PIT

• CAT Number: I010448
• CAS Number: 56583-49-4
• Molecular Formula: C20H16N2O5S
• Molecular Weight: 396.42
• Purity: ≥95%
• Synonyms: 4-methylbenzenesulfonic acid;1-oxido-2-pyridin-2-ylindol-1-ium-3-one
• InChI: InChI=1S/C13H8N2O2.C7H8O3S/c16-13-9-5-1-2-7-11(9)15(17)12(13)10-6-3-4-8-14-10;1-6-2-4-7(5-3-6)11(8,9)10/h1-8H;2-5H,1H3,(H,8,9,10)
• InChIKey: MMPTYEXNPWSTOR-UHFFFAOYSA-N
• SMILES: CC1=CC=C(C=C1)S(=O)(=O)O.C1=CC=C2C(=C1)C(=O)C(=[N+]2[O-])C3=CC=CC=N3

PIT (2,2′-Pyridylisatogen tosylate) is a selective and non-competitive antagonist of P2Y1 receptor with an IC50 value of 0.14 μM for human P2Y1 receptor. PIT antagonizes P2Y1 receptor signaling without affecting nucleotide binding. PIT is an irreversible antagonist of responses to ATP at metabotropic purinoceptors (of the P2Y family) in some smooth muscles. PIT can be used for the research of chronic bronchitis and asthma[1][2][3].
PIT (0.1-10 μM) non-competitively and dose-dependently diminishs human P2Y1 receptor signaling with an IC50 value of 0.14 μM[1].
PIT (0.1-10 μM) completely blocks the agonist activity of 2-MeSADP[1].
PIT (1 nM-10 μM) dose-dependently inhibits the accumulation of inositol phosphates induced by the agonist 2-MeSADP[1].
PIT (1 nM-10 μM) dose-dependently blocks the P2Y1 receptor signaling induced by the endogenous agonist ADP[1].
PIT (0.1-3 μM) increases ATP-responses 2-5 fold, while higher concentrations (3-100 μM) inhibits ATP-mediated inward current with an IC50 value of 13.2 μM[2].
PIT shows a low affinity for a range of membrane receptors, including: α1, α2-adrenoceptors, 5-HT1A, 5-HT1B, 5-HT2, 5-HT3, D1, D2, muscarinic, central benzodiazepine, H1, μ-opioid, dihydropyridine and batrachotoxin receptors with pKi values of <5[2]. PIT shows affinity to an adenosine (A1) receptor with a pKi value of 5.3[2]. PIT (12.5-50 μM) irreversibly antagonizes relaxations of ATP in guinea-pig isolated taenia caeca[2].
PIT (10 mg/kg; i.p.; for 5 days) significantly protects both the white matter and the cortical plate lesions against the insult in mice with S-bromo-willardiine injection induced tonic and tonicoclonic seizures[3].

Reference

[1]. Gao ZG, et al. 2,2′-Pyridylisatogen tosylate antagonizes P2Y1 receptor signaling without affecting nucleotide binding. Biochem Pharmacol. 2004 Jul 15;68(2):231-7.
 [Content Brief]

[2]. King BF, et al. Potentiation by 2,2′-pyridylisatogen tosylate of ATP-responses at a recombinant P2Y1 purinoceptor. Br J Pharmacol. 1996 Mar;117(6):1111-8.
 [Content Brief]

[3]. Menton K, et al. Role of spin trapping and P2Y receptor antagonism in the neuroprotective effects of 2,2′-pyridylisatogen tosylate and related compounds. Eur J Pharmacol. 2002 May 24;444(1-2):53-60.
 [Content Brief]