Effects of a prostagrandin EP4-receptor agonist ONO-AE1-329 on the left ventricular pressure-volume relationship in the halothane-anesthetized dogs.

Cardiac effects of a prostagrandin EP4-receptor agonist ONO-AE1-329 were assessed in the halothane-anesthetized dogs under the monitoring of left ventricular pressure-volume relationship, which were compared with those of clinically recommended doses of dopamine, dobutamine and milrinone (n=4-5 for each treatment). ONO-AE1-329 was intravenously administered in doses of 0.3, 1 and 3 ng/kg/min for 10 min with a pause of 20 min. Dopamine in a dose of 3 µg/kg/min for 10 min, dobutamine in a dose of 1 µg/kg/min for 10 min and milrinone in a dose of 5 µg/kg/min for 10 min followed by 0.5 µg/kg/min for 10 min were intravenously administered. Low dose of ONO-AE1-329 increased the stroke volume. Middle dose of ONO-AE1-329 increased the cardiac output, left ventricular end-diastolic volume, ejection fraction, maximum upstroke/downstroke velocities of the left ventricular pressure and external work, but decreased the end-systolic pressure and internal work besides the change by the low dose. High dose of ONO-AE1-329 increased the heart rate and maximum elastance, but decreased the end-systolic volume besides the changes by the middle dose. Dopamine, dobutamine and milrinone exerted essentially similar cardiac effects to ONO-AE1-329, but they did not significantly change the end-diastolic volume, end-systolic volume, stroke volume, ejection fraction, end-systolic pressure, maximum elastance, external work or internal work. Thus, EP4-receptor stimulation by ONO-AE1-329 may have potential to better promote the passive ventricular filling than the conventional cardiotonic drugs, which could become a candidate of novel therapeutic strategy for the treatment of heart failure with preserved ejection fraction.

Effects of ONO-6950, a novel dual cysteinyl leukotriene 1 and 2 receptors antagonist, in a guinea pig model of asthma.

We assessed in this study the anti-asthmatic effects of ONO-6950, a novel cysteinyl leukotriene 1 (CysLT1) and 2 (CysLT2) receptors dual antagonist, in normal and S-hexyl glutathione (S-hexyl GSH)-treated guinea pigs, and compared these effects to those of montelukast, a CysLT1 selective receptor antagonist. Treatment with S-hexyl GSH reduced animals LTC4 metabolism, allowing practical evaluation of CysLT2 receptor-mediated airway response. ONO-6950 antagonized intracellular calcium signaling via human and guinea pig CysLT1 and CysLT2 receptors with IC50 values of 1.7 and 25 nM, respectively (human receptors) and 6.3 and 8.2 nM, respectively (guinea pig receptors). In normal guinea pigs, both ONO-6950 (1 or 0.3 mg/kg, p.o.) and the CysLT1 receptor antagonist montelukast (0.3 or 0.1 mg/kg, p.o.) fully attenuated CysLT1-mediated bronchoconstriction and airway vascular hyperpermeability induced by LTD4. On the other hand, in S-hexyl GSH-treated guinea pigs ONO-6950 at 3 mg/kg, p.o. or more almost completely inhibited bronchoconstriction and airway vascular hyperpermeability elicited by LTC4, while montelukast showed only partial or negligible inhibition of these airway responses. In ovalbumin sensitized guinea pigs, treatment with S-hexyl GSH on top of pyrilamine and indomethacin rendered antigen-induced bronchoconstriction sensitive to both CysLT1 and CysLT2 receptor antagonists. ONO-6950 strongly inhibited this asthmatic response to the level attained by combination therapy with montelukast and BayCysLT2RA, a selective CysLT2 receptor antagonist. These results clearly demonstrate that ONO-6950 is an orally active dual CysLT1/LT2 receptor antagonist that may provide a novel therapeutic option for patients with asthma.

Discovery of Gemilukast (ONO-6950), a Dual CysLT1 and CysLT2 Antagonist As a Therapeutic Agent for Asthma.

