Double-access-port endotracheal tube for selective lung ventilation in pediatric patients.
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Bronchoscopes↗
Biomedical subjects
T Horinouchi
Publications and source records attributed to T Horinouchi.
Partial agonistic effects of carteolol on atypical beta-adrenoceptors in the guinea pig gastric fundus.
The properties of the beta1-/beta2-adrenoceptor partial agonist carteolol were investigated in atypical beta-adrenoceptors on the guinea pig gastric fundus. Carteolol induced concentration-dependent relaxation in this tissue (pD2 = 5.55, intrinsic activity = 0.94). However, a combination of the selective beta1-adrenoceptor antagonist atenolol (100 microM) and the selective beta2-adrenoceptor antagonist butoxamine (100 microM) produced only small rightward shifts in the concentration-response curves of carteolol in the gastric fundus (pD2 = 4.91, intrinsic activity = 0.94). In the presence of both atenolol (100 microM) and butoxamine (100 microM), the non-selective beta1-, beta2- and beta3-adrenoceptor antagonist (+/-)-bupranolol (10-100 microM) caused a concentration-dependent right-ward shift of the concentration-response curves for carteolol in the guinea pig gastric fundus. Schild plot analyses of the effects of (+/-)-bupranolol against carteolol gave the pA2 value of 5.29 and the Schild slope was not significantly different from unity. Furthermore, carteolol (10 microM) weakly but significantly antagonized the relaxant responses to catecholamines ((-)-isoprenaline, (-)-noradrenaline and (-)-adrenaline), a selective beta3-adrenoceptor agonist BRL37344 ((R*,R*)-(+/-)-4-[2-[(2-(3-chlorophenyl)-2-hydroxyethyl)amino]propyl]phenoxy-acetic acid sodium salt) and a non-conventional partial beta3-adrenoceptor agonist (+/-)-CGP12177A ([4-[3-[(1,1dimethylethyl)amino]-2-hydroxypropoxy]-1,3-dihydro-2H-benzimidazol-2-one] hydrochloride) in the guinea pig gastric fundus. These results suggest that the partial agonistic effects of carteolol are mediated by atypical beta-adrenoceptors in the guinea pig gastric fundus.
Adrenergic beta-Agonists↗
Further evidence that (+/-)-carteolol-induced relaxation is mediated by beta2-adrenoceptors but not by beta3-adrenoceptors in the guinea pig taenia caecum.
The properties of the beta1- and beta2-adrenoceptor partial agonist (+/-)-carteolol were investigated against the beta2- and beta3-adrenoceptors of the taenia caecum of the guinea pig. (--)-Isoprenaline and (+/-)-carteolol induced concentration-dependent relaxation in this tissue. The non-selective beta1- and beta2-adrenoceptor antagonist (+/-)-propranolol (10-100 nM), the selective beta2-adrenoceptor antagonist ICI 118,551 (10-100 nM) and the non-selective beta1-, beta2- and beta3-adrenoceptor antagonist (+/-)-bupranolol (10-100nM), caused a concentration-dependent rightward shift of the concentration-response curves for (--)-isoprenaline and (+/-)-carteolol. Schild regression plot analyses carried out for (+/-)-propranolol against (--)-isoprenaline and (+/-)-carteolol gave pA2 values of 8.35 and 8.24, respectively. Schild plot analyses of ICI 118,551 against (--)-isoprenaline and (+/-)-carteolol gave pA2 values of 8.47 and 8.41, respectively. Schild plot analyses of (+/-)-bupranolol against (--)-isoprenaline and (+/-)-carteolol gave pA2 values of 8.47 and 8.53, respectively. Slopes of the Schild plots were not significantly different from unity. These results suggest that the relaxant effects of (+/-)-carteolol in the guinea pig taenia caecum are mediated by beta2-adrenoceptors but not by beta3-adrenoceptors.
