Noradrenaline activates vasopressin neurons via alpha1-receptor-mediated Ca2+ signaling pathway.
Noradrenaline (NA) (1-10 microM), dibutyryl-cAMP (1-5 mM), and forskolin (10-20 microM) increased cytosolic Ca2+ concentration ([Ca2+]i) in isolated arginine-vasopressin (AVP)-containing neurons in the hypothalamic supraoptic nucleus (SON). The NA-induced increase in [Ca2+]i in AVP-containing neurons was abolished by a specific alpha1-antagonist, prazosin (1 microM) and was markedly reduced when treated with a protein kinase A (PKA) blocker, H89 (40 microM). The NA-induced [Ca2+]i was not altered by a protein kinase C (PKC) inhibitor, calphostin C (0.1 microM) and a PKC activator, TPA (100 nM). In general, NA, a known neurotransmitter in the SON, activates AVP-containing neurons via alpha1-receptor which is linked to stimulation of cAMP-PKA-regulated Ca2+ signaling pathway.
Shioda
S
S
Department of Anatomy, Showa University School of Medicine, Shinagawa-ku, Tokyo, Japan. shioda@med.showa-u.ac.jp
Yada
T
T
Muroya
S
S
Takigawa
M
M
Nakai
Y
Y
D000818:Animals; D001127:Arginine Vasopressin / Q000819:agonists*; D002118:Calcium / Q000502:physiology*; D008297:Male; D009474:Neurons / Q000187:drug effects*; D009638:Norepinephrine / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D018340:Receptors, Adrenergic, alpha-1 / Q000187:drug effects*; D015398:Signal Transduction / Q000187:drug effects*
D018340:Receptors, Adrenergic, alpha-1; D001127:Arginine Vasopressin; D002118:Calcium; D009638:Norepinephrine