Knocking out a specific tRNA species within unfractionated Escherichia coli tRNA by using antisense (complementary) oligodeoxyribonucleotides

Methods for the preparation of an Escherichia coli tRNA mixture lacking one or a few specific tRNA species can be the basis for future applications of cell-free protein synthesis. We demonstrate here that virtually a single tRNA species in a crude E. coli tRNA mixture can be knocked out by an antisense (complementary) oligodeoxyribonucleotide. One out of five oligomers complementary to tRNA(Asp) blocked the aspartylation almost completely, while minimally affecting the aminoacylation with other 13 amino acids tested. This 'knockout' tRNA behaved similarly to the untreated tRNA in a cell-free translation of an mRNA lacking Asp codons.

In vitro construction of pseudovirions of human papillomavirus type 16: incorporation of plasmid DNA into reassembled L1/L2 capsids

Lack of permissive and productive cell cultures for the human papillomaviruses (HPVs) has hindered the study of virus-neutralizing antibodies and infection. We developed a cell-free system generating infectious HPV16 pseudovirions. HPV16 L1/L2 capsids, which had been self-assembled in insect cells (Sf9) expressing virion proteins L1 and L2, were disassembled with 2-mercaptoethanol (2-ME), a reducing agent, and reassembled by removal of 2-ME in the presence of a beta-galactosidase expression plasmid. Plasmid DNA purified together with the reassembled capsids was resistant to DNase I digestion. The reassembled pseudovirions mediated DNA transfer to COS-1 cells, as monitored by induced beta-galactosidase activity. Transfer was inhibited by anti-HPV16 L1 antiserum but not by antisera against L1s of HPV6 and HPV18. Construction in vitro of HPV pseudovirions containing marker plasmids would be potentially useful in developing methods to assay virus-neutralizing antibodies and to transfer exogenous genes to HPV-susceptible cells.

Effect of troglitazone on microalbuminuria in patients with incipient diabetic nephropathy

OBJECTIVE

Although some studies have suggested a direct action of troglitazone on vascular cells, its effects on diabetic vascular diseases have not been reported. We therefore investigated the effect of troglitazone on microalbuminuria in patients with incipient diabetic nephropathy.

RESEARCH DESIGN AND METHODS

A total of 30 patients with type 2 diabetes associated with microalbuminuria (urinary albumin-to-creatinine ratio [ACR] [milligrams per gram creatinine] ranging from 30 to 300 mg/g creatinine) were studied. They were randomly divided into two groups: patients treated with metformin (500 mg/day, n = 13) or with troglitazone (400 mg/day, n = 17) for 12 weeks. ACR, lipid profile, blood pressure, glycated hemoglobin, and plasma glucose during meal-load tests were measured every 4 weeks.

RESULTS

Anthropometric indices (BMI and percent fat), lipid profile, and blood pressure did not change with either treatment. Fasting and postmeal glucose levels decreased similarly in the two groups. Decrements in glycated hemoglobin were greater in the metformin group at 4 and 8 weeks after the initiation of treatment (P < 0.05). Troglitazone reduced ACR (median [25-75th percentiles]) from 70 (49-195) to 40 (31-90) mg/g creatinine at 4 weeks (P = 0.021) and maintained these reduced levels throughout the treatment period (8 weeks: 35 [26-68], P = 0.007; 12 weeks: 43 [26-103], P = 0.047). Metformin did not change ACR throughout the 12 weeks.

CONCLUSIONS

Troglitazone ameliorated microalbuminuria in diabetic nephropathy. Furthermore, our findings suggest that troglitazone has some effects on vascular cells other than lowering plasma glucose levels. Troglitazone might be useful for diabetic angiopathy, including nephropathy and coronary artery disease.

Quantitative analysis of GBV-C RNA in liver and serum by strand-specific reverse transcription-polymerase chain reaction

BACKGROUND/AIMS

Although GB virus C (GBV-C) is frequently detectable in patients with liver diseases, it is not known whether it actually replicates in the liver. Therefore we have quantitatively examined the strand-specific RNA of this virus.

METHODS

Fourteen patients (two GBV-C RNA only seropositive, seven both GBV-C RNA and HCV RNA seropositive, and five HCV RNA only seropositive) were examined. Extracted RNAs from sera and liver specimens of these patients were serially diluted and strand-specific RNAs of GBV-C and HCV were quantitatively measured using strand-specific primers by reverse transcription-polymerase chain reaction.

