[achistikbenny]

A pharmaceutical company has developed a drug that prevents egress of Mg+2 from N-methyl D aspartame (NMDA) receptor. What is most likely effects of this drug in a patient with acute stroke?

A) Decreased risk of seizures because of hypomagnesima
B) Facilitation of Ca entry into neuron and enhancement of excitation mediated cell death
C) Hyperpolarization of membrane and conduction block
D) Prevention of Ca+2 entry into neuron and reduction of excitation mediated cell death
E) Rapid depolarization of membrane with lowering of seizure threshold

 

[just_md]

Voltage-dependent, after co-activation by two ligands - glutamate and glycine, influx of Na+ and small amounts of Ca2+ ions into the cell and K+ eflux.
Choice B. And receptors are NR2B and NR2A subunits which have differential roles in mediating exitoxic neuronal death

 

[drmodi44]

i think its D as the Given Drug prevent Mg+2 egress from NMDA receptors...so more mg+2 will be avilable der...and mg+2 is endogenous antagonist which prevents opening of ion channels...so it will decrease influx of ca+2....

 

[achistikbenny]

hey , ur completely rt. the ans is D.

 

[just_md]

OK

It's vice-versa. Thanks