Adrenergic beta-2 Receptor Antagonists↗
The beta3-adrenoceptor-mediated relaxation induced by epinephrine in guinea pig taenia caecum.
The mechanisms of the beta-adrenoceptor mediated relaxation induced by epinephrine in guinea pig taenia caecum were examined. The relaxant response to epinephrine was unaffected by propranolol (approximately 10(-5) M) or phentolamine (approximately 10(-5) M). The response to epinephrine was antagonized in a concentration dependent manner by bupranolol, and Schild plot of the data revealed the pA2 value of 5.87. Epinephrine significantly increased cyclic AMP level in this preparation. Bupranolol (10(-4) M) significantly decreased the cyclic AMP level that was elicited by epinephrine, whereas propranolol (10(-5) M) produced no effect. These results suggest that the relaxant response to epinephrine in the guinea pig taenai caecum is mainly mediated by beta3-adrenoceptors.
Animals↗
Characterization of atypical beta-adrenoceptors in the guinea pig duodenum.
The atypical beta-adrenoceptors mediating relaxation in the guinea pig duodenum were studied using catecholamines (isoprenaline, noradrenaline and adrenaline), a selective beta3-adrenoceptor agonist BRL37344 ((R*,R*)-(+/-)-4-[2-[(2-(3-chlorophenyl)-2-hydroxyethyl)amino]propyl]phe noxyacetic acid sodium salt) and a non-conventional partial beta3-adrenoceptor agonist CGP12177A ((-)-4-(3-t-butylamino-2-hydroxypropoxy)benzimidazol-2-one)). Catecholamines and beta3-adrenoceptor agonists induced concentration-dependent relaxation in this preparation. Propranolol (1 microM) produced only small rightward shifts in the concentration-response curves of these agonists. In the presence of propranolol (1 microM), however, a non-selective beta1-, beta2- and beta3-adrenoceptor antagonist bupranolol caused a concentration-dependent rightward shift of the concentration-response curves for catecholamines and beta3-adrenoceptor agonists. Schild plot analyses of the effects of bupranolol against these agonists gave pA2 values of 6.02 (isoprenaline), 5.98 (noradrenaline), 5.93 (adrenaline), 6.51 (BRL37344) and 5.70 (CGP12177A), respectively, and all Schild slopes were not significantly different from unity. These results suggest that atypical beta-adrenoceptors are present in the guinea pig duodenum and involved in mediating the functional relaxant response.
Adrenergic beta-Agonists↗
Effect of bupranolol for BRL37344 and noradrenaline-induced relaxations mediating atypical beta/beta3-adrenoceptor in rat oesophageal muscularis mucosae.
We previously suggested that the existence of atypical beta/beta3-adrenoceptor with pA2-values for bupranolol, a non-selective beta-adrenoceptor antagonist, against BRL37344 and noradrenaline were 5.79 and 5.53 in guinea pig taenia caecum, respectively. We furthermore determined the affinity of bupranolol to subclassify atypical beta/beta3-adrenoceptor in rat oesophageal muscularis mucosae, because it is rich in atypical beta/beta3-adrenoceptor. BRL37344 and noradrenaline produced a concentration-dependent relaxation of rat oesophageal muscularis mucosae. The responses to BRL37344 and noradrenaline were resistant to 3x10(-6) M propranolol, 10(-4) M atenolol, and 10(-4) M butoxamine. However, bupranolol antagonized the responses to BRL37344 and noradrenaline in a concentration-dependent manner. Schild plot analyses of bupranolol against BRL37344 and noradrenaline gave pA2-values of 7.06 and 6.96, respectively. These results suggest that bupranolol can distinguish the difference in affinity between atypical beta/beta3-adrenoceptors in rat oesophageal muscularis mucosae and guinea pig taenia caecum. The difference in behavior of bupranolol confirms the existence of some atypical beta/beta3-adrenoceptors subtypes.
Adrenergic alpha-Agonists↗
Pharmacological analysis of atypical beta-adrenoceptors in the guinea pig gastric fundus using the beta(3)-adrenoceptor antagonist bupranolol.