RESULTS

Positive-strand GBV-C RNA in serum was detected in all nine GBV-C RNA seropositive cases, and negative-strand RNA was detected in three, uncertain in three, and undetected in three. Positive-strand GBV-C RNA in the liver was detected in seven and undetected in two, while negative-strand RNA in the liver was undetected in eight and uncertain in one. On the other hand, positive-strand HCV RNA was detected in serum from all 12 HCV RNA seropositive patients and negative-strand HCV RNA was detected in one, uncertain in seven, and undetected in four. Positive-strand HCV RNA was detected in the liver from all 12 HCV RNA seropositive patients, and the presence of negative-strand HCV RNA in the liver was confirmed in 10 and uncertain in the remaining two.

CONCLUSION

GBV-C is considered to be far less hepatotropic than HCV, and it is suggested that GBV-C might not be replicating in the liver.

Streptococcus pyogenes hospital-acquired infection within a dermatological ward

Seventeen strains of Streptococcus pyogenes were isolated from 17 patients in the Dermatological Ward of Gunma University Hospital in Japan between June 1994 and March 1995. Of these 17 strains, 14 were isolated from the pus of skin infections, two from blood, and one from ascitic fluid. The strains showed the same minimum inhibitory concentrations; 4 mg/L of minomycin, 4 mg/L of ofloxacin and 16 mg/L of fosfomycin. T-antigen typing of the strains indicated they were T11 type. The restriction endonuclease digestion patterns of chromosomal DNA from the 17 strains were all identical. The vinyl sheet covering the bed on which the patients were treated was found to be contaminated with S. pyogenes. This strain showed identical characteristics to the strains derived from the patients. These results suggest that S. pyogenes was transmitted to patients in the Dermatological Ward from the surface of the vinyl sheet covering the bed.

Endothelin converting enzyme inhibitor protects development of right ventricular overload and medial thickening of pulmonary arteries in rats with monocrotaline-induced pulmonary hypertension

We evaluated the effects of FR901533, endothelin converting enzyme inhibitor, on development of right ventricular overload and medial thickening of pulmonary arteries in rats with monocrotaline-induced pulmonary hypertension. Pulmonary hypertension was induced by a single injection of monocrotaline (80 mg/kg). Twenty-four hours later (day 1), continuous subcutaneous injection of FR901533 (100 mg/kg/day) was started. Right ventricular systolic pressure, mass ratio of right ventricle to left ventricle, right ventricular wall thickness, right ventricular myocardial fiber diameter, percent medial thickness, and percent smooth muscle area in pulmonary arteries were significantly less in rats that received FR901533 than in the control with monocrotaline on day 28. Both immunoreactivities of endothelin-1 in pulmonary arteries and plasma endothelin-1 levels were observed significantly less in rats treated with FR901533 than in the control with monocrotaline. There were significant increased immunoreactivities of endothelin-B receptor in pulmonary arteries in rats that received FR901533 as compared with those in the control with monocrotaline. FR901533 (100 mg/kg/day), protected the development of right ventricular overload and medial thickening of pulmonary arteries in a rat model of pulmonary hypertension.

[Trial of new intraocular lens power calculation following phototherapeutic keratectomy]

We reviewed the SRK-II method and introduce a new equation to calculate the intraocular lens (IOL) power for eyes which underwent laser phototherapeutic keratectomy (PTK). The Gullstrand series was used to determine the power and the radius of curvature of planoconvex IOLs which alter the focal point from the cornea to reach the conjugate point on the retina. The radius of anterior corneal curvature (R), axial length (AXL), predicted postoperative anterior chamber depth (ACD), and lens thickness (LT) were employed in the following formula to calculate the IOL refractive power: K = R/7.7, DC = 337. 5/R, VC = 1,000/DC*1.336 where VC is the posterior vertex focal length. A1 = -(VC-ACD), B1 = AXL-0.5* K-ACD-0. 103 LT, S = 1/A1 + 1/B1; this determined the diopter (D) of IOL in liquid to be (D) = 1,000/(1/S)* 1.336. In eyes which underwent PTK, the keratometric value prior to cataract surgery was not applied. Instead, R' defined as R-dT, where R is the radius of corneal curvature prior to PTK and dT the amount of corneal tissue removed, was introduced. Further, the corneal thickness before cataract surgery (CT') was defined as CT-dT where CT is the corneal thickness prior to PTK. Although it is important to select a lens that has an acurate predicted anterior chamber depth, the new equation appears to be more useful than the SRK-II formula.

