Ueda H, Misawa H, Fukushima N, Takagi H
Eur J Pharmacol. 1987 Jun 12;138(1):129-32. doi: 10.1016/0014-2999(87)90348-7.
DAGO, a specific opioid mu-agonist stimulated the low Km GTPase activity of membranes of the guinea-pig striatum at 1-1000 nM and this effect was antagonized by naloxone 10-100 nM. On the other hand, U-50,488H, a specific opioid kappa-agonist inhibited the low Km GTPase activity of membranes of the guinea-pig cerebellum at 1-100 nM. As this effect was antagonized by MR2266 but not by naloxone, the findings suggest that opioid mu- and kappa-receptor stimulation is probably linked to the stimulation and inhibition of low Km GTPase, respectively.
