The substance P fragment SP(1-7) stimulates motor behavior and nigral dopamine release.
Earlier studies have shown that the undecapeptide substance P (SP) alters motor behavior and dopamine metabolism following injection into the substantia nigra (SN) in rat, even though the SN appears largely devoid of SP-specific (NK-1) receptors. In this report, intra-nigral injections of the amino-terminal SP fragment SP(1-7) enhanced rearing, sniffing and locomotor activity, and increased the nigral DOPAC-to-DA ratio. In addition, SP(1-7) increased 3H-DA release from the SN in vitro. These findings suggest that some of the effects of nigral SP on motor behavior and dopamine release are mediated by amino-terminal fragments of SP.
Department of Biochemistry, University of Colorado Health Sciences Center, Denver 80262.
M E
ME
Hall
J M
JM
Stewart
D015102:3,4-Dihydroxyphenylacetic Acid / Q000378:metabolism; D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects; D015306:Biogenic Monoamines / Q000378:metabolism; D004298:Dopamine / Q000378:metabolism*; D007276:Injections, Intraventricular; D008297:Male; D009043:Motor Activity / Q000187:drug effects*; D010446:Peptide Fragments / Q000008:administration & dosage / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D013373:Substance P / Q000008:administration & dosage / Q000494:pharmacology*; D013378:Substantia Nigra / Q000187:drug effects / Q000378:metabolism*
D015306:Biogenic Monoamines; D010446:Peptide Fragments; D015102:3,4-Dihydroxyphenylacetic Acid; D013373:Substance P; C036877:substance P (1-7); D004298:Dopamine