Adverse effects on rabbit anterior cruciate ligament after knee immobilization: changes in permeability of horseradish peroxidase

Changes in the permeability of horseradish peroxidase (HRP) and the histology of the rabbit anterior cruciate ligament (ACL) caused by knee immobilization were studied. The knees of adult rabbits were immobilized for 2-8 weeks by a long leg cast with the knee flexed at 120 degrees, and some joints were allowed to be remobilized for 4 weeks after 6 or 8 weeks' immobilization. After 1 ml of HRP was injected into the knee joint and allowed to permeate into the ACL, the degree of permeation at the mid-portion of the ACL between femur and tibia was visualized with diaminobenzidine tetrahydrochloride. The ACL was examined histologically by light and transmission electron microscopy. Although the HRP permeated into almost the entire area of the transverse section of the non-immobilized normal ACL, as the period of immobilization increased, the extent of permeation gradually decreased. The decrease was significant from week 4 to week 6 and from week 6 to week 8. Degenerative change with necrosis of cells at the central area of the ACL was noted in the 6-week immobilization group, and the 8-week period of immobilization increased the extent of this degeneration. Although the permeation recovered in both the 6-week and 8-week immobilization groups 4 weeks after remobilization, there were fewer cells with a normal morphology in the central area in the 8-week immobilization group than in the control. These results suggest that long-term immobilization adversely affects the ACL.

Adenosine A2A receptors modify motor function in MPTP-treated common marmosets

Both adenosine A1 and A2 receptor populations are located in the striatum and can modify locomotor activity, and they may form a therapeutic target for Parkinson's disease (PD). Administration of the selective adenosine A2A antagonist (E)-1,3-diethyl-8-(3,4-dimethoxystyryl)-7-methyl-3,7-dihydro-1H-pu rine-2,6-dione (KW-6002) to MPTP-treated common marmosets increased locomotor activity. In contrast, administration of the selective A1 receptor antagonist 1,3-dipropyl-8-cyclopentylxantine (DPCPX) had no effect on locomotion. Administration of the adenosine A2A receptor agonist 2-[p-[2-(2-aminoethylamino) carbonylethyl] phenethyl amino]-5'-N-ethylcarboxamidoadenosine (APEC) dose dependently suppressed basal locomotor activity. A minimally effective dose of APEC (0.62 mg/kg, i.p) completely reversed the increase in locomotor activity produced by administration of KW-6002. The adenosine A2A receptor appears to be an important target for the treatment of basal ganglia disorders, particularly PD.

Human papillomavirus oncoprotein E6 binds to the C-terminal region of human minichromosome maintenance 7 protein

Oncoprotein E6 of the human papillomavirus (HPV) associated with cervical cancer (HPV-16 and -18) degrades tumor suppressor protein p53, but seems to have p53-independent transforming functions. We searched for other cellular targets for the N-terminal region of HPV-16 E6 using a yeast two-hybrid system. The E6 was found to bind to the C-terminal region of a human minichromosome maintenance 7 (hMCM7) protein, which is a component of replication licensing factors. The full-length hMCM7 translated in vitro was capable of binding to bacterially expressed E6. In yeast cells the E6s of the cancer-associated HPVs (HPV-16, -18, and -58) bound to hMCM7 more strongly than those of the HPVs associated with a benign tumor (HPV-6 and -11). Binding of E6 with hMCM7 may cause chromosomal abnormalities found in the human cells expressing E6s of oncogenic HPVs.

Induction of virus-induced IDDM in virus resistant mice without lymphocyte maturation

