Comparison of quality of life and activity of daily living status of patients with myasthenia gravis treated with low-dose and high-dose prednisolone.

OBJECTIVES: To compare the effect of low-dose prednisolone (PSL) (≤5 mg/day) and high-dose PSL (>5 mg/day) therapy on the QOL and activity of daily living (ADL) in patients with MG. METHODS: A total of 679 patients with MG underwent a survey using Japanese versions of the MG-QOL 15-J and MG-ADL scales. Higher scores of these scales suggest deterioration of the QOL and ADL, respectively. RESULTS: The total MG-QOL 15-J scores of the high-dose group (27.0±13.8) were significantly higher than those of the low-dose group (20.9±14.6). Similarly, the total MG-ADL scores of the high-dose group (6.3±4.1) were significantly higher than those of the low-dose group (5.3±4.1). CONCLUSION: These results showed that the QOL of patients in the low-dose group appeared better than that in the high-dose group. Low-dose PSL therapy may help achieve minimal manifestations level in Japanese patients with MG.

Survey of satisfaction regarding palliative care provided to patients who died at home or in a hospital.

BACKGROUND: Improvement in quality of life (QoL) of patients is one of the most important goals of palliative care, but evaluation of QoL of patients is difficult. AIM: To evaluate QoL of patients who died at home or in a hospital. METHODS: We administered the Good Death Inventory (10 core and 8 optional domains) to the bereaved families of patients who died at home or in a hospital. A total of 107 bereaved families undertook a survey. FINDINGS: If a bereaved family chose 'somewhat agree', 'agree' or 'absolutely agree', the answer was regarded as a 'satisfactory answer'. Regarding the 10 core domains, of patients who died in a hospital, <50% respondents gave a 'satisfactory answer' to three questions, whereas of patients who died at home, >60% of respondents gave a 'satisfactory answer' to seven questions. Regarding the eight optional domains, of patients who died in a hospital, <50% respondents gave a 'satisfactory answer' to five questions, whereas of patients who died at home, >60% of respondents gave a 'satisfactory answer' to four questions. CONCLUSIONS: QoL of patients who died at home appeared higher than that of those who died in a hospital. Patients prefer to remain at home rather than in a hospital, probably because at home they are surrounded by familiar things and can live according to their usual habits.

The exacerbating roles of CCAAT/enhancer-binding protein homologous protein (CHOP) in the development of bleomycin-induced pulmonary fibrosis and the preventive effects of tauroursodeoxycholic acid (TUDCA) against pulmonary fibrosis in mice.

The purpose of this study was to evaluate the role of CCAAT/enhancer-binding protein homologous protein (CHOP), an important transcription factor that regulates the inflammatory reaction during the endoplasmic reticulum (ER) stress response, in the development of pulmonary fibrosis induced by bleomycin (BLM) in mice. An intratracheal injection of BLM transiently increased the expression of CHOP mRNA and protein in an early phase (days 1 and 3) in mice lungs. BLM-induced pulmonary fibrosis was significantly attenuated in Chop gene deficient (Chop KO) mice, compared with wild-type (WT) mice. Furthermore, the inflammatory reactions evaluated by protein concentration, the total number of leucocytes and neutrophils in the bronchoalveolar lavage fluid (BALF), the mRNA expression of interleukin 1b and caspase 11, and the apoptotic cell death were suppressed in Chop KO mice compared with those in WT mice. In addition, administration of tauroursodeoxycholic acid (TUDCA), a pharmacological agent that can inhibit CHOP expression, inhibited the BLM-induced pulmonary fibrosis and inflammation, and the increase in Chop mRNA expression in WT mice in a dose-dependent manner. These results suggest that the ER stress-induced transcription factor, CHOP, at least in part, plays an important role in the development of BLM-induced pulmonary fibrosis in mice, and that the inhibition of CHOP expression by a pharmacological agent, such as TUDCA, may be a promising strategy for the prevention of pulmonary fibrosis.

An evaluation of novel biological activity in a crude extract from Hemerocallis fulva L. var. sempervirens M. Hotta.

