| Bioactivity | U-73122 is a phospholipase C (PLC) and 5-LO (5-lipoxygenase) inhibitor with an IC50of 1-2.1 µM for PLC. | ||||||||||||
| Invitro | U-73122 potently inhibits receptor-coupled activation of PLC in membranes isolated from PMNs[1]. U-73122 inhibits N-formyl-methionyl-leucyl-phenylalanine-induced aggregation of human polymorphonuclear neutrophils (PMN) and the associated production of IP3 and diacyglycerol[2]. U-73122 markedly inhibits inositol phosphate release elicited by either oxotremorine-M or guanosine-5'-O-(3-thiotriphosphate) than that induced by added Ca2+ in digitonin-permeabilized cells[3]. | ||||||||||||
| In Vivo | U73122 significantly attenuates TNF-α mRNA expression, has no effect on sham animals, but significantly increases heart work and rate of contraction and relaxation without affecting heart rate in endotoxemic mice[4]. U73122 (400 nM/μL) significantly reduces total lordosis durations, compared to vehicle infusions to the VTA, of oestradiol and progesterone-primed hamsters. VTA infusions of U73122 do not alter motor behaviour of hamsters in the activity monitor, but there is a significant effect of muscimol to decrease total number of beam breaks compared to hamsters administered SKF38393[5]. | ||||||||||||
| Name | U-73122 | ||||||||||||
| CAS | 112648-68-7 | ||||||||||||
| Formula | C29H40N2O3 | ||||||||||||
| Molar Mass | 464.64 | ||||||||||||
| Appearance | Solid | ||||||||||||
| Transport | Room temperature in continental US; may vary elsewhere. | ||||||||||||
| Storage |
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| Reference | [1]. Smith RJ, et al. Receptor-coupled signal transduction in human polymorphonuclear neutrophils: effects of a novel inhibitor of phospholipase C-dependent processes on cell responsiveness. J Pharmacol Exp Ther. 1990 May;253(2):688-97. [2]. Bleasdale JE, et al. Selective inhibition of receptor-coupled phospholipase C-dependent processes in human platelets and polymorphonuclear neutrophils. J Pharmacol Exp Ther. 1990 Nov;255(2):756-68. [3]. Thompson AK, et al. The aminosteroid U-73122 inhibits muscarinic receptor sequestration and phosphoinositide hydrolysis in SK-N-SH neuroblastoma cells. A role for Gp in receptor compartmentation. J Biol Chem. 1991 Dec 15;266(35):23856-62. [4]. Peng T, et al. Disruption of phospholipase Cgamma1 signalling attenuates cardiac tumor necrosis factor-alpha expression and improves myocardial function during endotoxemia. Cardiovasc Res. 2008 Apr 1;78(1):90-7. Epub 2007 Dec 12. [5]. Frye CA, et al. In the ventral tegmental area, the membrane-mediated actions of progestins for lordosis of hormone-primed hamsters involve phospholipase C and protein kinase C. J Neuroendocrinol. 2007 Sep;19(9):717-24. [6]. Hörnig M, et al. Inhibition of 5-lipoxygenase by U73122 is due to covalent binding to cysteine 416. Biochim Biophys Acta. 2012 Feb;1821(2):279-86. [7]. Xie W, et al. 3Beta-hydroxy-6-aza-cholestane and related analogues as phosphatidylinositol specific phospholipase C (PI-PLC) inhibitors with antitumor activity. Bioorg Med Chem. 2000 Apr;8(4):699-706. |