The role of lymphocytes in the pathogenesis of viral-induced insulin dependent diabetes mellitus (IDDM) is controversial. To better understand how a virus-induced IDDM depends on the infiltrating lymphocytes, encephalomyocarditis virus (EMCV) was inoculated intraperitoneally into three kinds of mice; virus-susceptible C57BL/6, virus-resistant 129/SV and recombination activity gene-2 (Rag2) knockout 129/SV mice. Pancreatic inflammation and beta cell necrosis were evaluated after EMCV, D variant (10(3) pfu/mouse) inoculation. On post-inoculation day 14, the lethal rates of C57BL/6, 129/SV and Rag2 knockout mice were 52, 10 and 100%, respectively. The blood glucose in Rag2KO mice on day 8 was significantly elevated as compared with 129SV mice (231 +/- 49 vs 169 +/- 32 mg/dl, P<0.05). In situ hybridization demonstrated the EMCV genome in the pancreas of Rag2 knockout and C57BL/6 mice, but not in 129/SV mice. Beta cell necrosis were more severe in Rag-2 knockout mice than in wild type 129/SV mice, but lymphocyte infiltration was less severe than C57BL/6. Pancreas in Rag2 knockout mice infected with virus were affected more severely than the virus-resistant strain of mice. Diabetogenic virus induced IDDM in virus-resistant mice without mature lymphocytes.

The somatostatin analog, octreotide, inhibits in vitro outgrowth of smooth muscle cells from canine coronary and carotid atherosclerotic plaque tissues

Restenosis is caused by excessive neointima formation resulting from smooth muscle cell (SMC) proliferation and migration from the arterial media into the subendothelial space, stimulated by growth factors. A long-acting somatostatin analog, octreotide, activates protein tyrosine phosphatases and can inhibit the stimulatory effects of growth factors. In this study, we evaluated the effect of octreotide on SMC outgrowth from in vitro explants of both coronary and carotid arterial tissues in a canine endothelium-injury model. After 6 days of culture, SMC grew out of 33.3% and 58.3% of the explants from the injured canine carotid and coronary arterial tissues, respectively. In contrast, SMC outgrowth was not observed from any of the explants from normal canine carotid arterial tissue. Octreotide completely inhibited SMC outgrowth from injured canine carotid arterial tissue at a concentration of 10(-6) M. This agent also inhibited SMC outgrowth from injured canine coronary arterial tissue by 57% and 71% of the control value at concentrations of 10(-8) M and 10(-6) M, respectively. We conclude that our explant cell-culture model may prove to be valuable for assessing the effect of agents designed to reduce intimal proliferation, and that the use of the somatostatin analog octreotide in clinical settings may modify the high incidence of restenosis after coronary interventions by reducing SMC proliferation.

Inhibitory effects of apple polyphenol on induced histamine release from RBL-2H3 cells and rat mast cells

The anti-allergic activities of polyphenol fractions extracted from immature fruits of apple (Rosaceae, Malus sp.) were evaluated by in vitro assays. A crude apple polyphenol (CAP) fraction, which had been obtained from the juice of immature apples by reverse-phase column chromatography, was further purified by LH-20 column chromatography to obtain an apple condensed tannin (ACT) fraction consisting of linear oligomeric epicatechins from the dimer to pentadecamer. ACT strongly inhibited the release of histamine from rat basophilic leukemia (RBL-2H3) cells stimulated by the antigen-stimulation and from rat peritoneal mast cells stimulated by compound 48/80. The IC50 values for histamine release were 30 micrograms/ml and 25 micrograms/ml, respectively. ACT also inhibited hyaluronidase activity and the increase in intracellular free calcium concentration in RBL-2H3 cells stimulated with the antigen. These results suggest that ACT affected early signal transduction including the calcium influx.

Determination of antipituitary antibody in patients with endocrine disorders by enzyme-linked immunosorbent assay and Western blot analysis

The identification of pituitary antigens recognized by human antipituitary antibodies (APAs) is important in evaluating the pathophysiology of multiendocrine disorders linked to autoimmune factors. However, there is no convenient method for the quantitative analysis of circulating APAs. This study reports the development of an enzyme-linked immunosorbent assay (ELISA) for the detection of APAs. APAs were measured by ELISA and confirmed by Western blot analysis in sera from patients with endocrine disorders. APAs were detected frequently in patients with autoimmune thyroiditis, insulin-dependent diabetes mellitus (IDDM), or pituitary dwarfism. Circulating APAs were detected in 18% of patients with autoimmune thyroiditis. Confirmation by Western blot revealed positivity for APAs in the serum of 36% of patients with Hashimoto disease and in 29% of patients with Graves disease. Notably, 39% of patients with IDDM were also positive for APAs by ELISA. The identification of APAs by ELISA may be useful in evaluating autoimmune mechanisms involved in patients with multiendocrine disorders.

