(-)-p-Bromotetramisole Oxalate (Synonyms: (-)-p-Bromotetramisole, L-para-Bromotetramisole)

(-)-p-Bromotetramisole Oxalate (L-(-)-p-Bromotetramisole Oxalate, L-p-Bromotetramisole Oxalate, (-)-4-Bromotetramisole Oxalate) is a potent and non-specific inhibitor of alkaline phosphatase and is also an inhibitor of protein tyrosine phosphatases [1] [2].

Alkaline phosphatase is a hydrolase enzyme that removes phosphate groups from nucleotides, proteins and alkaloids. Protein tyrosine phosphatase is an enzyme that removes phosphate groups from phosphorylated tyrosine residues on target proteins.

(-)-p-Bromotetramisole Oxalate is an inhibitor of alkaline phosphatase and protein tyrosine phosphatases. In various rat tissues, (-)-p-Bromotetramisole Oxalate (0.1 μM) completely inhibited non-specific alkaline phosphatase [1]. In rat zona glomerulosa, (-)-p-Bromotetramisole Oxalate (100 μM) blocked the inhibition of Na+ pump (Na+, K+-ATPase) induced by angiotensin II. The result suggested that inhibition of the Na+ pump induced by angiotensin II might be mediated by a tyrosine phosphatase [2]. In neurosecretory PC12 cells, (-)-p-Bromotetramisole Oxalate (0.3 mM) increased ionomycin-stimulated noradrenaline (NA) release, which suggested that tyrosine phosphorylation regulated Ca2+-stimulated NA release [3].

In Sprague-Dawley rats, (-)-p-Bromotetramisole Oxalate (10 μM) significantly increased fractional excretion of phosphate (FEPi) from 4.7% to 13.4% [4].

References:
[1].  Borgers M, Thoné F. The inhibition of alkaline phosphatase by L-p-bromotetramisole. Histochemistry, 1975, 44(3): 277-280.
[2].  Yingst DR, Davis J, Schiebinger R. Inhibitors of tyrosine phosphatases block angiotensin II inhibition of Na(+) pump. Eur J Pharmacol, 2000, 406(1): 49-52.
[3].  Kitamura T, Murayama T, Nomura Y. Enhancement of Ca2+-induced noradrenaline release by vanadate in PC12 cells: possible involvement of tyrosine phosphorylation. Brain Res, 2000, 854(1-2): 165-171.
[4].  Onsgard-Meyer M, McCoy AL, Knox FG. Effect of bromotetramisole on renal phosphate excretion. Proc Soc Exp Biol Med, 1996, 213(2): 193-195.