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Medical research on betoptic
Atrium contributes to osmoregulation in eels acclimated to sea water.
Zoolog Sci. 2000 Apr 1; 17(3): 301-6
Ando M, Sakaguchi K, Yasuda M, Uesaka T, Kim HT, Kawahara A
Since highly concentrated NaCl is suspected to enter into the heart of the seawater eels, effects of high NaCl concentration on the atrial beating was examined, and plasma ion concentrations and osmolality were measured simultaneously in the blood collected from the bulbus arteriosus and from the caudal vessels. When 100 mmole l(-1) NaCl was added to the incubation medium, atrial contraction was enhanced significantly. Similar enhancement in the atrial contractility was also observed after addition of NaCH3SO4 (100 mmole l(-1)) or Tris HCl (100 mmole l(-1)), indicating that Na(+) and Cl(-) are not indispensable for the positive inotropic effect. Furthermore, an addition of sucrose (200 mmole l(-1)) also enhanced the contraction. Inversely, hypoosmotic solution reduced the atrial contraction. These results indicate that the eel atrium is sensitive to environmental osmolarity. The eel atrium responses even at 20 mmole l(-1) sucrose. Such an inotropic effect of sucrose was not depressed after blocking adrenoceptor with betaxolol, a beta1-adrenoceptor antagonist, indicating that the effect is not due to adrenaline release from nerve endings. Plasma osmolality and Na(+) concentration were higher in bulbus arteriosus than in caudal vessels, indicating that the eel heart is really exposed to hyperosmotic blood in sea water. The osmotically enhanced atrial contraction may increase the cardiac outflow into the gill. Such property of the atrium would have clear advantages for seawater teleosts, since the concentrated NaCl from the esophagus can be excreted immediately through the gill, without circulating their body, and blood homeostasis can be maintained efficiently.
Circ J. 2008 May; 72(5): 764-9
Takase B, Takeishi Y, Hirai T, Lee JD, Uzui H, Senda S, Miwa K, Hiraoka Y, Kinugawa T, Hosokawa R, Fujita M
Background The aim of the study was to evaluate whether the combined treatment of calcium channel blocker, amlodipine and beta-blocker, betaxolol, favorably affects cardiac autonomic nervous activity (CANA) and health-related quality of life (HRQL). Methods and Results A total of 65 patients with a poor blood pressure (BP) control with a low dose amlodipine therapy were randomly assigned to the amlodipine dose-up group (n=21) and betaxolol adding group (n=44). Before and after a 6-month treatment, BP, heart rate variability (HRV), HRQL and blood chemistries were evaluated. Low frequency (LF) spectra/high frequency (HF) spectra and HF/total power spectra (TP) were calculated as indexes of CANA, and HRQL was assessed by the questionnaire sheets. BP was well controlled in all patients of the present study. In the betaxolol adding group, LF/HF decreased (2.1+/-1.9 to 1.3+/-0.9, p
[Genetic aspects of individual sensitivity to betaxolol in patients with arterial hypertension]
Kardiologiia. 2008; 48(3): 20-6
Minushkina LO, Zateishchikova AA, Zateishchikov DA, Mankhaeva BB, Savel'eva EG, Kochkina MS, Brovkin AV, Nikitin AG, Nosikov VV, Sidorenko BA
Association of polymorphism of b1-adrenoreceptors gene and cytochrome 2D6 gene with efficacy of b-adrenoblocker betaxolol was studied in 81 patients with I and II degree arterial hypertension. Betaxolol (10-20 mg/day) was given for 4 weeks, its efficacy was assessed by office blood pressure (BP) measurements, 24-hour BP and ECG monitoring and standard exercise test. At the end of the study significant lowering of systolic and diastolic BP was noted by 11,8 +/- 2,47 (p=0,001) and 7,8 +/- 1,68 mm Hg (p=0,001), respectively. Heart rate (HR) at rest lowered by 19,8 +/- 1,96 beats/min (p=0,0001). At analysis of individual reaction of patients to treatment with betaxolol it turned out that decrease of BP and HR was variable, but their distribution in the group did not differ significantly from normal. Hypotensive activity and influence on HR were confirmed by results of all instrumental investigations. No significant differences were revealed in dynamics of systolic and diastolic BP both at rest and at effort between patients with different genotypes of polymorphic marker Gly389Arg of ADRB1 gene. Compared with carriers of genotype Ser/Ser carriers of genotype Ser/Pro of polymorphic marker Pro34Ser of Cyp2D6 gene had significantly more pronounced decrease of HR at the background of treatment with betaxolol: - 32,6 +/- 4,77 and - 18,4 +/- 2,01 beats/min (p=0,023) at rest and - 30,1 +/- 3,05 and - 24,0 +/- 2,59 beats/min (p=0,043) at maximal exercise, respectively. These patients had also more pronounced lowering of diastolic BP at maximal work load and more pronounced increase of exercise duration at the background of treatment. Thus efficacy of betaxolol in patients with hypertension was associated solely with genotype of polymorphic marker Ser34Pro of CYP2D6 gene. In patients having in genotype Pro allele of polymorphic marker Pro34Ser of CYP2D6 gene therapy with betaxolol is more effective, than in homozygote carriers of Ser allele. This can be related to low rate of metabolism of the preparation in these patients.