Atypical beta-adrenoceptor-mediated relaxations to catecholamines (isoprenaline, noradrenaline and adrenaline) and beta(3)-adrenoceptor agonists, BRL37344 [(R*, R*)-(+/-)-4-[2-[(2-(3-chlorophenyl)-2-hydroxyethyl)amino]-propyl]phen oxyacetic acid sodium salt] and CGP12177A [(-)-4-(3-t-butylamino-2-hydroxy- propoxy)benzimidazol-2-one] in guinea pig gastric fundus were investigated. The five agonists induced concentration-dependent relaxation of the gastric fundus. In the presence of both atenolol and butoxamine only small rightward shifts of the concentration-response curves to these agonists were observed. Under this condition, however, bupranolol caused a concentration-dependent rightward shift of the concentration-response curve to catecholamines and beta(3)-adrenoceptor agonists. Schild plot analyses of bupranolol against these agonists gave pA(2) values of 6.08 (isoprenaline), 6. 04 (noradrenaline), 5.90 (adrenaline), 6.50 (BRL37344) and 5.80 (CGP12177A), respectively. These results clearly suggest that the existence of functional atypical beta-adrenoceptors in the guinea pig gastric fundus and the relaxation of these agonists in this tissue are mediated via atypical beta-adrenoceptors.
Adrenergic beta-Agonists↗
[Pharmacological analysis of atypical beta-adrenoceptors in the guinea pig gastrointestinal tissue systems].
The purpose of the present study was to characterize the atypical beta-adrenoceptors involved in relaxant responses in guinea pig gastric fundus, duodenum and ileum in functional experiments with catecholamines (isoprenaline, noradrenaline and adrenaline), beta 3-adrenoceptor agonists (BRL37344 and CGP12177A) and a non-selective beta 1-, beta 2- and beta 3-adrenoceptor antagonist bupranolol, and to obtain further evidence to clarify whether there is a tissue difference in atypical beta-adrenoceptors in the guinea pig gastrointestinal tissue systems. The atypical beta-adrenoceptors are present in gastric fundus, duodenum and ileum of guinea pig. In the presence of propranolol (1 microM) or atenolol (100 microM) plus butoxamine (100 microM), bupranolol caused a concentration-dependent rightward shift of the concentration-response curves for catecholamines and beta 3-adrenoceptor agonists. There was not a significant difference of pA2 values for bupranolol against these agonists between gastric fundus, duodenum and ileum of guinea pig. These results suggest that guinea pig gastric fundus, duodenum and ileum relaxation are mediated predominantly by an atypical beta-adrenoceptor population whereas the classical beta 1- or/and beta 2-adrenoceptors play a subordinate function role and that the receptors of three tissues are pharmacological identified by functional approaches. There is not a tissue difference in atypical beta-adrenoceptors in the guinea pig gastrointestinal tissue systems between stomach and ileum.
Adrenergic beta-Agonists↗
[Unruptured aneurysm of the right sinus of Valsalva: a case report].
A previously healthy and asymptomatic 45-year-old woman was referred for evaluation of a heart murmur and an unusual dilatation in the aortic root. Transthoracic and transesophageal echocardiography, computed tomography, magnetic resonance imaging, and cardiac catheterization revealed an aneurysm with a maximum diameter of 6.0 cm in the right sinus of Valsalva. Aortic regurgitation and stenosis at the right ventricle outflow tract were associated with the aneurysm. Surgery and histological study demonstrated that the sinus of Valsalva aneurysm was enormously dilated with idiopathic degenerative change in the aortic media. The aneurysm was tremendously large compared to any previously reported. Decrease in pressure load during diastole caused by aortic regurgitation probably resulted in the growth of this huge aneurysm without rupture.
Aortic Aneurysm↗
[Evaluation of left ventricular diastolic function during coronary artery bypass grafting by color M-mode Doppler echocardiography].
