BLT2 antagonist-1 (compound 15b) is a selective inhibitor of the BLT2 receptor, impeding the chemotaxis of CHO-BLT2 cells at an IC50 of 224 nM, while not affecting CHO-BLT1 cell chemotaxis. It blocks the interaction between LTB4 and the BLT2 receptor with a K_i of 132 nM and may serve as a research tool for inflammatory airway diseases, including asthma and chronic obstructive pulmonary disease [1].

BLT2 Probe 1 (Compound 13), a fluorescent probe derived from the synthetic BLT2 agonist CAY10583, offers a robust tool for exploring BLT2 receptor ligand pharmacology across various assay systems [1]. As BLT2 is a valuable target for treatments in diabetic wound healing and gastrointestinal lesions, this probe facilitates relevant biomedical research.

The effects of Leukotriene B4 (LTB4) are mediated by two known receptors, BLT1 and BLT2. LTB4 is a high affinity ligand for BLT1, and many of its pro-inflammatory effects are believed to be transduced through this receptor. The BLT2 is more enigmatic, in that LTB4 is not a high-affinity ligand, nor is it clear that BLT2 activation promotes inflammation. LTB4 ethanolamide (LTB4-EA) is a theoretical 5-LO metabolite of arachidonoyl ethanolamide (AEA). In CHO cells transfected with human BLTR1, LTB4-EA was a potent antagonist with about three times greater affinity for the receptor than LTB4 (Ki = 1.22 nM versus 3.88 nM). LTB4-EA antagonizes the LTB4-induced contractions of guinea pig lung parenchyma with an EC50 of 10 nM. LTB4-EA thus represents a potential endogenous anti-inflammatory compound functioning as a natural antagonist of BLTR1.

Leukotriene B4 (LTB4) compounds are produced by both enzymatic and non-enzymatic processes. The products of enzymatic origin, via Leukotriene A4 (LTA4) hydrolase, are stereospecifically 12(R). Non-enzymatic hydrolysis products are 50:50 mixtures at C-12, but are almost exclusively trans at C-6. Thus, the non-enzymatic hydrolysis product of LTA4 is 6-trans-12-epi LTB4. 12-epi LTB4 is an isomer which would not be expected to occur in either non-enzymatic hydrolysis products, or in the enzymatic products of LTA4 hydrolase. Compared to LTB4, 12-epi LTB4 has significantly reduced activity for the LTB4 receptor on human neutrophils (IC50 of 7.5 mM), and on guinea pig lung membranes with a (Ki of 4.7 mM). 12-epi LTB4 is an weak agonist at both the recombinant human BLT1 and BLT2 receptors, requiring approximately 10 mM for full activation of the receptor.

20-hydroxy LTB4 is a metabolite of LTB4 in human neutrophils. In human leukocytes, LTB4 is inactivated by the enzyme LTB4 20-hydroxylase. 20-hydroxy LTB4 is not only much less active (~5%) compared to LTB4 in causing degranulation of PMNL, but actually inhibits LTB4-induced degranulation of human neutrophils (Ki = 13.3 nM). However, 20-hydroxy LTB4 is as active as LTB4 in contracting parenchymal strips from guinea pig lung. 20-hydroxy LTB4 retains considerable ligand binding affinity at the BLT2 receptor, but does not appear to function as an agonist.

Leukotriene B4 (LTB4)-3-aminopropylamide is an analog of LTB4 that exhibits potent and selective binding to the BLT1 receptor with Ki values of 5.1 nM at BLT1 and 1,227 nM at BLT2, indicating its high affinity for BLT1 over BLT2. This compound's effects are mediated through interactions with two receptors, BLT1 and BLT2.

CAY10583 is an agonist of leukotriene B4 receptor type 2 (BLT2). CAY10583 directly promotes keratinocyte migration and indirectly enhances fibroblast proliferation by increasing keratinocyte production of bFGF1 and TGF-β, leadng to accelerate wound closur

Leukotriene B4 (LTB4) is a dihydroxy fatty acid derived from arachidonic acid through the 5-lipoxygenase pathway. It promotes a number of leukocyte functions including aggregation, stimulation of ion fluxes, enhancement of lysosomal enzyme release, superoxide anion production, chemotaxis, and chemokinesis. At least two LTB4 receptors, termed BLT1 and BLT2, have been identified. 14,15-dehydro LTB4 is a LTB4 receptor antagonist that has a higher binding affinity for BLT1, demonstrating a Ki value of 27 nM, compared to BLT2, which has a Ki value of 473 nM. 14,15-dehydro LTB4 inhibits LTB4-induced release of lysozymes from rat polymorphonuclear leukoctyes with an IC50 value of 1 μM.

LY255283 is a specific antagonit of leukotriene B4 (LTB4) receptor. It inhibits the production of LTB(4) in human peripheral blood polymorphonuclear leukocytes (PMNL) and in monocytes activated by calcium ionophore A23187.