CAS number  YesY
Jmol-3D images Image 1
Molecular formula C8H11ClN4
Molar mass 198.65 g mol−1
Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)

MK-212 (CPP or 6-chloro-2-(l-piperazinyl)pyrazine)[1] is a serotonin agonist.[2] It promotes the secretion of serum prolactin and cortisol in humans.[3]


In an experiment performed by Clineschidt and colleagues, they dosed mice with varying concentrations of MK-212, and observed its effects.[4] The result correlated very well to binding of indolealkylamine receptors, such as the serotonin and tryptamine receptors, which shows four characteristics. Namely, increased frequency of muscle twitching, increased twitching of the head, "an increase in the strength of the crossed extensor reflex in the acutely spinalized rat", and the cause of complex motor syndrome.[4]


  1. ^ Clineschidmt, BV (1979). "MK-212: A serotonin-like agonist in the CNS". General pharmacology 10 (4): 287–90.  
  2. ^ Bastani, B.; Nash, J. F.; Meltzer, H. Y. (1990). "Prolactin and Cortisol Responses to MK-212, a Serotonin Agonist, in Obsessive-Compulsive Disorder". Archives of General Psychiatry 47 (9): 833–9.  
  3. ^ Lowy, Martin T.; Meltzer, Herbert Y. (1988). "Stimulation of serum cortisol and prolactin secretion in humans by MK-212, a centrally active serotonin agonist". Biological Psychiatry 23 (8): 818–28.  
  4. ^ a b Clineschmidt, Bradley (1977). European Journal of Pharmacology 44: 65–74.