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No Correlation of Pineal “Synaptic” Ribbon Numbers and Melatonin Formation in Individual Rat Pineal Glands
Author(s) -
Vollrath Lutz,
Welker Horst A.
Publication year - 1984
Publication title -
journal of pineal research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.881
H-Index - 131
eISSN - 1600-079X
pISSN - 0742-3098
DOI - 10.1111/j.1600-079x.1984.tb00210.x
Subject(s) - melatonin , pineal gland , medicine , endocrinology , serotonin , biology , pinealocyte , circadian rhythm , receptor
As previous circadian studies of pineal “synaptic” ribbon numbers and melatonin formation suggested that a positive correlation of the two variables exists, in the present investigation this problem was examined in individual pineal glands of rats killed at 1200 h and 2400 h, respectively. For this purpose, one half of the gland was processed for electron microscopy and the ribbons were counted in an area of 20,000 μm 2 tissue; in the other half serotonin N‐acetyltransferase (NAT) activity and melatonin content were determined. No correlation was found to exist between ribbon numbers and pineal NAT activity, pineal melatonin levels and serum melatonin levels, either at day‐ or at nighttime. It is concluded that the ribbons may perhaps be more closely related to the innervation of the pineal gland than to melatonin formation.