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Choline Acetyltransferase in Bovine Pineal Gland
Author(s) -
PhansuwanPujito P.,
Govitrapong P.,
Ebadi M.
Publication year - 1990
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.1990.tb00691.x
Subject(s) - choline acetyltransferase , pineal gland , muscarinic acetylcholine receptor , cholinergic , endocrinology , medicine , choline , chemistry , receptor , biology , melatonin , biochemistry
Recent studies from our laboratories have shown that the bovine pineal gland contains a muscarinic cholinergic receptor with a K d value of 0.423 ± 0.010 nM and a B max value of 69.75 ± 20.91 fmol/mg protein. In order to substantiate further the possible existence of a pineal cholinergic transmission, we have measured the activity of choline acetyltransferase and delineated its kinetic properties in the bovine pineal gland. This enzyme exhibited an activity of 0.0339 ± 0.0042 nmol/mg protein/min. Furthermore, the bovine pineal choline acetyltransferase possessed a K m , value of 124.86 ± 24.06 μM and a V max value of 0.0598 ± 0.0034 nmol/mg protein/min for acetyl CoA, and a K m value of 3.11 ± 0.94 mM and a V max value of 0.0155 ± 0.0016 nmol/mg protein/min for choline. The presence of muscarinic cholinergic receptors along with a specific choline acetyltransferase are supportive evidences that the bovine pineal gland may receive cholinergic innervation.