The objective of the present study was to evaluate the effects of the coronary artery bypass graft surgery (CABG) and cardioplegic arrest on left ventricular diastolic function. Ten patients with coronary artery disease were studied by transesophageal Doppler echocardiography. Doppler measurements included peak velocity during early filling (peak E velocity), peak velocity during atrial contraction (peak A velocity), and the ratio of peak E velocity to peak A velocity (E/A). The rate of propagation of peak early filling flow velocity (FPV) was also measured using color M-mode Doppler echocardiography. Hemodynamic and Doppler-derived variables were measured before and after sternotomy, after the end of cardiopulmonary bypass (CPB) and after closure of the sternum. E/A showed a significant decrease after sternotomy and did not return to the pre CPB level. FPV increased after CPB. FPV was correlated with E/A (r = 0.54, P = 0.013 pre-CPB; r = 0.54, P = 0.014 post-CPB). E/A showed a significant correlation with heart rate. After the influence of heart rate had been eliminated by the analysis of covariance, corrected E/A value showed a significant increase post-CPB compared to that in pre-CPB (0.68 +/- 0.29 to 1.10 +/- 0.29, P < 0.05). In conclusion, FPV and heart-rate-corrected E/A increased after CPB. This suggests improvement of diastolic function during CABG.
Aged↗
The beta2- and beta3-adrenoceptor-mediated relaxation induced by isoprenaline and salbutamol in guinea pig taenia caecum.
To understand the receptor subtypes responsible for beta-adrenoceptor-mediated relaxation of guinea pig taenia caecum, we investigated the effects of isoprenaline and salbutamol. Isoprenaline and salbutamol caused dose-dependent relaxation of the guinea pig taenia caecum. Propranolol, bupranolol and butoxamine produced shifts of the concentration response curves for isoprenaline and salbutamol. Schild regression analyses carried out for propranolol against isoprenaline and salbutamol gave pA2 values of 8.43 and 8.88, respectively. Schild regression analyses carried out for butoxamine against isoprenaline and salbutamol gave pA2 values of 6.46 and 6.68, respectively. Schild regression analyses carried out for bupranolol against isoprenaline and salbutamol gave pA2 values of 8.60 and 8.69, respectively. However, in the presence of 3 x 10(-4) M atenolol, 10(-4) M butoxamine and 10(-6) M phentolamine to block the beta1-, beta2- and alpha-adrenoceptor effects, respectively, Schild regression analyses carried out for bupranolol against isoprenaline and salbutamol gave pA2 values of 5.77 and 5.97, respectively. These results suggest that the relaxant responses to isoprenaline and salbutamol in the guinea pig taenia caecum are mediated by both the beta2- and the beta3-adrenoceptors.
Adrenergic beta-2 Receptor Agonists↗
An evaluation of neuromuscular reversal with edrophonium in a patient with malathion intoxication.
We evaluated the neuromuscular reversal with edrophonium using peripheral nerve stimulator and recorder in a patient with malathion intoxication. Edrophonium 10 mg i.v. caused an increase in single twitch tension by 76% of the control during the recovery phase from an acute cholinergic crisis 16 days after ingestion of malathion solution. The present study indicated that edrophonium test seems to be a reliable monitoring in evaluating neuromuscular reversal in the patient with acute malathion insecticide poisoning.
Adult↗
[Assessment of left ventricular contractility during intravenous induction of anesthesia by echocardiographic automated border detection].
