Calcium-dependent release of XXXX in brain elicited by stimulation of neuropeptide receptors.

@entity4545 @entity1522 @entity2227 @entity2226 @entity1246 @entity2228 @entity2596 @entity141 @entity4022 @entity1510 @entity4556 @entity5624 @entity367 @entity972 @entity4857 @entity815 @entity669
We sought to establish whether the endogenous opiate-receptor agonist @entity4545 ( @entity4545 ) selectively modulates the release of endogenous @entity669 (Tyr) from brain slices prepared from the corpus striatum (CS). @entity1522 ( @entity4556 ) released from slices of CS and, for comparison, cerebral cortex (Cx) were measured by HPLC. Incubation of slices with @entity4545 (1-10 microM) increased the basal release of Tyr (up to 293% of control) from CS, but not Cx, whereas other nonneurotransmitter @entity4556 , @entity815 ( @entity815 ) and @entity4857 ( @entity2596 ), were unchanged. The release of the putative neurotransmitter @entity4556 @entity2227 ( @entity367 ), @entity2226 ( @entity5624 ), and @entity2228 ( @entity4022 ) were similarly increased by 50-150% with @entity4545 in slices of CS, but not Cx. The enhanced release of @entity4556 by @entity4545 was prevented by removal of extracellular @entity141 or by preincubation with the opiate receptor antagonist @entity1510 . Neuronal depolarization by @entity972 (5-55 mM) in the presence of @entity141 did not affect the release of Tyr, whereas release of neurotransmitter @entity4556 such as @entity1246 ( @entity1246 ) were markedly increased. The increase in basal Tyr release by @entity4545 was not the result of a decreased uptake of Tyr. Relative to slices, the basal release of Tyr, @entity815 , and @entity2596 from a synaptosomal (P2) preparation of CS was small (8-51%) compared to that of @entity1246 , @entity4022 , @entity367 , and @entity5624 (49-123%). Nonetheless, @entity4545 (10 microM) markedly increased the release of Tyr (to 833%), but not @entity367 , @entity4022 , and @entity5624 from the P2 fraction.(ABSTRACT TRUNCATED AT 250 WORDS)