Pioglitazone enhances splanchnic glucose uptake as well as peripheral glucose uptake in non-insulin-dependent diabetes mellitus. AD-4833 Clamp-OGL Study Group

To evaluate the effect of pioglitazone on insulin resistance in non-insulin-dependent diabetes mellitus (NIDDM) patients, a double-blind placebo-controlled trial was carried out with 30 NIDDM patients. Twenty-one subjects, three on diet alone and 18 on sulfonylurea (SU), orally received 30 mg pioglitazone once daily for 12 weeks. Nine subjects, one on diet alone and eight on SU, received a matching placebo once daily for 12 weeks. Euglycemic (5.2 mmol/l) hyperinsulinemic (1200 pmol/l) clamp combined with an oral glucose load (OGL) was performed before and after 3-month treatment with pioglitazone or placebo to determine insulin-stimulated glucose disposal and splanchnic glucose uptake (SGU). No significant differences existed in the patients' characteristics, including age and body mass index, between the two study groups. The pioglitazone treatment increased the mean glucose infusion rate (GIR) prior to OGL from 8.2 +/- 2.2 to 9.2 +/- 2.0 mg/kg.min (mean +/- SD, P = 0.003) and increased the SGU rate from 28.5 +/- 19.4 to 59.4 +/- 27.1% (P = 0.010). The placebo treatment produced no significant changes in either GIR or SGU after treatment. A significant difference (P = 0.042) was observed in change of SGU between the pioglitazone and placebo treatment groups. In conclusion, the results indicate that pioglitazone is effective for ameliorating insulin resistance in NIDDM by enhancing SGU as well as peripheral glucose uptake.

A surface immunodeterminant of human papillomavirus type 16 minor capsid protein L2

We used human papillomavirus type 16 (HPV-16) particles composed of capsid proteins L1 and L2 (L1/L2 capsids) as an antigen to produce mouse monoclonal antibodies (MAbs). Of 18 MAbs recognizing surface epitopes of L1/L2 capsids, 1 was an anti-L1 MAb and 17 were anti-L2 MAbs. Seven of 11 anti-L2 MAbs recognizing linear epitopes wer found to bind to a synthetic peptide with an HPV-16 L2 sequence of amino acids (aa) 69-81, which is within a highly conserved region among different HPVs. The synthetic peptide reacted with the human sera that had been shown to be positive for an antibody against HPV-16, -18, -58, or -6b capsids composed of L1 alone. The data suggest that the HPV-16 L2 region of aa 69-81 contains a type-common immunodeterminant exposed on the surface of HPV virions.

Studies on circulating anti-pituitary antibodies in NIDDM patients

The clinical significance of anti-pituitary antibodies (APA) was examined by enzyme-linked immunosorbent assay (ELISA) in individuals with non-insulin dependent diabetes mellitus (NIDDM). Serum samples were obtained from 150 NIDDM patients and 45 normal subjects. Urinary C-peptide (U-CPR) was also measured for the NIDDM patients. APA-positive serum was incubated with porcine pancreas, liver, kidney, or spleen powder and analyzed by immunoblot. The prevalence of APA was found to be significantly (P<0.05) higher in NIDDM patients (24.7%) than in the controls (6.7%) by ELISA. The index values for APA were inversely related to the levels of U-CPR (P<0.005). The levels of U-CPR were significantly (P<0.0001) lower and the prevalence of insulin deficiency was significantly (P<0.05) higher in NIDDM patients who were APA positive than in those who were APA negative. The presence of APA may therefore be related to reduced secretion of insulin in NIDDM patients. In Western blot analysis, preincubation of APA-positive sera with porcine pancreas powder prevented recognition of the 22-kD protein (APA). The possibility of a common autoantigenicity in the pancreas and the pituitary was indicated.

Impaired expression of atrial natriuretic peptide in diabetic rats with myocardial infarction

We evaluated the effects of myocardial infarction (MI) on the hemodynamics and the expression of atrial natriuretic peptide (ANP) mRNA in rats with streptozotocin-induced diabetes. Eight weeks after streptozotocin injection, the diabetic rats and age-matched nondiabetic controls underwent coronary artery ligation. One week later, the left ventricular end-diastolic pressure, systolic blood pressure, infarct size, and serum ANP levels did not differ significantly between the diabetic and nondiabetic rats. Compared with control animals without MI, the atrial ANP/beta-actin mRNA ratio in rats with MI was increased to 195% in diabetic animals and 213% in nondiabetic animals. In the left ventricle, however, the ANP/beta-actin mRNA ratio in diabetic animals with MI was increased to only 131% compared with control animals, whereas the corresponding increase in nondiabetic animals was 240% (p<0.05). Thus, the modulation of ANP mRNA expression after MI was impaired in the left ventricle, but not in the atria, of diabetic rats. A reduced myocardial expression of ANP could increase the morbidity and mortality associated with cardiovascular disorders in patients with diabetes.

