intestinal transport

Celiprolol hydrochloride (Selectrol) 是一种选择性肾上腺素受体调节剂，是一种选择性的和具有口服活性的β1肾上腺素受体拮抗剂，具有部分β2激动剂活性，具有降压和抗心绞痛的作用。

(24S)-24,25-Dihydroxyvitamin D3 undergoes multiple hydroxylation processes to form active vitamin D3 analogs.

5-CNAC 是一种口服有效的吸收增强剂，具有无药理活性。它能显著提高与其共同给药的药物（如鲑鱼降钙素）在胃肠道内的吸收效率。5-CNAC 通过非共价可逆结合肽类药物，保护其免受胃肠道酶的降解，并通过增加其脂溶性促进被动跨细胞吸收，同时保持肠道上皮的完整性。5-CNAC 可用于口服肽类的辅助剂研究。

Teduglutide acetate 是一种 GLP-2 类似物，可使小肠黏膜肥大。它通过改变 claudin-10 的分布部分恢复小肠上皮功能，促进钠再循环以进行钠耦合葡萄糖转运和水吸收。

(+)-Biotin 4-amidobenzoic acid is a substrate of biotinidase, which cleaves biotin amide to give biotin in vivo. Biotin is an essential coenzyme for certain carboxylases and is used to modify histones and regulate gene transcription. Biotinidase has key roles in intestinal absorption of biotin, the transport of biotin in plasma, and in the regulation of histone biotinylation. (+)-Biotin 4-amidobenzoic acid is hydrolyzed by biotinidase to release 4-aminobenzoic acid (PABA), which can be quantified by either fluorescent or colorimetric methods. This approach is used in biotinidase activity assays in newborn screening protocols to evaluate biotinidase deficiency.

Urotensin II is a peptide vasoconstrictor and agonist of the urotensin (UT) receptor (Ki= 2.06 nM for the human recombinant receptor expressed in HEK293 cells).1It stimulates intracellular calcium mobilization in HEK293 cells expressing human and rat UT (EC50s = 0.47 and 0.78 nM, respectively) but decreases intracellular calcium concentration in goby (G. mirabilis) enterocytes when used at a concentration of 500 nM.2Urotensin II (20 mU/ml) stimulates active sodium and chloride absorption across isolated goby posterior intestine in 5% seawater-adapted solution.3In vivo, urotensin II (1.5-150 nmol/kg) decreases diastolic blood pressure and increases heart rate in anesthetized rats.4It also reduces the pressor responses to sympathetic nerve stimulation, norepinephrine , and vasopressin in pithed rats when administered at a dose of 150 nmol/kg. 1.Ames, R.S., Sarau, H.M., Chambers, J.K., et al.Human urotensin-II is a potent vasoconstrictor and agonist for the orphan receptor GPR14Nature401(6750)282-286(1999) 2.Loretz, C.A., and Assad, J.A.Urotensin II lowers cytoplasmic free calcium concentration in goby enterocytes: Measurements using quin2Gen. Comp. Endocrinol.64(3)355-361(1986) 3.Loretz, C.A., Freel, R.W., and Bern, H.A.Specificity of response of intestinal ion transport systems to a pair of natural peptide hormone analogs: Somatostatin and urotensin IIGen. Comp. Endocrinol.52(2)198-206(1983) 4.Gibson, A., Wallace, P., and Bern, H.A.Cardiovascular effects of urotensin II in anesthetized and pithed ratsGen. Comp. Endocrinol.64(3)435-439(1986)

(2R)-Glycerol-O-β-D-Galactopyranoside是肠道细菌的乳糖操纵子（lac operon）的天然底物,对RAJI细胞具有抑制效果，广泛应用于生物化学实验和药物合成研究。

Isotachysterol 3 是一种活性维生素 D 结构类似物的开环甾体化合物，也是制备维生素 D₃ 过程中的一种杂质。Isotachysterol 3 在无肾大鼠模型中能够显著刺激肠道钙的转运和骨钙动员。Isotachysterol 3 可用于不依赖于肾脏 1α-羟化的维生素 D 代谢研究。

Butyryl-L-carnitine is a butyrate ester of carnitine. It is an inhibitor of intestinal transporters, blocking carnitine uptake by the carnitine transporter and glycine transport by the amino acid transporter in human retinal pigment epithelial (HRPE) cells (IC50s = 1.5 μM and 4.6 mM, respectively).