Pol Arch Med Wewn. 2008 Jan-Feb; 118(1-2): 36-41
Małyszko J, Tymcio J
INTRODUCTION: Hypertension is associated with hemostatic abnormalities and endothelial dysfunction. thrombin activatable fibrinolysis inhibitor (TAFI) is a glycoprotein linking coagulation and fibrinolysis. Objectives. We evaluated TAFI concentrations in patients with essential hypertension in relation to blood pressure. Additionally, we studied TAFI activator, thrombin activity (thrombin-antithrombin complexes--TAT, prothrombin fragments F1 + 2), thrombomodulin (TM)--a marker of endothelial cell injury, degree of plasmin generation (plasmin-antiplasmin complexes [PAP]), other markers of endothelial cell injury--von Willebrand factor (vWF). PATIENTS AND METHODS: Seventy-two patients with essential hypertension (27 untreated, 13 treated with enalapril (angiotensin-converting enzyme inhibitor [ACEI]), 32 with beta-blocker, betaxolol). In every hypertensive patients ambulatory blood pressure measurements and echocardiography were performed. RESULTS: All hypertensive patients did not differ with respect to age, creatinine, fibrinogen, D-dimers. In ACEI-treated patients a significantly higher TAFI concentration was observed when compared to beta-blocker-treated patients. In beta-blocker-treated patients both diastolic and systolic blood pressure were lower than in ACEI treated patients as well as ejection fraction, while serum triglycerides were higher. Diastolic blood pressure correlated significantly with TAFI concentrations in untreated patients (r = 0.27, p < 0.05), and in beta-blocker-treated patients (r = 0.25, p = 0.05), TAFI activity was inversely associated with interventricular septal diameter (r = -0.75, p < 0.01) in patients treated with ACEI. CONCLUSIONS: Elevated TAFI concentrations and enhanced thrombin generation in hypertensive patients may contribute to atherosclerosis progression in this population. Differences in the studied parameters may be due to a small sample size, monotherapy and potential effects of antihypertensive drugs on glicemia, ejection fraction and triglycerides.
beta1- and beta2-adrenoceptor induced synaptic facilitation in rat basolateral amygdala.
Brain Res. 2008 May 13; 1209: 65-73
Abraham PA, Xing G, Zhang L, Yu EZ, Post R, Gamble EH, Li H
The expression and characteristics of beta-adrenoceptor subtypes (beta1 and beta2) and their agonist actions on synaptic transmission in the basolateral amygdala (BLA) of the rat were examined using in situ hybridization, quantitative real-time PCR, Western blot analysis and field potential recording. In situ hybridization data revealed an intense distribution of beta1-and beta2-adrenoceptor mRNA in the BLA. Real-time PCR analysis of rat amygdala revealed significant transcriptional expression levels of both beta-adrenoceptors, with beta2-adrenoceptors outnumbering beta1-adrenoceptors in a ratio of 2.9 to 1. Bath application of the selective beta1-adrenoceptor agonist xamoterol hemifumarate (10 microM) facilitated the excitatory field synaptic potential evoked in the BLA by stimulation of the external capsule by 186.5+/-10.7% of control amplitude. In the presence of the selective beta1-adrenoceptor antagonist betaxolol hydrochloride (30 microM), the facilitating effects of field excitatory synaptic potential induced by the agonist were reduced to 126.1+/-2.3 % of control amplitude in the BLA. Bath application of the selective beta2-adrenoceptor agonist salmeterol (15 microM) facilitated the excitatory field synaptic potential evoked in the BLA by stimulation of the external capsule by 167.3+/-9.7 % of control amplitude. In the presence of the selective beta2-adrenoceptor antagonist ICI 118,551 HCl (30 microM), the facilitating effects of field excitatory synaptic potential induced by the agonist were reduced to 121.1+/-4.1 % of control amplitude in the BLA. These data suggest that beta-adrenoceptor mediated synaptic facilitation in the amygdala is mediated by both beta1 and beta2-adrenoceptor activation.