Hemerocallis fulva L. var. sempervirens M. Hotta (kwanso) represents an exceptional resource for identifying and developing new phytomedicines for the treatment and prevention of disease. The aim of this study was to conduct a detailed investigation of the biological activities of kwanso. Our study resulted in four major findings. First, kwanso scavenges hydroxyl radicals generated by H(2)O(2)/UV light system in vitro in a dose-dependent manner. Second, hepatic glutathione levels were significantly increased when kwanso was orally administered to mice. Third, the oral administration of kwanso to mice showed a tendency to suppress hepatic injury induced by acetaminophen. Finally, kwanso slightly inhibited cytochrome P450 3A activity. These results provide useful evidence in support of the development of kwanso as a candidate raw material for the treatment and prevention of disease.

Possible false-negative results on therapeutic drug monitoring of phenytoin using a particle enhanced turbidimetric inhibition immunoassay in a patient with a high level of IgM.

: In this report, the authors described the unusual case of a patient in whom the plasma phenytoin concentration was unexpectedly not detected on a particle-enhanced turbidimetric inhibition immunoassay (PETINIA) technique, a typical immunoassay for phenytoin. The plasma concentration was measured using PETINIA and high-performance liquid chromatography in a 69-year-old male patient treated with fosphenytoin intravenously at the standard dose for 7 days. Although the plasma concentration of phenytoin was below the limit of detection (<0.5 mcg/mL) on PETINIA after the administration of fosphenytoin, the trough plasma concentration was estimated to be between 5 and 10 mg/L on high-performance liquid chromatography. When the plasma concentrations of IgM and IgG were measured using an enzyme-linked immunosorbent assay, the plasma IgG level was within the reference range, whereas the plasma IgM level was 2-3 times higher than the upper limit of the reference range. We concluded that the PETINIA method yielded a possible false-negative result regarding the phenytoin level in this patient, perhaps because of some hindrance to the measurement process by IgM. This case suggests that false-negative results should be considered when therapeutic drug monitoring reveals abnormally low values using PETINIA and that it is necessary to evaluate the plasma IgM level.

Aminophylline, administered at usual doses for rodents in pharmacological studies, induces hippocampal neuronal cell injury under low tidal volume hypoxic conditions in guinea-pigs.

OBJECTIVES: To establish whether aminophylline, administered at usual doses for rodents in pharmacological studies, induces brain injury in systemic hypoxaemia in guinea-pigs. METHODS: A hypoxaemia (partial oxygen tension of arterial blood (PaO2) = 40-60 mmHg) model was developed by low tidal volume mechanical ventilation in guinea-pigs. KEY FINDINGS: Under hypoxic conditions, aminophylline significantly increased the concentration of brain-specific creatine kinase in the serum in a dose- and time-dependent manner. A reduced number of hippocampal neuronal cells in the CA1 region, an increase in the concentration of neuron-specific enolase (NSE) in cerebrospinal fluid (CSF), an increase in lipid hydroperoxides and a decrease in the ratio of glutathione to glutathione disulfide in the brain tissues were also observed. These effects were not observed when aminophylline at the same doses was administered under normoxic conditions (PaO2 = 80-100 mmHg). There was no difference in either serum or CSF concentrations of theophylline between normoxic and hypoxic conditions. Another methylxanthine, caffeine, did not increase the concentration of NSE in CSF. CONCLUSIONS: Aminophylline potentially induces brain damage under hypoxic conditions. We suggest that aminophylline treatment has adverse effects in patients with hypoxaemia subsequent to respiratory disorders such as asthma.

Comparative Effects of Phosphoenolpyruvate, a Glycolytic Intermediate, as an Organ Preservation Agent with Glucose and N-Acetylcysteine against Organ Damage during Cold Storage of Mouse Liver and Kidney.

We evaluated the usefulness of phosphoenolpyruvate (PEP), a glycolytic intermediate with antioxidative and energy supplementation potentials, as an organ preservation agent. Using ex vivo mouse liver and kidney of a static cold storage model, we compared the effects of PEP against organ damage and oxidative stress during cold preservation with those of glucose or N-acetylcysteine (NAC). Lactate dehydrogenase (LDH) leakage, histological changes, and oxidative stress parameters (measured as thiobarbituric acid reactive substance and glutathione content) were determined. PEP (100 mM) significantly prevented an increase in LDH leakage, histological changes, such as tubulonecrosis and vacuolization, and changes in oxidative stress parameters during 72 h of cold preservation in mouse liver. Although glucose (100 mM) partly prevented LDH leakage and histological changes, no effects against oxidative stress were observed. By contrast, NAC inhibited oxidative stress in the liver and did not prevent LDH leakage or histological changes. PEP also significantly prevented kidney damage during cold preservation in a dose-dependent manner, and the protective effects were superior to those of glucose and NAC. We suggest that PEP, a functional carbohydrate with organ protective and antioxidative activities, may be useful as an organ preservation agent in clinical transplantation.