Activated protein C resistance assay as a screening test for thromboembolic disposition

An activated partial thromboplastin time (APTT) based method was developed to determine the anticoagulant response in patient plasma to added purified activated protein C (APC). On the other hand, Bertina et al. (1994) reported that one point mutation of amino acid 506 in the factor V was observed in such APC resistance patients. APC resistance for blood samples with known abnormal findings on the coagulation test also may be determined. Coagmaster II for the APTT assay system (Sankyo, Tokyo, Japan) was employed. The APC resistance assay system was a useful reagent as a screening test for lupus anticoagulant (LA), in addition to APC resistance.

Reduced serum T3 level in a patient with nodular goiter and cardiac myxoma

We report the unusual case of an 87-year-old woman with cardiac myxoma and adenomatous goiter. She exhibited slight elevations of serum interleukin-6 (IL-6), but levels of thyroid hormones such as T3, free T3 and free T4 were all abnormally low. Interleukin-6 may potentiate the alteration of thyroid metabolism.

Removing tRNA from a cell-free protein synthesis system for use in protein production

The cell-free system for biosynthesis of proteins is becoming an important tool for protein engineering. In particular, introduction of the unnatural amino acids is achieved though cell-free protein synthesis with the use of chemically acylated tRNA that recognizes a specific codon. In the original method, however, it was difficult to control the system through changing tRNA composition, as the endogenous tRNAs are involved in the reaction. Thus, in the present study, we digested the tRNA within Escherichia coli S30 extract with resin-bound RNase A, and estimated the protein synthesis activity. It was revealed that this digestion process does not damage the activity, if a protease inhibitor, phenylmethylsulfonyl fluoride (PMSF), is present in the digestion reaction.

Retroviral vector targeting human cells via c-Kit-stem cell factor interaction

Targeted gene transfer into hematopoietic stem cells by retroviral vectors would greatly facilitate the development of in vivo strategies for stem cell gene therapy. We engineered a recombinant retroviral vector that can target human cells expressing a c-Kit receptor via a ligand-receptor interaction. The ecotropic (Moloney murine leukemia virus) envelope protein was modified by insertion of a sequence encoding the N-terminal 161 amino acids of murine stem cell factor (mSCF), the ligand for murine c-Kit. The chimeric envelope protein was correctly processed and incorporated into viral particles as efficiently as the wild-type envelope protein. Virions pseudotyped with the chimeric envelope proteins bound to 293 cells expressing murine c-Kit (293KIT) preferentially; however, they could not transduce any c-Kit-positive cells under conventional conditions. They could transduce 293KIT cells in the presence of chloroquine, and HEL cells expressing human c-Kit on a fibronectin fragment (CH296)-coated dish. The fact that recombinant mSCF in the medium at the time of transduction greatly reduced the efficiency of both gene deliveries implies that the vector utilized the mSCF-c-Kit interaction for the initial step of transduction in either case. The vector may prove useful for targeting cells expressing c-Kit on their surface.

Type V phosphodiesterase inhibition modulates endogenous immunoreactivities of endothelin-1 and endothelial nitric oxide synthase in pulmonary arteries in rats with monocrotaline-induced pulmonary hypertension

We evaluated the effects of oral administration of E4021 (100 mg/kg/day), a type V phosphodiesterase inhibitor, on immunoreactivities of endothelin-1, endothelin receptors, and nitric oxide synthases in pulmonary arteries in a rat model of pulmonary hypertension. Immunoreactivities of endothelin-1 and endothelial nitric oxide synthase were observed significantly less frequently, together with significant reduction of right ventricular overload and medial thickening in rats treated with E4021 than in the control with monocrotaline on day 28. The levels of plasma endothelin-1 and serum nitrite and nitrate were significantly lower in rats that received E4021 than in the control with monocrotaline. Oral administration of E4021 modulates endogenous immunoreactivities of endothelin-1 and endothelial nitric oxide synthase with the improvement or right ventricular overload and medial thickening.