An orally active dual CysLT1 and CysLT2 antagonist possessing a distinctive structure which consists of triple bond and dicarboxylic acid moieties is described. Gemilukast (ONO-6950) was generated via isomerization of the core indole and the incorporation of a triple bond into a lead compound. Gemilukast exhibited antagonist activities with IC50 values of 1.7 and 25 nM against human CysLT1 and human CysLT2, respectively, and potent efficacy at an oral dose of 0.1 mg/kg given 24 h before LTD4 challenge in a CysLT1-dependent guinea pig asthmatic model. In addition, gemilukast dose-dependently reduced LTC4-induced bronchoconstriction in both CysLT1- and CysLT2-dependent guinea pig asthmatic models, and it reduced antigen-induced constriction of isolated human bronchi. Gemilukast is currently being evaluated in phase II trials for the treatment of asthma.

Cardiohemodynamic and electrophysiological effects of a selective EP4 receptor agonist ONO--AE1--329 in the halothane-anesthetized dogs.

Cardiovascular effects of a highly selective prostaglandin E2 type 4 (EP4) receptor agonist ONO-AE1-329 were assessed with the halothane-anesthetized dogs (n=6). ONO-AE1-329 was intravenously infused in three escalating doses of 0.3, 1 and 3ng/kg/min for 10min with a pause of 20min between the doses. The low dose of 0.3ng/kg/min significantly increased maximum upstroke velocity of left ventricular pressure by 18% at 20min, indicating increase of ventricular contractility. The middle dose of 1ng/kg/min significantly decreased total peripheral resistance by 24% and left ventricular end-diastolic pressure by 32% at 10min, indicating dilation of arteriolar resistance vessels and venous capacitance ones, respectively; and increased cardiac output by 25% at 10min in addition to the change induced by the low dose. The high dose of 3ng/kg/min increased heart rate by 34% at 10min; decreased mean blood pressure by 14% at 10min and atrioventricular nodal conduction time by 13% at 5min; and shortened left ventricular systolic period by 8% at 10min and electromechanical coupling defined as an interval from completion of repolarization to the start of ventricular diastole by 39% at 10min in addition to the changes induced by the middle dose. No significant change was detected in a ventricular repolarization period. These results indicate that ONO-AE1-329 may possess a similar cardiovascular profile to typical phosphodiesterase 3 inhibitors as an inodilator, and suggest that EP4 receptor stimulation can become an alternative strategy for the treatment of congestive heart failure.

Influences of pyrexia and age on theophylline clearance in young children with asthma.

Fifty hospitalized children with asthmatic bronchitis and bronchial asthma were treated with a continuous intravenous drip infusion of aminophylline. To investigate the pharmacokinetics of theophylline in the presence of pyrexia, patients were divided into two groups based on body temperature: a pyrexia group (> or = 38 degrees C) and a non-pyrexia group (< 38 degrees C). Theophylline clearance was 0.064 +/- 0.017 liters/kg/hr in the non-pyrexia group and 0.049 +/- 0.010 liters/kg/hr in the pyrexia group. Theophylline clearance in the non-pyrexia and pyrexia groups was 0.044 +/- 0.007 liters/kg/hr and 0.030 +/- 0.009 liters/kg/hr (< or = 6 months), 0.071 +/- 0.011 liters/kg/hr and 0.047 +/- 0.008 liters/kg/hr (6 to < or = 12 months), 0.084 +/- 0.012 liters/kg/hr and 0.055 +/- 0.006 liters/ kg/hr (1 to < or = 2 years), and 0.065 +/- 0.007 liters/kg/hr and 0.051 +/- 0.001 liters/kg/hr (2 to < or = 3 years), respectively. In all age groups, theophylline clearance of the pyrexia group was significantly less than that of the non-pyrexia group (p < 0.01), showing that there was a significant pharmacokinetic difference in theophylline clearance between the groups. Multivariate statistical analysis showed that theophylline clearance was affected by pyrexia and age. This study showed that the presence of pyrexia decreases theophylline clearance, and that it affects theophylline clearance in an age-dependent manner. Based on the results of this study, dosages should be designed based on the clearance at the time of pyrexia.

