on COPD exacerbation.

BACKGROUND: The association between gastro-oesophageal reflux disease (GORD) and chronic obstructive pulmonary disease (COPD) exacerbation has so far remained unclear. OBJECTIVE: To prospectively establish the clinical significance of GORD symptoms on exacerbation. METHODS: 82 patients with COPD and 40 age matched controls were enrolled in this study. Symptoms were evaluated by a questionnaire using the Frequency Scale for the Symptoms of GORD (FSSG). Patients with COPD were prospectively surveyed for 6 months, and episodes of exacerbation were identified using a diary based on modified Anthonisen's criteria. Exhaled breath condensate (EBC) pH was measured in both groups, and induced sputum was evaluated in patients with COPD. RESULTS: Positive GORD symptoms were reported in 22 (26.8%) patients with COPD and in five (12.5%) controls (p = 0.10). The frequency of exacerbations was significantly associated with the FSSG score (p = 0.03, r = 0.24, 95% CI 0.02 to 0.43). Multiple regression analysis revealed that GORD symptoms were significantly associated with the occurrence of exacerbations (p<0.01; relative risk 6.55, 95% CI 1.86 to 23.11). EBC pH was inversely correlated with FSSG score in both groups (p = 0.01, r = -0.37, 95% CI -0.55 to -0.14 in patients with COPD, and p<0.01, r = -0.45, 95% CI -0.67 to -0.16 in control subjects). CONCLUSIONS: GORD symptoms were identified as an important factor associated with COPD exacerbation.

Sputum levels of transforming growth factor-beta1 in asthma: relation to clinical and computed tomography findings.

BACKGROUND: Transforming growth factor (TGF) beta1 is considered to play central roles in the pathogenesis of airway remodeling in asthma. This notion is based primarily on the results of experimental studies; clinical evidence is limited. OBJECTIVES: To ascertain the involvement of TGF-beta1 in asthma. METHODS: We studied 27 patients with moderate-to-severe, but stable, asthma treated with inhaled corticosteroids and 8 healthy controls. Helical computed tomography scans were acquired at full inspiration. Airway wall thickness (WT) was assessed on the basis of wall area corrected for body surface area (WA/BSA) and absolute WT corrected for BSA (WT/square root of BSA) according to a validated method. Induced sputum concentrations of TGF-beta1 were measured by enzyme-linked immunosorbent assay. Pulmonary function was evaluated. RESULTS: Indices of expiratory airflow were significantly lower in the asthmatic patients than in the controls. WA/BSA, WT/square root of square root of BSA, and sputum concentrations of TGF-beta1 were significantly higher in the asthmatic patients. Sputum TGF-beta1 concentrations correlated positively with WA/BSA and WT/square root of BSA and negatively with forced expiratory volume in 1 second in both asthmatic and control subjects. CONCLUSIONS: Levels of TGF-beta1 in induced sputum are elevated in asthmatic patients despite treatment with inhaled corticosteroids and are associated with airflow obstruction and airway wall thickening. TGF-beta1 is involved in the pathogenesis of airway remodeling and resultant functional impairment and it may be a target for specific medical treatment.

Atopic features of cough variant asthma and classic asthma with wheezing.

BACKGROUND: Cough variant asthma is a phenotype of asthma solely presenting with coughing. It involves airway inflammation and remodelling as does classic asthma with wheezing, and a subset of patients may progress to classic asthma. The atopic features of cough variant asthma remain unclear. OBJECTIVE: To compare atopic features between patients with cough variant asthma and those with classic asthma, and to examine the possible correlation of these features with the future development of wheezing in the former group. METHODS: Total and specific IgE levels of seven common aeroallergens [house dust mite (HDM), Gramineae/Japanese cedar/weed pollens, moulds, cat/dog dander] were examined in 74 cough variant asthma patients and in 115 classic asthma patients of varying severity. Forty of the former patients were prospectively observed for 2 years to determine whether cough variant asthma progressed to classic asthma despite inhaled corticosteroid treatment. RESULTS: Patients with classic asthma had higher total IgE (P<0.0001), larger numbers of sensitized allergens (P=0.03), and higher rates of sensitization to dog dander (24% vs. 3%, P<0.0001), HDM (46% vs. 28%, P=0.02), and moulds (17% vs. 7%, P=0.047) than did patients with cough variant asthma. Wheezing developed in six (15%) patients with cough variant asthma, who were sensitized to larger numbers of allergens (P=0.02) and had higher rates of sensitization to HDM (P=0.01) and dog dander (P=0.02) than the 34 patients in whom wheezing did not develop. Among the patients with classic asthma, total and specific IgE variables were similar in the subgroup with mild disease (n=60) and the subgroup with moderate-to-severe disease (n=55), as reported previously. CONCLUSIONS: Atopy may be related to the development of wheezing in patients with cough variant asthma. To prevent the progression of cough variant asthma to classic asthma, avoidance of relevant allergens may be essential.