A recently developed echocardiographic imaging system provides real-time automated border detection (ABD), which enables the measurement of cyclic changes in cavity area, and thus the calculation of changes in intracavity volumes. Eight patients (ASA 1-2) for non-cardiac surgery received thiopental (6 mg.kg-1) and succinylcholine (1 mg.kg-1) intravenously, and the trachea was intubated. The transthoracic echocardiography (TTE) was performed before induction. after induction, and after orotracheal intubation. Left ventricular end-diastolic volume (EDV), end-systolic volume (ESV), stroke volume (SV) and ejection fraction (EF) were measured with ABD in apical four-chamber view. Mean arterial pressure (MAP) was measured simultaneously. MAP/ESV and MAP/SV were calculated as parameters of left ventricular contractility and left ventricular afterload, respectively. EF decreased significantly (P < 0.05) after induction (50.3 +/- 8.6%) compared with the value before induction (57.9 +/- 8.7%), and decreased further after intubation (41.7 +/- 10.6%). MAP/ESV also decreased significantly (P < 0.05) after induction (2.75 +/- 1.12 mmHg.ml-1) compared with the pre-induction value (3.81 +/- 1.73 mmHg.ml-1), and then returned to the pre-induction level after intubation (3.25 +/- 1.22 mmHg.ml-1). MAP/ SV showed no significant change during induction, and increased significantly (P < 0.05) after intubation (4.60 +/- 1.66 mmHg.ml-1) compared with pre-induction value (2.60 +/- 0.46 mmHg.ml-1). These findings suggest that the significant reduction in EF after induction of anesthesia was due to depression of cardiac contractility by thiopental, and that the further decrease after intubation was due to increase in afterload caused by the stimuli during intubation.
Adolescent↗
Possible mechanisms of beta-adrenoceptor-mediated relaxation induced by noradrenaline in guinea pig taenia caecum.
The mechanisms of the beta-adrenoceptor-mediated relaxation induced by noradrenaline in guinea pig taenia caecum were investigated. Noradrenaline caused graded relaxation of this preparation. However, the concentration-response curves for noradrenaline were unaffected by propranolol (approximately 10(-5) M) or phentolamine (approximately 10(-5) M). The responses to noradrenaline were antagonized in a concentration-dependent manner by bupranolol, and Schild plots of the data revealed a pA2 value of 5.53. Also, bupranolol antagonized responses to isoprenaline, and Schild plots of the data revealed the pA2 value to be 8.53. Noradrenaline significantly increased the cyclic AMP level in this preparation. Bupranolol (10(-4) M) significantly decreased the cyclic AMP response elicited by noradrenaline, whereas propranolol (10(-5) M) produced no effect. These results suggest that the relaxant response to noradrenaline in guinea pig taenia caecum is mainly mediated by beta 3-adrenoceptors (or atypical beta-adrenoceptors) and that in guinea pig taenia caecum noradrenaline behaves as a beta 3-selective adrenoceptor agonist.
Adrenergic beta-Agonists↗
Effect of bupranolol on CGP 12177-induced relaxation and cAMP accumulation in the guinea pig taenia caecum.
1. The effect of bupranolol on CGP 12177-induced relaxation and cAMP accumulation in the guinea pig taenia caecum was examined. 2. The relaxant response to CGP 12177 was unaffected by propranolol (approximately 10(-6) M), whereas that to CGP 12177 was antagonized in a concentration-dependent manner by bupranolol; Schild plot of the data revealed the pA2 value of 5.61. 3. CGP 12177 significantly increased cyclic AMP level in this preparation. Bupranolol (10(-4) M) significantly decreased the cyclic AMP level that was elicited by CGP 12177, whereas propranolol (10(-5) M) produced no effect. 4. These results suggest that bupranolol appears to be an efficient beta3-antagonist in the guinea pig taenia caecum and confirm that the response to CGP 12177 is mediated by beta3-adrenoceptors.
Adrenergic beta-Antagonists↗
Signal transduction pathway involved in beta 3-adrenoceptor-mediated relaxation in guinea pig taenia caecum.
