title: Circadian variations of neuropeptide Y-like immunoreactivity in the rat pineal gland.
abstract: Neuropeptide Y, which is present in the sympathetic nerves innervating pineal glands, has been shown to affect N-acetyltransferase activity and melatonin production. Using enzyme immunoassay, we measured daily patterns of neuropeptide Y (NPY) in rat pineal glands in light-dark cycles (LD) and in constant darkness (DD). NPY within rat pineal glands displayed daily rhythms in LD with a peak at zeitgeber time 16. Similar rhythms in the NPY content were also observed in DD. These rhythms have a similar phase-relationship to that of the rhythm of NAT activity, suggesting that NPY in rat pineal glands plays a role in circadian rhythms of NAT activity.
authors.affiliation: Laboratory of Integrative Brain Function, Mitsubishi Kasei Institute of Life Science, Tokyo, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Shinohara
authors.forename: S T
authors.initials: ST
authors.lastname: Inouye
mesh_terms: D000818:Animals; D002940:Circadian Rhythm / Q000502:physiology*; D003624:Darkness; D007124:Immunoenzyme Techniques; D007150:Immunohistochemistry; D008297:Male; D009478:Neuropeptide Y / Q000276:immunology / Q000378:metabolism*; D010870:Pineal Gland / Q000276:immunology / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar
chemical_list: D009478:Neuropeptide Y