The relaxant action of nicorandil in bovine tracheal smooth muscle.

The relaxant mechanisms of nicorandil were examined by comparing its effects with those of sodium nitroprusside and cromakalim in bovine tracheal smooth muscle. In preparations contracted with methacholine (0.3 µ mol/l) or high K(+)(40 mmol/l), nicorandil and sodium nitroprusside caused concentration-dependent relaxations. Their relaxant effects on high K(+) -contracted preparations were smaller than those on methacholine-contracted muscle. Cromakalim relaxed methacholine-contracted preparations, whereas it had no effect on high K(+) -contracted muscle. The inhibitor of soluble guanylyl cyclase 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ; 5 mol/l) completely prevented the relaxation induced by lower concentrations ( <30 µ mol/l) of nicorandil,whereas it partially attenuated relaxation caused by higher concentrations. The ATP-sensitive K(+) (K(ATP)) channel blocker glibenclamide only partially attenuated the relaxant responses to nicorandil (at 100 and 300 µ mol/l). Combination treatment with ODQ and glibenclamide almost completely prevented nicorandil-induced relaxations. The large-conductance Ca2(+) -activated K(+) channel (Maxi K(+) channel) inhibitor iberiotoxin significantly prevented the relaxations induced by lower concentrations (3 and 10 µ mol/l) of nicorandil. The preventive effect of iberiotoxin was markedly enhanced under the blockade of K(ATP) channels with glibenclamide. These results suggest that nicorandil relaxes bovine tracheal smooth muscle through 2 mechanisms: opening of K(ATP) channels and activation of the nitric oxide (NO)-cyclic guanosine monophosphate (cGMP) pathway. Nicorandil may also activate Maxi K(+) channels, possibly through the NO-cGMP pathway, and the interaction of K ATP channels and Maxi K(+) channels may affect the relaxant effect of nicorandilin bovine tracheal smooth muscle.

The ethical Kampo formulation Sho-seiryu-to (TJ-19) prevents bleomycin-induced pulmonary fibrosis in rats.

The effects of Sho-seiryu-to (TJ-19), an ethical Kampo formulation, on bleomycin (BLM)-induced pulmonary fibrosis in rats was examined. Pulmonary fibrosis was induced by intratracheal instillation of a single dose of BLM (5 mg/kg). The TJ-19 used consisted of at least 21 constituents, as determined by three-dimensional HPLC analysis, and was administered orally twice a day at a dose of 1.5 g/kg until the end of the study period. Changes in general appearance and body weight were monitored. Twenty-eight days after BLM instillation, the animals were sacrificed and the study parameters were measured. TJ-19 attenuated the loss in body weight, increase in lung/body weight ratio and concentration of hydroxyproline and malondialdehyde in the lung tissues induced by BLM administration. TJ-19 also prevented BLM-induced fibrotic changes in the lung histology. These protective effects of TJ-19 were observed when administration was started 1 week before and simultaneously with the instillation of BLM. These results suggest that TJ-19 has prophylactic potential against BLM-induced pulmonary fibrosis, and may therefore be a promising drug candidate and medicinal resource for preventing BLM-induced and idiopathic pulmonary fibrosis.

The effects of single nucleotide polymorphisms in CYP2A13 on metabolism of 5-methoxypsoralen.

