The influence of neuropeptides on amine synthesis: Cholecystokinin-8 and neurotensin reduce striatal tyrosine hydroxylase activity.
Cholecystokinin-8 and neurotensin, neuropeptides found in relatively high concentrations in some catcholaminergic neurons and/or terminal or cell body areas, reduced native and polyanion-activated rat striatal tyrosine hydroxylase activity, but not that of the enzyme activated by phosphorylating conditions. Substance P, ?(3)-melanocyte-stimulating hormone, [d-ala(2), d-leu(5)]-enkephalin, or thyrotropin-releasing hormone had no effect on the native enzyme or on either activated form. Cholecystokinin-8 and neurotensin may interact with polyanion-activated or membrane bound-activated tyrosine hydroxylase to modulate its activity.
Hole
K
K
Department of Psychiatry, University of California, San Diego, La Jolla, CA 92093, U.S.A.
Russo
P V
PV
Mandell
A J
AJ