Effects of natriuretic peptides and dopamine on single-unit activity of dorsomedial arcuate neurons in rat brain slices.
The effects of atrial natriuretic peptide (ANP) and C-type natriuretic peptide (CNP) on single-unit activity of dorsomedial arcuate (DM-ARC) neurons were reported. The modulatory effect of CNP on dopamine's (DA) action was also studied. ANP alone in 0.05-0.5 nmol doses induced 26% inhibition and 14% excitation of 37 DM-ARC neurons; the majority (60%) were not responsive. CNP, however, inhibited 46% and excited 4% of 74 DM-ARC neurons. Dose-dependent inhibitory effects of CNP were also observed. In 71 neurons tested with both CNP and DA, more neurons were inhibited by DA (66%) than those by CNP (46%). About one-third (34%) of them were inhibited by both. Furthermore, in 41 neurons inhibited by DA, more than half (54%) of their responses were potentiated by co-administration of CNP. In conclusion, CNP by itself exhibited a predominantly inhibitory action on DM-ARC neurons; and it also potentiated the inhibitory effect of DA on these neurons.
Pan
J T
JT
Department of Physiology, Schools of Life Science and Medicine, National Yang-Ming University, Taipei, Taiwan ROC. jtpan@ym.edu.tw
Lai
C J
CJ
Yen
S H
SH
D000818:Animals; D001111:Arcuate Nucleus of Hypothalamus / Q000166:cytology*; D009320:Atrial Natriuretic Factor / Q000494:pharmacology*; D001921:Brain / Q000166:cytology / Q000187:drug effects; D004298:Dopamine / Q000494:pharmacology*; D004594:Electrophysiology; D005260:Female; D020098:Natriuretic Peptide, C-Type; D009474:Neurons / Q000187:drug effects* / Q000502:physiology; D009924:Organ Culture Techniques; D010052:Ovariectomy; D011506:Proteins / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley
D011506:Proteins; D020098:Natriuretic Peptide, C-Type; D009320:Atrial Natriuretic Factor; D004298:Dopamine