Cyclic ADP-ribose (cADPR) is an effective calcium mobilization second messenger, which is synthesized from NAD + by ADP-ribosyl cyclase. Cyclic ADP-ribose mainly increases cytosolic calcium through Ryanodine receptor-mediated endoplasmic reticulum release
Thrombin receptor agonist peptide (TRAP-14) is a 14-amino acid peptide agonist of the α-thrombin receptor. It induces aggregation of washed platelets as well as platelets in citrated and hirudin plasma. TRAP-14 (100 μM) increases the cytosolic calcium concentration in isolated guinea pig pulmonary smooth muscle cells 5-fold over baseline. It increases pulmonary arterial pressure in isolated guinea pig lung when used at a concentration of 1 μM, which is comparable to the effect induced by 10 nM α-thrombin. TRAP-14 also induces contraction of isolated rat aortic rings and increases endothelin-1 (ET-1) levels in a dose-dependent manner, an effect that is reversed by the ETA antagonist BQ-123 and the nitric oxide synthase (NOS) inhibitor L-NNA .
The group IVA phospholipase A2 (PLA2), known as calcium-dependent cytosolic PLA2 (cPLA2), selectively releases arachidonic acid from membrane phospholipids, playing a central role in initiating the synthesis of prostaglandins and leukotrienes. AX 048 is a potent group IVA cPLA2 inhibitor that demonstrates 50% inhibition of the enzyme at a mole fraction (XI(50)) of 0.022. Pretreatment with AX 048 (ED50 = 1.2 mg kg) dose-dependently reduces thermal hyperalgesia evoked by carrageenan injection of rat hind paw. At concentrations as high as 30 μM, AX 048 does not inhibit COX activity or interfere with central cannabinoid receptor signaling.
5(S),6(R)-DiHETE is a dihydroxy polyunsaturated fatty acid and a nonenzymatic hydrolysis product of leukotriene A4 (LTA4). Mouse liver cytosolic epoxide hydrolase catalyzes the conversion of LTA4 to 5(S),6(R)-DiHETE. It is a weak LTD4 receptor agonist in guinea pig lung membranes. It induces guinea pig ileum contraction with an ED50 value of 1.3 μM.
Cyclic ADP-ribose ammonium (cADPR ammonium) is a powerful calcium mobilization second messenger synthesized from NAD+ by an ADP-ribosyl cyclase. It primarily raises cytosolic calcium levels through Ryanodine receptor-mediated release from the endoplasmic reticulum, while also facilitating extracellular influx through the opening of TRPM2 channels [1][2][3].
Bourgeonal is an agonist of human testicular olfactory receptor hOR17-4. It increases cytosolic calcium levels in human spermatozoa, acts as a chemoattractant, and increases swimming speed in sperm chemotaxis assays in a concentration-dependent manner.
Variabilin, a novel inhibitor of human platelet aggregation, it is a potent RGD (Arg-Gly-Asp)-containing antagonist of the fibrinogen receptor glycoprotein IIb-IIIa (GPIIb-IIIa; αIIbβ3) and the vitronectin receptor αvβ3.Variabilin is also an antimicrobial furanosesterterpene. Variabilin is an inhibitor of human secretory and cytosolic phospholipase A2 (PLA2) activities that controls eicosanoid production in vitro and in vivo, inhibits neutrophil degranulation and superoxide generation in vitro and shows anti-inflammatory activity after topical or p.o. administration to mice.