Tetrahydrobiopterin ((Rac)-Sapropterin) is a cofactor of the aromatic amino acid hydroxylases enzymes and also acts as an essential cofactor for all nitric oxide synthase (NOS) isoforms.

MicMicroglial cell cultures under hyperoxia are supplemented or not with an effective dose of Tetrahydrobiopterin (BH4) (100 μM). Exposure of microglial cells to hyperoxia-induced oxidative stress for 24 h reveals a robust increase in TSP-1 mRNA expression and protein compare to normoxia (21% O₂). Tetrahydrobiopterin supplementation significantly prevents hyperoxia-induced microglial activation by diminishing Iba-1 and TSP-1 expression and prevents microvascular injury in choroidal explants^[1].

MCE has not independently confirmed the accuracy of these methods. They are for reference only.

To assess the levels of Tetrahydrobiopterin in the retina, three to five pools of retinas are collected from WT and hph-1mice at postnatal age 7, 14, and 22 and evaluated by LC-MS/MS. LC-MS/MS analysis confirm a significant decrease by approximately 90% in the concentration levels of Tetrahydrobiopterin in retinal tissue from hph-1 mice (0.0009±0.0006; p<0.0001, 0.01±0.001; p<0.0001 and 2.45±0.40; p<0.005) compare to the WT group (0.014±0.001, 0.092±0.01, and 23.13±6.44) at P7, P14, and P22, respectively^[1].

MCE has not independently confirmed the accuracy of these methods. They are for reference only.

241.25

C₉H₁₅N₅O₃

17528-72-2

四氢生物蝶呤；沙丙蝶呤

Room temperature in continental US; may vary elsewhere.

DMSO : 50 mg/mL (207.25 mM; Need ultrasonic)

请根据产品在不同溶剂中的溶解度选择合适的溶剂配制储备液；一旦配成溶液，请分装保存，避免反复冻融造成的产品失效。
储备液的保存方式和期限：-80°C, 6 months; -20°C, 1 month。-80°C 储存时，请在 6 个月内使用，-20°C 储存时，请在 1 个月内使用。

请根据您的实验动物和给药方式选择适当的溶解方案。以下溶解方案都请先按照 In Vitro 方式配制澄清的储备液，再依次添加助溶剂：

——为保证实验结果的可靠性，澄清的储备液可以根据储存条件，适当保存；体内实验的工作液，建议您现用现配，当天使用； 以下溶剂前显示的百
分比是指该溶剂在您配制终溶液中的体积占比；如在配制过程中出现沉淀、析出现象，可以通过加热和/或超声的方式助溶

• 1.

  请依序添加每种溶剂：;10% DMSO ;; 40% PEG300 ;; 5% Tween-80 ;; 45% saline

  Solubility: ≥ 2.5 mg/mL (10.36 mM); Clear solution

  此方案可获得 ≥ 2.5 mg/mL (10.36 mM，饱和度未知) 的澄清溶液。

  以 1 mL 工作液为例，取 100 μL 25.0 mg/mL 的澄清 DMSO 储备液加到 400 μL PEG300 中，混合均匀；向上述体系中加入50 μL Tween-80，混合均匀；然后继续加入 450 μL生理盐水定容至 1 mL。

  将 0.9 g 氯化钠，完全溶解于 100 mL ddH₂O 中，得到澄清透明的生理盐水溶液

• 2.

  请依序添加每种溶剂：;10% DMSO ;; 90% (20% SBE-β-CD in saline)

  Solubility: ≥ 2.5 mg/mL (10.36 mM); Clear solution

  此方案可获得 ≥ 2.5 mg/mL (10.36 mM，饱和度未知) 的澄清溶液。

  以 1 mL 工作液为例，取 100 μL 25.0 mg/mL 的澄清 DMSO 储备液加到 900 μL 20% 的 SBE-β-CD 生理盐水水溶液中，混合均匀。

  将 2 g 磺丁基醚 β-环糊精加入 5 mL 生理盐水中，再用生理盐水定容至 10 mL，完全溶解，澄清透明
• 3.

  请依序添加每种溶剂：;10% DMSO ;; 90% corn oil

  Solubility: ≥ 2.5 mg/mL (10.36 mM); Clear solution

  此方案可获得 ≥ 2.5 mg/mL (10.36 mM，饱和度未知) 的澄清溶液，此方案不适用于实验周期在半个月以上的实验。

  以 1 mL 工作液为例，取 100 μL 25.0 mg/mL 的澄清 DMSO 储备液加到 900 μL玉米油中，混合均匀。

• [1]. Rivera JC, et al. Tetrahydrobiopterin (BH4) deficiency is associated with augmented inflammation and microvascular degeneration in the retina. J Neuroinflammation. 2017 Sep 6;14(1):181.

Microglia cell line (SIM-A9) is used and cultured. Briefly, microglial cells (800, 000 cells per well) are cultured in 6-well plates with DMEM/F12 (1:1) supplementing with 10% fetal bovine serum (FBS), 5% of horse serum (HS), and 1% penicillin/streptomycin. After 24 h, the cells are starved with DMEM/F12 (1:1) free of FBS and HS for 6 h. Then, microglial cells cultures in presence or absence of 100 μM of Tetrahydrobiopterin are exposed to hyperoxia (75% oxygen and 25% nitrogen) in a modular incubator chamber and maintained in a humidified CO₂ incubator at 37 °C for 24 h. Microglial cells in matching controls are incubated at 37 °C in an incubator with 95% air and 5% CO₂ and collected at the same time point. Cell lysates are quickly processed for RNA. The conditioning media is stored at -80 and later used in choroidal explant assay^[1].

MCE has not independently confirmed the accuracy of these methods. They are for reference only.

Mice pups are exposed with their mothers in a 75% oxygen environment from postnatal day 7 to P9 using oxycycler to induce retinal vaso-obliteration (VO). Animals are anesthetized and injected intravitreally at P7 with 100 μM of Tetrahydrobiopterin or vehicle (sterile PBS 1×) using a syringe equipped with 50-gauge glass capillary. At P9, mice pups are sacrificed and retinas are dissected and stained overnight at 4 °C with fluorescein-labeled Griffonia Simplicifolia Lectin 1 (GSL 1), isolectin B4 (1:100) with 1 mM CaCl₂ in PBS. Quantification of VO is assessed using the computer software^[1].

MCE has not independently confirmed the accuracy of these methods. They are for reference only.

• [1]. Rivera JC, et al. Tetrahydrobiopterin (BH4) deficiency is associated with augmented inflammation and microvascular degeneration in the retina. J Neuroinflammation. 2017 Sep 6;14(1):181.