SPECIES AND AGE-DEPENDENT DIFFERENCES OF FUNCTIONAL COUPLING BETWEEN OPIOID DELTA-RECEPTOR AND G-PROTEINS AND POSSIBLE INVOLVEMENT OF PROTEIN-KINASE-C IN STRIATAL MEMBRANES
N. Fukushima et al., SPECIES AND AGE-DEPENDENT DIFFERENCES OF FUNCTIONAL COUPLING BETWEEN OPIOID DELTA-RECEPTOR AND G-PROTEINS AND POSSIBLE INVOLVEMENT OF PROTEIN-KINASE-C IN STRIATAL MEMBRANES, Neuroscience letters, 176(1), 1994, pp. 55-58
[D-Ser(2),Leu(5)]-enkephalin-Thr(6) (DSLET) and [D-Pen(2,5)]-enkephali
n (DPDPE), both delta-agonists, stimulated the high affinity GTPase in
the rat striatal membranes in a naltrindole-reversible manner. Simila
r stimulation was also observed in the striatal membrane preparations
of 16-week-old guinea pigs, while not in those preparations of 4-week-
old ones. When calphostin C, a protein kinase C inhibitor, was added t
o the reaction mixture, DSLET showed a marked stimulation in this acti
vity in 4-week guinea pig striatal membranes. There was no effect of K
T5720, a cyclic AMP-dependent protein kinase inhibitor, on such delta-
opioid-mediated responses. These findings suggest that protein kinase
C is locally involved in the functional uncoupling of delta-receptors
to G-proteins in the striatum of young guinea pigs.