J Ocul Pharmacol Ther. 2008 Apr; 24(2): 230-4
Ikeda Y, Mori K, Ishibashi T, Naruse S, Nakajima N, Kinoshita S
AIMS: The effects of switching from topical beta-blockers (beta) to latanoprost (LA) on intraocular pressure (IOP) and IOP-reduction rate (IOP-RR) in patients with normal-tension glaucoma (NTG) were investigated. SUBJECTS AND METHODS: Sixty (60) NTG patients (60 eyes) were divided into three equal groups receiving carteolol hydrochloride (group A), nipradilol (group B), and betaxolol hydrochloride (group C) twice-daily for 3 months. The drugs were changed to topical LA administered once-daily for the next 3 months. RESULTS: Baseline IOP was 14.4 +/- 0.9, 14.6 +/- 0.6, and 14.6 +/- 0.9 mmHg in groups A, B, and C, respectively. At 3 months, IOP was 12.4 +/- 0.6, 13.4 +/- 0.6, and 12.9 +/- 0.8 mmHg and 10.5 +/- 0.5, 11.1 +/- 0.8, and 11.7 +/- 0.8 mmHg at 6 months in groups A, B, and C, respectively. At 3 months, IOP-RR was 10.4 +/- 5.5, 9.5 +/- 2.6, and 10.8 +/- 4.7% and 24.1 +/- 4.3, 22.9 +/- 5.9, and 19.4 +/- 3.8% at 6 months in groups A, B, and C, respectively. The groups did not significantly differ in the first 3 months regarding IOP and IOP-RR. Switching to LA significantly decreased IOP and increased IOP-RR in all groups. CONCLUSION: In NTG patients, LA reduced IOP more effectively than the beta tested.
J Pharmacol Sci. 2008 Mar; 106(3): 423-34
Nagata T, Ueno S, Morita H, Kubota T, Toyohira Y, Tsutsui M, Tawara A, Yanagihara N
In the present study, we investigated the direct effects of antiglaucoma drugs (timolol, betaxolol, pilocarpine, and latanoprost) on N-methyl-D-aspartate (NMDA)-receptor function using a Xenopus oocytes expression system and electrophysiological techniques. In oocytes expressing wild-type NMDA (NR1a/NR2A) receptors, timolol and betaxolol significantly inhibited glutamate-evoked currents, whereas less inhibition was obtained with pilocarpine, and latanoprost had few effects. Moreover, the effect of timolol and betaxolol was noncompetitive with respect to glutamate. Mutations that changed Asn616 of the NR1a subunit, a critical residue for Mg(2+) blocking of NMDA receptors, to Arg (N616R) or Gln (N616Q) almost eliminated the inhibitory effects of timolol and betaxolol, as well as the blocking effect of Mg(2+). Experiments were also carried out to examine the protective effects of timolol and betaxolol against death of oocytes expressing NMDA receptors. During incubation of oocytes, especially in Mg(2+)-free medium, cell death was induced by addition of glutamate because of the continuous activation of the NMDA receptors expressed. Timolol and betaxolol significantly improved oocyte viability when they were added during the incubation period. These results suggest that timolol and betaxolol may have an additional role that they directly inhibit NMDA-receptor function, possibly via N616 of the NR1a subunit.
Cost analysis of glaucoma medications.
