lipocalin-type

AT56 是口服有活性的脂钙蛋白型前列腺素 D 合酶 (L-PGDS) 选择性抑制剂，其IC50=95 μM，Ki=75 μM。它能够特异性地抑制L-PGDS 催化的 PGD2介导的嗜睡或疼痛反应。

Prostaglandin D2 is synthesized by hematopoietic-type PGD-synthase (H-PGDS) in mast cells and is released in large quantities during allergic and asthmatic anaphylaxis. PGD2 is also produced in the brain by lipocalin-PGD-synthase also known as β-trace. In the brain, PGD2 produces normal physiological sleep and lowering of body temperature. Further pharmacological actions include inhibition of platelet aggregation and relaxation of vascular smooth muscle. tetranor-PGDM is a major metabolite of PGD2 that is detectable in human and mouse urine. The levels of tetranor-PGDM and 2,3-dinor-11β-PGF2α , a related PGD2 metabolite, in human urine were found to be 1.5 ± 0.3 and 0.6 ± ng mg creatinine, respectively. tetranor-PGDM was detected in murine urine at a level of 8.1 ± 1.3 ng mg creatinine.

TAS 205 is an inhibitor of hematopoietic prostaglandin D synthase (H-PGDS; IC50= 55.8 nM).1It is selective for H-PGDS over lipocalin-type PGDS (L-PGDS) at 100 μM, as well as over enzyme and receptor panels at 10 μM. TAS 205 inhibits production of prostaglandin D2induced by A23187 in KU812 human and RBL-2H3 rat basophils with IC50values of 78.3 and 181.3 nM, respectively. It inhibits ovalbumin-induced nasal lavage fluid eosinophil infiltration and late-phase nasal obstruction in an ovalbumin-sensitized guinea pig model of allergic rhinitis when administered at a dose of 30 mg kg. 1.Aoyagi, H., Kajiwara, D., Tsunekuni, K., et al.Potential synergistic effects of novel hematopoietic prostaglandin D synthase inhibitor TAS-205 and different types of anti-allergic medicine on nasal obstruction in a Guinea pig model of experimental allergic rhinitisEur. J. Pharmacol.875173030(2020)

Prostaglandin D2 (PGD2) is a primary enzymatic prostaglandin derived from PGH2 and is abundantly produced in the cerebrospinal fluid (CSF) by the lipocalin-type PGD synthase, and peripherally by myeloid cells such as mast cells and basophils via a hematopoietic-type PGD synthase. PGD2 is chemically unstable and presents challenges for use and analysis due to its brief in vivo half-life. Δ12-PGD2, an initial decomposition product of PGD2, acts as an intermediate in the pathway to Δ12-PGJ2, a cyclopentenone prostaglandin known for its antimitotic and carcinogenic properties. The metabolism of Δ12-PGD2 involves the addition of thiol nucleophiles, a common pathway for many cyclopentenone prostaglandins.

Prostaglandin D2 (PGD2) is one of the five principal prostaglandins enzymatically derived from PGH2. It is abundantly generated in the cerebrospinal fluid (CSF) by lipocalin-type PGD synthase and in peripheral regions by myeloid cells, such as mast cells and basophils, via leukocyte-type PGD synthase. The compound 1,25-trans-PGD2 is an isomer of PGD2, characterized by the alteration of the double bond between carbons 5 and 6 from cis(Z) to trans(E). This trans isomer, found as a 2-5% impurity in most commercial PGD2 bulk drug preparations, is primarily synthesized as an analytical standard to identify and quantify this impurity. Based on existing studies of trans isomers of F-type prostaglandins, 5-trans-PGD2 likely exhibits biological activity comparable to its cis isomer, although no specific published reports confirm this for 5-trans-PGD2.