Effect of nCPAP therapy on heart rate in patients with obstructive sleep apnoea-hypopnoea.

BACKGROUND: Elevated heart rate (HR) is a risk factor for cardiovascular disease. The effects of obstructive sleep apnoea-hypopnoea syndrome (OSAHS) on HR are controversial. AIM: To investigate the effect of nasal continuous positive airway pressure (nCPAP) therapy on HR in OSAHS patients. METHODS: Sixty-two OSAHS patients underwent 24-h electrocardiographic recording, both before and 3 or 4 days after instigation of nCPAP. RESULTS: After nCPAP was started, HR significantly decreased (mean +/- SD 71.8 +/- 10.6 vs. 67.5 +/- 9.4 bpm, p < 0.0001), both in the daytime (0600-2200 h, 76.3 +/- 12.2 vs. 72.2 +/- 10.2 bpm, p < 0.0001) and at night-time (2200-0600 h, 64.5 +/- 9.1 vs. 60.0 +/- 8.9 bpm, p < 0.0001). HR was significantly reduced in both periods in the 44 patients with hypertension and/or diabetes mellitus, but only during the night-time in the 18 with neither condition. Before nCPAP treatment, HR was positively correlated with percentage time of arterial O2 saturation <90% during sleep (p = 0.008) and with the apnoea-hypopnoea index during sleep (p = 0.003). In 15 patients undergoing HR for 2 days before starting nCPAP, the mean HRs for the two periods were similar (p = 0.95). DISCUSSION: nCPAP therapy appears to decrease HR in OSAHS patients, and may thereby reduce their risk of cardiovascular disease.

Effects of inhaled corticosteroid and short courses of oral corticosteroids on bone mineral density in asthmatic patients : a 4-year longitudinal study.

BACKGROUND: It is not certain whether inhaled corticosteroid (ICS) therapy reduces bone mineral density (BMD) in asthmatic patients. In addition, the potential risk of osteoporosis associated with the rescue use of short courses of oral corticosteroids (SC-OCS) is unclear. OBJECTIVE: To evaluate the effect of inhaled beclomethasone dipropionate (BDP) and SC-OCS on BMD in asthmatic patients. DESIGN: A 4-year longitudinal study. METHOD: Lumbar BMD was measured twice by dual-energy x-ray absorptiometry at a mean (+/- SD) interval of 4.2 +/- 0.1 years in 35 asthmatic adults (15 men and 20 postmenopausal women; mean age at the second evaluation, 60.6 +/- 11.5 years) who had been treated with BDP and SC-OCS. RESULTS: The average period of BDP treatment was 7.7 +/- 2.2 years (range, 4.8 to 13.0 years) at the second evaluation. During the study period, the daily dose of BDP was 765 +/- 389 microg (range, 100 to 1,730 microg), and the frequency of SC-OCS was 1.9 +/- 2.7 courses per year (range, 0.0 to 8.9 courses per year). As a whole, lumbar BMD was unchanged during the course of the study, whereas the Z score (ie, the percentage of normal value predicted from age and sex) increased significantly. Changes in BMD and Z scores in patients receiving high doses of BDP (ie, > 1,000 microg/d; n = 9) were not significantly different from those of patients receiving lower doses (ie, 2.5 courses per year; n = 9) showed a significantly greater loss in BMD and Z score compared with those receiving sporadic courses (ie,

Effect of proton pump inhibitor alone or in combination with clarithromycin on mycobacterial growth in human alveolar macrophages.

The effect of omeprazole, a clinically used proton pump inhibitor, alone or in combination with clarithromycin was evaluated against Mycobacterium avium, Mycobacterium intracellulare and Mycobacterium tuberculosis, using a human alveolar macrophage model of infection. Omeprazole exhibited no significant effect on the growth of the two M. avium complex strains or on the mycobactericidal activity of clarithromycin against them. In contrast, omeprazole significantly promoted the growth of Mycobacterium tuberculosis and the anti-mycobacterial activity of clarithromycin against it in human alveolar macrophages. It was speculated that intracellular acidic milieu around M. tuberculosis might be one reason for the lower activity of clarithromycin in the treatment of human tuberculosis.

Inhibitory effect of ursodeoxycholic acid on the progression of chronic hepatic disorders with special reference to increases in blood flow.