Guanylin (human) TFA is a 15-amino acid peptide that serves as an endogenous activator of intestinal guanylate cyclase. This compound is primarily located in the gastrointestinal tract, where it regulates electrolyte and water transport in the intestinal and renal epithelia through a mechanism dependent on cyclic GMP. [1][2]

C2 Adamantanyl globotriaosylceramide (AdaGb3) is a bioactive sphingolipid and water-soluble form of globotriaosylceramide that contains an adamantanyl group in place of the fatty acyl chain. It inhibits Vero toxin binding to globotriaosylceramide in an ELISA assay when used at a concentration of 10 μM. AdaGb3 decreases cell surface expression of P-glycoprotein (P-gp) and reduces efflux of rhodamine 123 in MDCK cells. It also increases apical-to-basal transport of vinblastine in human intestinal C2BBe1 cells.

4-Guanidinobutanoic acid (4-GBA) 是一种 L-精氨酸代谢物，已用于肠道转运研究。 它已专门用于人质子偶联氨基酸转运蛋白 hPAT1。

(-)-WIN 55,212-3 mesylate 是 WIN 55,212-2 mesylate的低活性对映异构体，无神经保护活性和减少肠道运输的作用。(-)-WIN 55,212-3 mesylate是一种大麻素受体激动剂， 可用于研究神经系统疾病。

P-gp inhibitor 4 是一种选择性的 P-glycoprotein 调节剂，EC50值为 94 nM。P-gp inhibitor 4 增加药物通过胃肠道屏障的能力，恢复 doxorubicin 在耐药癌细胞中的毒性。

pTH-Related Protein (1-40) (human, mouse, rat) 促进大鼠肠细胞通过PTHR1受体和PKCα/β信号通路的钙吸收作用。该蛋白增加了甲状旁腺激素1受体（PTHR1）表达，提升了四种跨膜钙转运蛋白—TRPV6、CaBP-D9k、NCX1和PMCA1的水平。

Etrolizumab (rhuMAb Beta7) 是一种人源化的肠道选择性抗 β7 整合素单克隆抗体，可选择性阻断肠道中淋巴细胞的运输和滞留，可用于研究炎症性肠病 (IBD)。

Trimethyl chitosan 是由天然壳聚糖化学改性得到的阳离子聚合物，通过氨基三甲基化增强其水溶性和生物相容性。Trimethyl chitosan 靶向肠道及黏膜上皮细胞紧密连接的吸收增强蛋白，可改善药物在黏膜表面的吸收和稳定性。Trimethyl chitosan 可激发促进亲水性药物跨膜转运的活性，可用于药物递送和合成纳米颗粒。

(+)-Catechin pentaacetate (Catechin pentaacetate) 是儿茶素的酯化衍生物，具有改善肠道形态和功能并积极调节微生物组的潜力，可降低十二指肠中铁和锌转运蛋白。

Endogenous peptide activator of intestinal guanylyl cyclase; secreted mainly by the gastrointestinal mucosa. Regulates water and electrolyte transport in intestinal and renal epithelia.

H-Ala-Ala-OH (L-Alanyl-L-alanine)是一种二肽化合物，能够被Caco-2细胞吸收并引发细胞内的胞质酸化，可作为模型用于研究多肽构象变化。

CSK peptide 是一类用于研究跨越肠黏膜屏障大分子转运能力的多肽，专门靶向杯状细胞，并已应用于口服给药系统的多项研究。