Distribution, Isolation and Sequence Analysis of the C-Terminal Heptapeptide of Pro-Enkephalin A (YGGFMRF) from the Ovine Median Eminence.
Abstract Using a polyclonal antiserum raised against the C-terminal heptapeptide of pro-enkephalin A, we have isolated the opioid heptapeptide Tyr-Gly-Gly-Phe-Met-Arg-Phe (MERF) from ovine median eminence and mapped its distribution in that structure. MERF-immunoreactivity was confined to the pars externa (neurosecretory zone) where it colocalized with corticotrophin-releasing factor in the majority of terminals. No larger, N-terminally extended forms of MERF were detected in median eminence extracts suggesting that pro-enkephalin is fully processed to its constituent enkephalin congeners, and that the bioactive products, including MERF, act at the level of the hypothalamus in regulating anterior pituitary function.
Giraud
A S
AS
Department of Medicine, The University of Melbourne, Western Hospital, Footscray, Victoria 3011, Australia.
Clarke
I J
IJ
Rundle
S E
SE
Parker
L M
LM
Funder
J W
JW
Simpson
R J
RJ
Smith
A I
AI