Ursodeoxycholic acid (UDCA), which is commonly used as a cholesterol-gallstone-dissolving agent, is now expected to be effective not only for primary biliary cirrhosis but for chronic active hepatitis as well. In this study, we administered 0.1% ethionine-added, choline-deficient diet for 8 weeks to male Sprague-Dawley rats to prepare an animal model of chronic hepatic disorders. At the same time, UDCA (50 mg/kg/day) was administered orally to these animals, and its effects on the liver, including effects on hepatic blood flow determined with a laser Doppler blood flow meter, were evaluated. Hepatic blood flow increased significantly in the UDCA group compared with the untreated groups. Transaminase levels decreased significantly in the UDCA group compared with the untreated group. Histologic differences were noted between the UDCA and untreated groups in histopathologic examinations of the liver, with liver cirrhosis or early liver cirrhosis being present in the untreated group, compared with only chronic active hepatitis in the UDCA group. These findings suggest that UDCA is able to prevent or inhibit the progression of chronic hepatic disorders, an effect that may be due in part to increases in hepatic blood flow.

Experimental use of pravastatin in patients with primary biliary cirrhosis associated with hypercholesterolemia.

Primary biliary cirrhosis (PBC) is a refractory liver disease for which no medical treatment has been established. The investigators administered 20 mg/day of pravastatin, a 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitor, to 2 PBC patients with hypercholesterolemia (1010 and 306 mg/dl) for 3 years and 10 months in order to decrease the blood concentration of bile acids and prevent adverse effects on the hepatocellular membrane. The drug markedly decreased not only cholesterol levels but also total bile acid levels, producing particularly pronounced decreases in cholic acid and chenodeoxycholic acid. Histologically, progression was inhibited in one patient, whereas improvement was seen in the other. Bile duct enzymes and other biochemical parameters showed improvement in both cases. General pruritus and blepharal and palmar xanthoma also improved. These findings suggest that pravastatin may be useful in the treatment of PBC associated with hypercholesterolemia.

Role of eicosapentaenoic acid in lipid metabolism in the liver, with special reference to experimental fatty liver.

Choline-deficient feed was given to three groups (n = 7 in each) of male Sprague-Dawley rats for 4 weeks to induce the development of fatty liver. In addition, two of the groups received eicosapentaenoic acid (EPA), 1000 mg/kg/d, administered orally either for all 4 weeks or for only the last 2 weeks of the study, respectively. The third group received the choline-deficient diet but no EPA. The untreated control group (n = 7) received only normal feed. The efficacy of EPA in preventing fatty liver was assessed based on the evaluation of pathologic and biochemical parameters and hepatic blood flow. EPA markedly improved fatty liver, probably due to both direct effects (inhibition of the synthesis of triglyceride in the liver) and indirect effects (increased hepatic blood flow). Decreased blood flow due to sinusoidal block is responsible for the progression of fatty liver. EPA has been shown to decrease thromboxane A2 production and blood viscosity and to enhance red cell deformability. These effects are thought to have contributed to the increases in hepatic blood flow.

Relationship between endothelin and thromboxane A2 in rat liver microcirculation.

In our previous study, we determined changes in hepatic blood flow using a Laser Doppler blood flow meter after i.v. injection of endothelin-1 (ET-1) or endothelin-3 (ET-3) at 2 nmol/kg in rats and found that ET-3 caused greater decreases in blood flow than ET-1. In the present study, we determined how the arachidonic acid cascade, mainly thromboxane A2 (TXA2), is related to ET-1 and ET-3 using indomethacin (INDO), which inhibits the biosynthesis of prostaglandin (PG), and OKY-046, a selective inhibitor of TXA2 synthesis. In the first series of experiments, ET-1 and ET-3 were administered after inhibiting the biosynthesis of PG by s.c. injection of 2 mg/kg of INDO. While INDO failed to inhibit the slight decrease in hepatic blood flow induced by ET-1, it significantly inhibited the marked decrease in hepatic blood flow elicited by ET-3. In the next series of experiments, ET-1 and ET-3 were administered after administration of 20 mg/kg of OKY-046. OKY-046 showed no effects in animals treated with ET-1, as in those pre-treated with INDO, while it significantly inhibited the decreases in hepatic blood flow induced by ET-3. These findings suggest that ET-1 decreases hepatic blood flow due to its direct effects although to a lesser extent than ET-3, while ET-3 does so due not only to its direct effects but also to TXA2-mediated effects. It is therefore likely that in addition to ET family peptides, PG-mediated mechanisms are involved in the regulation of hepatic microcirculation by ETs.