Secretoneurin releases dopamine from rat striatal slices: a biological effect of a peptide derived from secretogranin II (chromogranin C).
Proteolytic processing of secretogranin II (chromogranin C) in brain leads to the formation of a 33-amino acid peptide which we have named secretoneurin. All the properties of secretoneurin are consistent with the concept that this peptide represents a neuropeptide. However, a biological function has not yet been demonstrated. Therefore, we have now investigated whether secretoneurin could alter transmitter release in brain. Slices of rat caudate-putamen were superfused in an in vitro system and dopamine was measured in the superfusate. Secretoneurin dose-dependently increased the outflow of dopamine. This response was abolished in Ca(2+)-free medium. The secretoneurin-response could also be blocked by preincubation of the peptide with a specific antiserum and was subject to rapid specific and reversible desensitization. This effect on dopamine release constitutes the first discovered biological effect found for a peptide derived from secretogranin II. Thus, secretoneurin can be added to the ever-growing number of neuropeptides.
Department of Psychiatry, University of Innsbruck, Austria.
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A
Saria
J
J
Troger
R
R
Kirchmair
R
R
Fischer-Colbrie
R
R
Hogue-Angeletti
H
H
Winkler
D000818:Animals; D002421:Caudate Nucleus / Q000378:metabolism; D002864:Chromogranins / Q000378:metabolism*; D003342:Corpus Striatum / Q000378:metabolism*; D004298:Dopamine / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D004558:Electric Stimulation; D066298:In Vitro Techniques; D009479:Neuropeptides / Q000096:biosynthesis / Q000494:pharmacology*; D010477:Perfusion; D011506:Proteins; D011699:Putamen / Q000378:metabolism; D051381:Rats; D053381:Secretogranin II
D002864:Chromogranins; D009479:Neuropeptides; D011506:Proteins; D053381:Secretogranin II; C081159:secretoneurin; D004298:Dopamine