[Endovascular treatment of a ruptured aneurysm associated with unilateral moyamoya disease].

We report a case presenting with subarachnoid hemorrhage due to a ruptured aneurysm associated with unilateral moyamoya disease. The patient was a 29-year-old woman exhibiting sudden onset headache. Computed tomography revealed subarachnoid hemorrhage around the brain stem. Cerebral angiography showed a saccular aneurysm at the junction of the left P1 portion of the posterior cerebral artery and its perforator. The right internal carotid artery was occluded at the terminal portion, and the right middle cerebral artery territory was perfused anterogradely via abnormal moyamoya vessels in the basal ganglia. The aneurysm was completely embolized with preservation of the perforator. We suggest that as compared to surgical clipping by craniotomy, endovascular therapy is safe and effective for treatment of intracranial aneurysms associated with moyamoya disease.

Long-term social isolation enhances picrotoxin seizure susceptibility in mice: up-regulatory role of endogenous brain allopregnanolone in GABAergic systems.

Allopregnanolone (ALLO, 3alpha,5alpha-tetrahydroprogesterone), a positive allosteric modulator of actions of gamma-aminobutyric acid GABA) at GABA(A) receptors, is synthesized in the brain from progesterone by the sequential action of two enzymes: a type I 5alpha-reductase and a 3alpha-hydroxysteroid oxidoreductase. We previously demonstrated that long-term social isolation of mice caused a significant decrease in brain ALLO content via suppression of type I 5alpha-reductase and its mRNA expression. In this study, to clarify a physiological role of endogenous brain ALLO, we investigated changes in seizure susceptibility of mice following protracted social isolation and compared with those of mice treated with SKF105111 (SKF), an inhibitor of types I and II 5alpha-reductase. Social isolation of mice for 7 weeks prior to the experiments caused a significant increase of seizure susceptibility to the GABA(A) receptor antagonist picrotoxin but not to the glycine receptor antagonist strychnine or the glutamate receptor agonist kainic acid. The change in the seizure susceptibility was completely reversed by 2.5 mg/kg ip ALLO, a dose that per se had no effect on picrotoxin-induced seizure. Treatment of mice with SKF (20 mg/kg ip) also reduced a threshold dose of picrotoxin, but not that of strychnine or kainic acid, which was required to elicit seizure in group-housed mice. The effect of SKF was attenuated by ALLO (2.5 mg/kg ip). In contrast, SKF treatment had no effect on picrotoxin-induced seizure in socially isolated mice. These findings suggest that endogenous brain ALLO plays a suppressive role in seizure susceptibility via a positive modulation of GABA(A) receptor function and that social isolation enhances seizure susceptibility in mice via reduction of GABA(A) receptor function caused by a decrease of endogenous ALLO.

Multiple intracranial seeding of craniopharyngioma after repeated surgery--case report.

A 17-year-old woman presented with a rare case of intracranial seeding of craniopharyngioma after repeated surgery. She initially presented with secondary amenorrhea and visual impairment. Magnetic resonance imaging revealed a suprasellar mass. Subtotal removal of the tumor was performed. The diagnosis was adamantinomatous craniopharyngioma. Seven months later, the patient underwent a second operation for recurrence of the craniopharyngioma. Subsequently, ventriculoperitoneal (VP) shunting and gamma knife surgery were performed. Twenty-seven months after the first operation, multiple cystic lesions were found in the right frontal and temporal lobes. Positive tumor cytology was observed in the cerebrospinal fluid obtained from the VP shunt chamber. These tumors were subtotally resected. However, the patient died from consecutive tumor recurrence 4 years after the initial diagnosis.