Am J Ophthalmol. 2008 Jan; 145(1): 106-13
Rylander NR, Vold SD
PURPOSE: To provide patients and health care providers with calculated yearly costs of topical glaucoma medications. DESIGN: Prospective, experimental, laboratory study. METHODS: Using the average wholesale price and common dosing patterns, we calculated the theoretical yearly cost of glaucoma medications. RESULTS: Calculated yearly cost ranged from $150.81 for generic timolol maleate 0.5% (Falcon Pharmaceuticals, Ltd, Fort Worth, Texas, USA) to $697.42 for Cosopt (Merck & Co, West Point, Pennsylvania, USA), and as high as $873.98 for a three-times-daily dose of Alphagan P 0.15% (Allergan, Inc, Irvine, California, USA). Among brand name beta-blockers, yearly cost ranged between $203.47 for Timoptic 0.5% (Merck & Co) and $657.24 for Betoptic S (Alcon Laboratories, Fort Worth, Texas, USA). Generic beta-blockers consistently were more economical than their brand-name counterparts. Yearly cost of prostaglandin analogs ranged from $427.69 for Travatan (Alcon) to $577.62 for Lumigan (Allergan). The two carbonic anhydrase inhibitors Azopt (Alcon) and Trusopt (Merck & Co), yielded similar economic profiles. Alphagan P 0.15% had yearly calculated costs of $559.08 for twice daily dosing per eye. The generic selective alpha(2)-agonist brimonidine tartrate 0.2% (Bausch & Lomb Pharmaceuticals, Tampa, Florida, USA) costs approximately $352.89 and $529.34 per year for the respective two and three drops daily per eye regimens. CONCLUSIONS: Nonselective beta-blockers remain the most inexpensive class of glaucoma medications. Bottle size may impact yearly glaucoma medication expenditures. Costs of glaucoma medications may impact decision making in the medical management of glaucoma.
Daily cost of glaucoma medications in China.
J Glaucoma. 2007 Oct-Nov; 16(7): 594-7
Gao Y, Wu L, Li A
PURPOSE: To determine and compare the daily cost of various glaucoma medications in China. MATERIALS AND METHODS: The majority of glaucoma medications commercially available in China were included in this research. The total number of drops in 1 bottle of each medication was counted drop by drop. The mean volume per bottle of each medication was calculated. The cost per drop, number of days for both eyes usage per bottle, and daily cost was calculated. RESULTS: (1) The volume per drop ranged from 0.03 mL (brinzolamide 1%, travoprost 0.004%, bimatoprost 0.03%, and latanoprost 0.005%) to 0.05 mL (timolol 0.5%-Chengrui and pilocarpine 0.5% and 2%-Zhenrui). (2) The cost per bottle ranged from $0.69 (US dollar) (timolol 0.5%-Malaisuan Saimaluo'er) to $40.78 (latanoprost 0.005%). (3) The number of days for both eyes usage per bottle ranged from 52 days (bimatoprost 0.03%) to 11 days (pilocarpine nitrate 0.5%-Zhenrui). (4) The daily cost for both eyes usage from expensive to cheap were latanoprost 0.005%-$0.91, travoprost 0.004%-$0.77, brimonidine 0.2%-$0.61, bimatoprost 0.03%-$0.46, D-timolol 1%-$0.36, brinzolamide 1%-$0.34, pilocarpine 2%-Zhenrui-$0.28, levobunolol 0.5%-$0.25, betaxolol 0.25%-$0.24, pilocarpine 0.5%-Zhenrui-$0.18, pilocarpine 2%-Huming-$0.16, carteolol 1%-Mikelan-$0.15, carteolol 2%-Mikelan-$0.15, pilocarpine 1%-Huming-$0.10, timolol 0.5%-Chengrui-$0.08, timolol 0.5%-Malaisuan Saimaluo'er-$0.03. CONCLUSIONS: The daily cost of glaucoma medications in China ranged much more wildly than developed countries. These data may be useful in selecting medications for glaucoma therapy. The ophthalmic solution of prostaglandins is powerful in reducing intraocular pressure. However, its high price should be considered when selecting glaucoma medications in China.
Pharmacological neuroprotection for glaucoma.
Drugs. 2007; 67(15): 2291
Holló G