A number of studies have demonstrated that cytochrome P450 (P450) converts furanocoumarin derivatives into reactive molecules, which form covalent bonds to biomolecules. 5-Methoxypsoralen (5-MOP) is a natural furanocoumarin from apiaceous plants. In this study, we examined the effect on 5-MOP metabolism of single nucleotide polymorphisms (SNPs) in CYP2A13. We used Escherichia coli-generated recombinant enzymes of wild-type CYP2A13*1 and five variants, CYP2A13*4 (R101Q), CYP2A13*5 (F453Y), CYP2A13*6 (R494C), CYP2A13*8 (D158E), and CYP2A13*9 (V323L). In high-performance liquid chromatography analyses of 5-MOP metabolic products, CYP2A13*1 converted 5-MOP into 5-MOP dihydrodiol; K(m) and V(max) values of the reaction were 1.44 ± 0.17 µM and 4.23 ± 0.36 nmol/(min · nmol P450), respectively. The generation of a dihydrodiol from 5-MOP implies that conversion by CYP2A13 causes toxicity due to the formation of covalent bonds with DNA or proteins. Most of the CYP2A13 variants could metabolize 5-MOP; K(m) values for CYP2A13*5, *6, *8, and *9 were 1.63 ± 0.12, 1.36 ± 0.10, 0.85 ± 0.09, and 0.58 ± 0.06 µM, respectively, and V(max) values were 3.20 ± 0.13, 4.69 ± 0.13, 2.34 ± 0.07, and 1.84 ± 0.09 nmol/(min · nmol P450), respectively. However, the processing of 5-MOP by CYP2A13*4 was not detectable. Based on this data, we hypothesize that SNPs within the CYP2A13 gene affect metabolism of 5-MOP in humans.

A selective thromboxane A2 (TXA2) synthase inhibitor, ozagrel, attenuates lung injury and decreases monocyte chemoattractant protein-1 and interleukin-8 mRNA expression in oleic acid-induced lung injury in guinea pigs.

This study examined the effect of ozagrel, a thromboxane A(2) synthase inhibitor, on the accumulation of leucocytes and chemokine mRNA expression in lungs experimentally injured using oleic acid (OA). OA injection into guinea pigs rapidly increased thromboxane A(2) generation and subsequently increased total protein concentration and the numbers of macrophages and neutrophils in bronchoalveolar lavage fluid and increased monocyte chemoattractant protein-1 and interleukin-8 mRNA expression in the whole lung. Administration of ozagrel prevented these changes associated with OA injection. Ozagrel is a promising drug candidate for preventing acute lung injury.

Protection afforded by a herbal medicine, Sho-seiryu-to (TJ-19), against oleic acid-induced acute lung injury in guinea-pigs.

OBJECTIVES: The effect of a herbal medicine, Sho-seiryu-to (TJ-19), on oleic acid-induced lung injury, an animal model of acute respiratory distress syndrome or acute lung injury (ARDS/ALI), was examined. METHODS: Acute lung injury was induced by an intravenous injection of 15 microl/kg oleic acid to guinea-pigs. TJ-19 was administered by a single oral dose (3 g/kg) or by multiple oral doses (0.75 g/kg). KEY FINDINGS: The decrease in partial oxygen pressure of arterial blood (Pao(2)) and the increase in airway vascular permeability induced by the oleic acid injection were attenuated by a single dose of TJ-19. When TJ-19 was administered orally twice a day for two weeks and then oleic acid was injected, a potent prophylactic effect of the drug was observed. TJ-19 also prevented airway vascular hyperpermeability, lung cell injury, oxidative stress and thromboxane A(2) generation, associated with the oleic acid injection. CONCLUSIONS: TJ-19 significantly attenuated the oleic acid-induced lung injury probably through the antioxidative effect and inhibitory effect of thromboxane A(2) generation, although the precise inhibitory mechanisms were not fully elucidated due to the diversity in constituents of the herbal medicine. We suggest that TJ-19 is a promising drug candidate and a medicinal resource for preventing ARDS/ALI.

Effects of bolus injection of soybean-based fat emulsion and fatty acids on pulmonary gas exchange function.

To determine whether or not a "bolus injection" of soybean-based fat emulsion (SFE), which contains oleic acid (OA), a potent lung-toxic unsaturated C-18 fatty acid, can induce pulmonary dysfunction, we examined the effect of SFE injection on the partial oxygen pressure of arterial blood (Pao2) and pulmonary vascular permeability. In addition, we compared the effect of an injection of SFE with that of OA, soybean oil (a source of SFE), emulsified OA and C-18 fatty acids. Bolus injection of SFE (0.3-4.8 ml/kg) had little effect on Pao2) and pulmonary vascular permeability. Injection of an equivalent amount of OA, on the other hand, significantly decreased Pao2 and increased pulmonary vascular hyper-permeability. This decrease in Pao2 was attenuated by emulsification. Unemulsified soybean oil also induced a decrease in Pao2, although the effect was weaker than that of OA. Other unsaturated C-18 fatty acids (linoleic and linolenic acid) induced a decrease in Pao2 as potent as OA while stearic acid, a C-18 saturated fatty acid, had little effect. Although we did not observe pulmonary toxicity as a result of "bolus injection" of SFE, the chemical form, for example, emulsification and the degree of saturability of the carbon chain, seems to influence the pulmonary toxicities of lipids and fatty acids. Furthermore, the potent pulmonary toxicity of OA seems to depend not only on pulmonary vascular embolization but also pharmacological and/or inflammation-inducing properties.

