Effects of gap junction blocker on vasopressin and vasoactive intestinal polypeptide rhythms in the rat suprachiasmatic nucleus in vitro.
We examined effects of gap junction blockers, octanol and halothane, on circadian rhythms in the release of arginine-vasopressin (AVP) and vasoactive intestinal polypeptide (VIP) in suprachiasmatic nucleus (SCN) slice cultures of the rat. Circadian rhythms in AVP and VIP release maintained when the SCN culture was treated with octanol for 42 h. However, the release of AVP and VIP showed no circadian rhythms after 7 days incubation with octanol or halothane. Circadian rhythmicity in the two peptide rhythms appeared after the removal of the drug from the culture medium. These findings suggested that the gap junction communication may be involved in intercellular coupling within each subpopulation of AVP or VIP neurons in the SCN.
Shinohara
K
K
Department of Physiology, Yokohama City University School of Medicine, Yokohama, Japan. kazuyuki@med.yokohama-cu.ac.jp
Funabashi
T
T
Mitushima
D
D
Kimura
F
F
D000818:Animals; D002450:Cell Communication / Q000187:drug effects; D002940:Circadian Rhythm / Q000187:drug effects; D017077:Culture Media, Conditioned / Q000737:chemistry; D017629:Gap Junctions / Q000187:drug effects / Q000378:metabolism*; D006221:Halothane / Q000494:pharmacology; D066298:In Vitro Techniques; D009474:Neurons / Q000187:drug effects / Q000378:metabolism; D000442:Octanols / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D013493:Suprachiasmatic Nucleus / Q000166:cytology / Q000378:metabolism*; D014660:Vasoactive Intestinal Peptide / Q000032:analysis / Q000378:metabolism*; D014667:Vasopressins / Q000032:analysis / Q000378:metabolism*
D017077:Culture Media, Conditioned; D000442:Octanols; D014667:Vasopressins; D014660:Vasoactive Intestinal Peptide; D006221:Halothane