Lanthanum (La) - The hidden binder of phosphate

  • rare earth element (atomic number 57) named after the Greek word lanthano, meaning to lie hidden, in reference to the fact that the dude who discovered it found it 'hiding' in a sample of another rare earth element, cerium
    • lanthanum carbonate (Fosrenol) is a phosphate binder, which is a drug used to curtail the gastrointestinal absorption of phosphate from ingested food
    • phosphate binders are an important pharmacological means of alleviating hyperphosphatemia (excessively high blood phosphate levels) in people with chronic renal failure, who are unable to remove phosphate from their body because their kidneys aren't working properly
    • hyperphosphatemia can promote the breakdown of bone, potentially leading to bone deformation, pain, and increased susceptibility to fractures
  • lanthanum carbonate is also used, in an industrial setting, to produce lanthanum strontium manganite, used to make solid oxide fuel cells
  • since it is so good at binding up phosphate, lanthanum is commonly found in pool products intended to remove phosphates, a source of nourishment for algae, from pool water
  • a number of rare earth chlorides, including lanthanum chloride, are capable of inhibiting the clotting of blood
  • has been reported to modulate neurotransmitter systems, including the potentiation of receptors for inhibitory GABA and glycine receptors (which suggests that lanthanum may depress brain function)
- Albaaj F, Hutchison AJ. Lanthanum carbonate (Fosrenol): a novel agent for the treatment of hyperphosphataemia in renal failure and dialysis patients. Int J Clin Pract. 2005 Sep;59(9):1091-6. Review.
- Chang CW, Qu B, Hong Z, Gao GD. Potentiation of inhibitory amino acid receptors-mediated responses by lanthanum in rat sacral dorsal commissural neurons. Neurotoxicol Teratol. 2006 Nov-Dec;28(6):657-63. Epub 2006 Aug 30.
- http://en.wikipedia.org/wiki/Lanthanum

1 chemically inspired comments:

Jim's Words Music and Science said...

I'm having a little trouble seeing what is surprising here. Lanthanides have been known to cleave RNA by transesterification and hydrolysis for a long time, and they bind the phosphodiesters in the process. Heavy metals are toxic: even those that are required trace elements (like molybdenum) are only desirable in a narrow concentration window. What am I missing that should be shocking or stunning me?