Stimulation of dopamine output from adrenal medullary cells by beta-endorphin and its C-terminal tetrapeptide (MPF).
The output of dopamine from cultures of rat adrenal medullary strips was increased by 71-120% when Lys-Lys-Gly-Glu (MPF), the C-terminal tetrapeptide sequence of human beta-endorphin, was added to the culture medium at 100 micrograms/ml concentration. Human beta-endorphin caused a 44% increase, but an N-terminal fragment of its molecule and somatotrophin caused no increase. Results with analogs of MPF show that small structural change of the C-terminal Glu residue causes complete loss of activity.
Department of Environmental and Evolutionary Biology, University of Liverpool, U.K.
D M
DM
Ensor
J S
JS
Morley
R M
RM
Redfern
J B
JB
Miles
D000313:Adrenal Medulla / Q000187:drug effects / Q000378:metabolism*; D000818:Animals; D004151:Dipeptides / Q000494:pharmacology*; D004298:Dopamine / Q000378:metabolism*; D004723:Endorphins / Q000378:metabolism / Q000494:pharmacology*; D066298:In Vitro Techniques; D010446:Peptide Fragments; D051381:Rats; D011919:Rats, Inbred Strains
D004151:Dipeptides; D004723:Endorphins; D010446:Peptide Fragments; C050079:lysyl-lysyl-glycyl-glutamic acid; D004298:Dopamine