Molecular characterization of a novel type of prostamide/prostaglandin F synthase, belonging to the thioredoxin-like superfamily.

Prostaglandin F (PGF) ethanolamide (prostamide F) synthase, which catalyzed the reduction of prostamide H(2) to prostamide F(2alpha), was found in mouse and swine brain. The enzyme was purified from swine brain, and its amino acid sequence was defined. The mouse enzyme consisted of a 603-bp open reading frame coding for a 201-amino acid polypeptide with a molecular weight of 21,669. The amino acid sequence placed the enzyme in the thioredoxin-like superfamily with Cys(44) being the active site. The enzyme expressed in Escherichia coli as well as the native enzyme catalyzed not only the reduction of prostamide H(2) to prostamide F(2alpha) but also that of PGH(2) to PGF(2alpha). The V(max) and K(m) values for prostamide H(2) were about 0.25 micromol/min.mg of protein and 7.6 microm, respectively, and those for PGH(2) were about 0.69 micromol/min.mg of protein and 6.9 microm, respectively. Neither PGE(2) nor PGD(2) served as a substrate for this synthase. Based on these data, we named the enzyme prostamide/PGF synthase. Although the enzyme showed a broad specificity for reductants, reduced thioredoxin preferentially served as a reducing equivalent donor for this enzyme. Moreover, Northern and Western blot analyses in addition to the prostamide F synthase activity showed that the enzyme was mainly distributed in the brain and spinal cord, and the immunohistochemical study in the spinal cord showed that the enzyme was found mainly in the cytosol. These results suggest that prostamide/PGF synthase may play an important functional role in the central nervous system.

Preclinical investigation of the topical administration of phenserine: transdermal flux, cholinesterase inhibition, and cognitive efficacy.

Phenserine (PS) was designed as a selective acetylcholinesterase (AChE) inhibitor, with a tartrate form (PST) for oral administration in mild to moderate Alzheimer's disease (AD). Recent phase 3 trials of PST in Europe indicate that any clinically relevant activity of PST may be limited by its duration of action. Like many oral drugs, bioavailability and plasma concentrations of PST are regulated by hepatic and gastrointestinal first-pass effects. To minimize the kinetic limitations of first-pass metabolism, transdermal formulations of PS and PST (ointment/patch) were developed and characterized in vitro and in vivo. Initial in vitro kinetic characterization of PS or PST formulations used a diffusion cell chamber and skin samples isolated from hairless mice. Liquid paraffin and fatty alcohol/propylene glycol (FAPG) were found to be suitable vehicles for ointment formulation. Addition of a penetration enhancer, 1-[2-(decylthio)ethyl]-azacyclopentane-2-one (HPE-101), improved stratum corneum permeability. Application of the optimal formulation of PS/HPE-101/FAPG to the shaved back of rats resulted in significantly lowered plasma and brain AChE activities and improved cognitive performance in animals with scopolamine-induced cognitive impairment. These results suggest that the transdermal application of AChE inhibitors may represent an effective therapeutic strategy for AD. Particular benefits over oral therapies might include avoiding first-pass metabolic effects and improved dosing compliance.

Preventive effect of tranilast on oleic acid-induced lung injury in guinea pigs.

Acute respiratory distress syndrome or acute lung injury (ARDS)/(ALI) involve the severe lung injury with pulmonary vascular hyper-permeability and hypoxemia induced by inflammatory reactions. Since ARDS/ALI carries high mortality, the development of new drugs against ARDS/ALI is required. We examined the effect of tranilast, an anti-allergic drug, on vascular hyper-permeability in the lungs and airways, and on hypoxemia, in oleic acid (OA)-induced acute lung injury, an animal model of ARDS/ALI. The increase in pulmonary and airway vascular permeability and the decrease in partial oxygen pressure of arterial blood induced by an intravenous injection of OA were drastically ameliorated by the oral administration of tranilast in a dose-dependent manner. This is the first report to prove that tranilast prevents pulmonary and airway vascular permeability and hypoxemia induced by OA. These results suggest that tranilast may be a candidate drug for the treatment of ARDS/ALI.

