Monocrotaline (MCT) - The lung-killer

  • pneumotoxic macrocyclic pyrrolizidine alkaloid churned out by a number of exciting plants
  • causes a pulmonary vascular syndrome, which essentially means that a bunch of things go wrong with the blood supply to your lungs, including:
    • proliferative pulmonary vasculitis (spreading inflammation of the wall of blood vessels in the lung)
  • used to intentionally produce pulmonary hypertension in animals in order to create an experimental model for investigating the pathophysiology of pulmonary hypertension and the development of pharmacological means of treating it
  • has been hypothesized that it is biotransformed in the liver to a feisty little reactive metabolite that then travels via the blood to the lungs where it starts messing with endothelial cells, altering their function to cause detrimental structural changes in pulmonary blood vessels (particularly the arteries)
  • its selectivity for the lung likely has something to do with the way it is biotransformed by the liver and the manner in which blood circulates through the lungs (vs. any other part of the body)
Tanino Y. [Monocrotaline-induced pulmonary hypertension in animals] Nippon Rinsho. 2001 Jun;59(6):1076-80. Review. Japanese.
Wilson DW et al. Mechanisms and pathology of monocrotaline pulmonary toxicity. Crit Rev Toxicol. 1992;22(5-6):307-25. Review.

2 chemically inspired comments:

David said...

My first thought was why the lungs, and like most places, I didn't expect an answer, but I'm mighty glad you didn't leave any loose ends!

Anonymous said...


What's the connection with rattlesnakes?

Inquiring minds want to know.