Experiments were carried out to examine the components of the intracellular second messenger system that is involved in beta 3-adrenoceptor (atypical beta-adrenoceptors)-mediated relaxation in the guinea pig taenia caecum. Propranolol and butoxamine caused competitive antagonism of the relaxant response to isoprenaline. However, propranolol or butoxamine did not significantly affect the relaxant responses to CGP 12177 (4-[3-[(1,1-dimethylethyl)amino]-2-hydroxypropoxy]-1,3-dihydro-2H- benzimidazol-2-one), a beta 3-adrenoceptor agonist. The concentration-response curves of the isoprenaline-induced increase in adenosine 3',5'-cyclic monophosphate (cyclic AMP) levels were shifted to the right in a parallel manner by propranolol and butoxamine. However, propranolol or butoxamine did not significantly affect the concentration-response curve for the CGP 12177-induced increase in cyclic AMP levels. MDL 12330 (cis-N-(2-phenylcyclopentyl)-azacyclotridec-1-en-2-amine) inhibited the isoprenaline- or CGP 12177-induced increase in cyclic AMP levels. These results suggest that the production of cyclic AMP contributes to the beta 3-adrenoceptor (or atypical beta-adrenoceptor)-mediated relaxation of the guinea pig taenia caecum.
Adenylyl Cyclases↗
Comparison of interactions of R(+)- and S(-)-isomers of beta-adrenergic partial agonists, befunolol and carteolol, with high affinity site of beta-adrenoceptors in the microsomal fractions from guinea-pig ciliary body, right atria and trachea.
1. The stereoselectivities of beta-adrenergic partial agonists for the high affinity binding site of beta-adrenoceptors in the guinea-pig ciliary body, right atria and trachea were studied. 2. The inhibition curves by the S(-)-isomers of befunolol and carteolol were not significantly different from that by the R(+)-isomers in the guinea-pig ciliary body. 3. The inhibition curves by the S(-)-isomers of befunolol and carteolol were about 10 times as potent as the R(+)-isomers in the guinea-pig atria and trachea. 4. The pKi values of the S(-)-isomers of befunolol and carteolol were significantly larger than those of R(+)-isomers in the guinea-pig atria and trachea but not larger than those of the R(+)-isomers in the guinea-pig ciliary body. 5. These results suggest that the high affinity binding site of beta-adrenoceptors in ciliary body cannot discriminate stereoselectively between the R(+)- and S(-)-isomers, while in other tissues there is stereoselectivity between the two enantiomers.
Adrenergic beta-Agonists↗
Involvement of beta 3-adrenoceptor in the relaxation response in guinea pig taenia caecum.
beta-Adrenoceptors in the guinea pig taenia caecum were investigated by measuring relaxation responses to agonists and by a radioligand binding assay using [3H]CGP 12177. The rightward shift of the isoprenaline concentration-response curve was observed by butoxamine, a beta 2-selective antagonist, and the pA2 value for butoxamine was 6.46. In control preparations, catecholamines caused relaxation with the following rank order of potency: isoprenaline > adrenaline > noradrenaline. However, in the presence of 10(-6) M phentolamine, 3 x 10(-4) M atenolol and 10(-4) M butoxamine, the rank order of potency of the agonists was: isoprenaline > noradrenaline > adrenaline. CGP 12177 caused graded relaxation of the guinea pig taenia caecum, and this response was not influenced by 10(-6) M phentolamine, 3 x 10(-4) M atenolol, 10(-4) M butoxamine or 10(-6) M propranolol. The Scatchard plot of the specific [3H]CGP 12177 binding to microsomal fractions from the guinea pig taenia caecum showed two affinity sites of the receptor: high affinity (KD = 0.64 nM) and low affinity (KD = 142.21 nM) sites. The pKD value of the high affinity site of [3H]CGP 12177 was in agreement with its pA2 value, and that of the low affinity site was in agreement with its pD2 value. These results suggest that isoprenaline-, noradrenaline- and adrenaline-induced relaxations of the guinea pig taenia caecum predominantly involve beta 2- and beta 3-adrenoceptors, whereas CGP 12177-induced relaxation is mediated solely through beta 3-adrenoceptors.
Adrenergic beta-Antagonists↗