ATP-SENSITIVE K-WITHDRAWAL( CHANNEL OPENERS INHIBIT MORPHINE)

We studied the effects of two different ATP-sensitive K+ channel opene rs on naloxone-precipitated withdrawal in morphine-dependent mice. The i.c.v. administration of cromakalim and diazoxide (both at 5-40 mu g/ mouse) dose-dependently inhibited several signs of morphine withdrawal (number of jumps and episodes of forepaw tremors, and body weight los s). At present it is impossible to specify the exact mechanism(s) invo lved in this effect. However, considering that morphine opens K+ chann els in neurons, it is tempting to suggest that K+ channel openers can mimic the effects of morphine on neuronal K+ currents, and as a conseq uence can act as substitutes for this drug during morphine withdrawal.