Nuclear localization and interaction of RolB with plant 14-3-3 proteins correlates with induction of adventitious roots by the oncogene rolB.

The rooting-locus gene B (rolB) on the T-DNA of the root-inducing (Ri) plasmid in Agrobacterium rhizogenes is responsible for the induction of transformed adventitious roots, although the root induction mechanism is unknown. We report here that the RolB protein of pRi1724 (1724RolB) is associated with Nicotianatabacum14-3-3-like protein omegaII (Nt14-3-3 omegaII) in tobacco bright yellow (BY)-2 cells. Nt14-3-3 omegaII directly interacts with 1724RolB protein. Green fluorescent protein (GFP)-fused 1724RolB is localized to the nucleus. GFP-fused mutant 1724RolB proteins having a deletion or amino acid substitution are unable to interact with Nt14-3-3 omegaII and also show impaired nuclear localization. Moreover, these 1724RolB mutants show decreased capacity for adventitious root induction. These results suggest that adventitious root induction by 1724RolB protein correlates with its interaction with Nt14-3-3 omegaII and the nuclear localization of 1724RolB protein.

Involvement of thromboxane A2 (TXA2) in the early stages of oleic acid-induced lung injury and the preventive effect of ozagrel, a TXA2 synthase inhibitor, in guinea-pigs.

An intravenous injection of oleic acid into animals can produce a lung injury with hypoxaemia and pulmonary vascular hyper-permeability. Although oleic acid lung injury is used as a model of acute respiratory distress syndrome (ARDS), the precise mechanisms of the lung injury are still unclear. We have investigated whether thromboxane A(2) (TXA(2)) participated in the lung injury and have evaluated the efficacy of ozagrel, a TXA(2) synthase inhibitor, on the lung injury in guinea-pigs. Oleic acid injection increased the plasma level of TXB(2), a stable metabolite of TXA(2), and the time-course of plasma TXB(2) was similar to that of the decreased partial oxygen pressure of arterial blood (Pao(2)) induced with oleic acid. Ozagrel administered intravenously 30 min before oleic acid injection prevented the decrease in Pao(2) and pulmonary vascular hyper-permeability. It also prevented increases in lactate dehydrogenase activity, a measure of lung cell injury, TXB(2 )and its weight ratio to 6-keto prostaglandin F(1alpha) in bronchoalveolar lavage fluid. Although ozagrel administered simultaneously with oleic acid ameliorated the decrease in Pao(2), post treatment showed little effect. We suggest that TXA(2) participated in the oleic acid lung injury, as an "early phase" mediator, and rapidly-acting TXA(2) synthase inhibitors were effective in the prevention of acute lung injury.

Relaxant effect of YM976, a novel phosphodiesterase 4 inhibitor, on bovine tracheal smooth muscle.

Effects of 4-(3-chlorophenyl)-1,7-diethylpyrido[2,3-d]pyrimidin-2(1H)-one (YM976), a novel and selective phosphodiesterase type 4 inhibitor, on tension and adenosine 3',5'-cyclic monophosphate (cAMP) content of bovine tracheal smooth muscle were compared with those of rolipram and theophylline. YM976, rolipram and theophylline relaxed the tracheal preparations contracted with histamine in a concentration-dependent manner. The relaxant effects of YM976 and rolipram were more potent than those of theophylline. These phosphodiesterase inhibitors-induced relaxations were dramatically diminished when tracheal smooth muscle was contracted with methacholine instead of histamine. Pretreatment of the tracheal preparations with YM976 (10 microM) or rolipram (10 microM), but not with theophylline (1 mM), shifted the concentration-response curves for contractile responses to histamine; however, the same procedure failed to affect concentration-response relationships for methacholine-induced contractions. At 1 and 10 microM, both YM976 and rolipram increased the tissues cAMP content. These results suggest that YM976 relaxes tracheal smooth muscle, probably through the cAMP-dependent mechanism.