β1-adrenergic receptor ( Ki = 0.76 nM ); β2-adrenergic receptor ( Ki = 32.6 nM )

体外活性：Levobetaxolol 有效拮抗克隆人 β1 和 β2 受体以及豚鼠心房 β1、气管 β2 和大鼠结肠 β3 受体的功能活性，IC50 分别为 33.2 nM、2970 nM 和 709 nM。左倍他洛尔 (Ki = 16.4 nM) 在抑制人非色素性睫状上皮细胞中异丙肾上腺素诱导的 cAMP 产生方面比右旋倍他洛尔 (Ki = 2.97 μM) 更有效。左倍他洛尔（局部应用）已被证明能够以足够的量到达眼睛后部，以保护视网膜神经节细胞免受各种类型的损伤。左倍他洛尔在大鼠皮质中取代 [3H]-尼群地平作为 L 型电压依赖性钙通道受体，IC50 为 29.5 μM。左旋倍他洛尔可将 NMDA 刺激的 45Ca2+ 流入减少 47.3%。左旋倍他洛尔（局部应用）可降低缺血/再灌注引起的 b 波振幅。

左倍他洛尔（150 mg/眼）比右旋倍他洛尔更有效，可将清醒的高眼压食蟹猴的眼内压降低 25.9%。 Levobetaxolol (20 mg/kg) 可显着保护视网膜功能，并导致光诱导的视网膜病变大鼠模型中 RPE 和外核层显着增厚。 Levobetaxolol (20 mg/kg) 导致 bFGF 上调 10 倍，CNTF mRNA 水平上调两倍，这些营养因子已被证明可以抑制许多物种的视网膜变性。

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测定了左倍他洛尔的药理学特征，并将其与其他β肾上腺素受体拮抗剂的活性进行了比较。左贝他洛尔（β1选择性的43倍）对克隆的人β1（Ki=0.76 nM）受体的亲和力高于β2（Ki=32.6 nM），而右贝他洛尔对这两种受体的亲和力要弱得多。左旋紫杉醇能有效拮抗克隆的人β1和β2受体的功能活性，也能拮抗豚鼠心房β1、气管β2和大鼠结肠β3受体的功能活动（IC50分别为33.2 nM、2970 nM和709 nM）。因此，左倍他洛尔的β1选择性是β2的89倍。在抑制异丙肾上腺素诱导的人非色素睫状上皮细胞中cAMP的产生方面，左炔诺洛尔（Ki=16.4 nM）比右倍他洛尔（Ki=2.97 microM）更有效。左丁醇和（1）-噻吗洛尔对β1和β2受体具有高度亲和力，但β1选择性明显低于左倍他洛尔。左旋、右旋和外消旋倍他洛尔除了在σ位点和Ca2+通道（IC50＞1微M）以及89个其他受体/配体结合位点外，几乎没有亲和力。左替洛尔对L型Ca2+通道表现出微摩尔的亲和力。在清醒的眼高血压食蟹猴中，左倍他洛尔比右倍他洛尔更有效，在150微克/只眼睛的剂量下将眼压降低了25.9+/-3.2%（n=15-30）。定量[3H]-左倍他洛尔放射自显影显示，其与人类睫状突、虹膜、脉络膜/视网膜和睫状肌的结合水平很高。总之，左倍他洛尔是一种强效、高亲和力和β1选择性的降眼压β肾上腺素受体拮抗剂。[1]

Rats were dosed (IP) with vehicle or levobetaxolol (10 and 20 mg kg(-1)) 48, 24 and 0 hr prior to exposure for 6 hr to fluorescent blue light. The electroretinogram (ERG) and retinal morphology were assessed after a 3 week recovery period. Evaluation of the ERG demonstrated significant protection of retinal function in levobetaxolol (20 mg kg(-1))-dosed rats compared to vehicle-dosed rats. Similarly, the RPE and outer nuclear layer were significantly thicker in levobetaxolol (20 mg kg(-1))-dosed rats compared to vehicle-dosed rats. To elucidate potential mechanism(s) of the neuroprotective activity of levobetaxolol, bFGF and CNTF mRNA levels in normal rat retinas were evaluated 12 hr after a single i.p. injection. Northern blot analysis of levobetaxolol treated retinas demonstrated a 10-fold up-regulation of bFGF and a two-fold up-regulation of CNTF mRNA levels, trophic factors that have been shown to inhibit retinal degeneration in a number of species. These studies suggest that levobetaxolol can be used as a novel neuroprotective agent to ameliorate retinopathy.[3]

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20 mg/kg

Hypertensive cynomolgus monkeys

Absorption, Distribution and Excretion
Levobetaxolol is applied topically to the eye but some does reach systemic circulaton with a Tmax of 3 h.

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Biological Half-Life
The mean half life of levobetaxolol is 20 h.

[1]. J Ocul Pharmacol Ther . 2001 Aug;17(4):305-17.

[2]. Brain Res Bull . 2004 Feb 15;62(6):525-8.

[3]. Exp Eye Res . 2002 Apr;74(4):445-53.

Levobetaxolol Hydrochloride is the hydrochloride salt form of levobetaxolol, the S-isomer of the -selective beta-1 adrenergic receptor antagonist betaxolol with anti-glaucoma activity and devoid of intrinsic sympathomimetic activity. When applied topically in the eye, levobetaxolol reduces aqueous humor secretion and lowers the intraocular pressure (IOP).
See also: Levobetaxolol (has active moiety).

