Evidence for post-translational processing of auriculin B to atriopeptin III immediately prior to secretion by hypothalamic neurons in culture.
In rats, the precursor of atrial natriuretic peptide (ANP) is produced and processed into its smaller congeners in the heart and the brain. We have demonstrated that a congener of ANP, auriculin B (ANP4-28), was present in long term monolayer cultures of neonatal rat hypothalamic neurons. In addition, forskolin and 3-isobutyl-1-methyl-xanthine (IBMX) augmented the cellular content of auriculin B in a dose dependent manner. Thus, cyclic AMP may act as an intracellular signal for modulating the functional development of hypothalamic immunoreactive (ir) ANP producing neurons. Furthermore, our data suggest that the form of ANP released from these cultures, following either forskolin treatment alone or forskolin treatment followed by acute high potassium depolarisation, was atriopeptin III (ANP5-28). Thus atriopeptin III, rather than auriculin B, may represent the endogenous ligand for ANP receptors in the central nervous system.
Neuroendocrine Laboratory, Mental Health Research Institute of Victoria, Royal Park Hospital, Parkville, Australia.
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Dean
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Copolov
D015056:1-Methyl-3-isobutylxanthine / Q000494:pharmacology; D000818:Animals; D009320:Atrial Natriuretic Factor / Q000235:genetics* / Q000378:metabolism; D002478:Cells, Cultured; D002851:Chromatography, High Pressure Liquid; D002852:Chromatography, Ion Exchange; D005576:Colforsin / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D007031:Hypothalamus / Q000166:cytology / Q000378:metabolism*; D009474:Neurons / Q000378:metabolism*; D010446:Peptide Fragments; D011499:Protein Processing, Post-Translational
D010446:Peptide Fragments; D005576:Colforsin; C062525:atrial natriuretic factor prohormone (103-126); D009320:Atrial Natriuretic Factor; D015056:1-Methyl-3-isobutylxanthine