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Glaucoma is a chronic optic neuropathy in which retinal ganglion cells die over a number of years. The initiation of the disease and its progression may involve an ischaemic-like insult to the ganglion cell axons caused by an alteration in the quality of blood flow. Thus, to effectively treat glaucoma it may be necessary to counteract the ischaemic-like insult to the region of the optic nerve head. Studies on the isolated optic nerve suggest that substances that reduce the influx of sodium would be particularly effective neuroprotectants. Significantly, of the presently used antiglaucoma substances, only beta-blockers can reduce sodium influx into cells. Moreover, they also reduce the influx of calcium and this would be expected to benefit the survival of insulted neurones. Betaxolol is the most effective antiglaucoma drug at reducing sodium/calcium influx. Our electroretinographic data indicated that topical application of levobetaxolol to rats attenuated the effects of ischaemia/reperfusion injury. Timolol was also effective but to a lesser extent. Based on these data we conclude that beta-blockers may be able to blunt ganglion cell death in glaucoma, and that levobetaxolol may be a more effective neuroprotectant than timolol because of its greater capacity to block sodium and calcium influx.[2]

C18H30CLNO3

343.89

343.191

C, 62.87; H, 8.79; Cl, 10.31; N, 4.07; O, 13.96

116209-55-3

Betaxolol; 63659-18-7; Betaxolol hydrochloride; 63659-19-8

60656

White to off-white solid powder

448ºC at 760 mmHg

224.7ºC

8.26E-09mmHg at 25°C

3.586

50.72

3

4

11

23

286

1

Cl[H].O(C([H])([H])C([H])([H])C1C([H])=C([H])C(=C([H])C=1[H])OC([H])([H])[C@]([H])(C([H])([H])N([H])C([H])(C([H])([H])[H])C([H])([H])[H])O[H])C([H])([H])C1([H])C([H])([H])C1([H])[H]

CHDPSNLJFOQTRK-LMOVPXPDSA-N

InChI=1S/C18H29NO3.ClH/c1-14(2)19-11-17(20)13-22-18-7-5-15(6-8-18)9-10-21-12-16-3-4-16;/h5-8,14,16-17,19-20H,3-4,9-13H2,1-2H3;1H/t17-;/m0./s1

(2S)-1-[4-[2-(cyclopropylmethoxy)ethyl]phenoxy]-3-(propan-2-ylamino)propan-2-ol;hydrochloride

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

注意： 请将本产品存放在密封且受保护的环境中，避免吸湿/受潮。

Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

配方 1 中的溶解度: ≥ 2.5 mg/mL (7.27 mM) (饱和度未知) in 10% DMSO + 40% PEG300 + 5% Tween80 + 45% Saline (这些助溶剂从左到右依次添加，逐一添加), 澄清溶液。
例如，若需制备1 mL的工作液，可将100 μL 25.0 mg/mL澄清DMSO储备液加入到400 μL PEG300中，混匀；然后向上述溶液中加入50 μL Tween-80，混匀；加入450 μL生理盐水定容至1 mL。
*生理盐水的制备：将 0.9 g 氯化钠溶解在 100 mL ddH₂O中，得到澄清溶液。

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配方 2 中的溶解度: ≥ 2.5 mg/mL (7.27 mM) (饱和度未知) in 10% DMSO + 90% (20% SBE-β-CD in Saline) (这些助溶剂从左到右依次添加，逐一添加), 澄清溶液。
例如，若需制备1 mL的工作液，可将 100 μL 25.0 mg/mL澄清DMSO储备液加入900 μL 20% SBE-β-CD生理盐水溶液中，混匀。
*20% SBE-β-CD 生理盐水溶液的制备（4°C，1 周）：将 2 g SBE-β-CD 溶解于 10 mL 生理盐水中，得到澄清溶液。

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配方 3 中的溶解度: 120 mg/mL (348.95 mM) in PBS (这些助溶剂从左到右依次添加，逐一添加), 澄清溶液; 超声助溶.

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请根据您的实验动物和给药方式选择适当的溶解配方/方案：
1、请先配制澄清的储备液(如：用DMSO配置50 或 100 mg/mL母液(储备液));
2、取适量母液，按从左到右的顺序依次添加助溶剂，澄清后再加入下一助溶剂。以 下列配方为例说明 (注意此配方只用于说明，并不一定代表此产品 的实际溶解配方):
10% DMSO → 40% PEG300 → 5% Tween-80 → 45% ddH2O (或 saline);
假设最终工作液的体积为 1 mL, 浓度为5 mg/mL: 取 100 μL 50 mg/mL 的澄清 DMSO 储备液加到 400 μL PEG300 中，混合均匀/澄清；向上述体系中加入50 μL Tween-80，混合均匀/澄清；然后继续加入450 μL ddH2O (或 saline)定容至 1 mL；
3、溶剂前显示的百分比是指该溶剂在最终溶液/工作液中的体积所占比例;
4、 如产品在配制过程中出现沉淀/析出，可通过加热(≤50℃)或超声的方式助溶;
5、为保证最佳实验结果，工作液请现配现用！
6、如不确定怎么将母液配置成体内动物实验的工作液，请查看说明书或联系我们;
7、 以上所有助溶剂都可在 Invivochem.cn网站购买。