P. Phansuwan‐PujitoP. GovitrapongM. EbadiMahidol UniversityUniversity of Nebraska Medical Center, College of Medicine2018-06-142018-06-141990-01-01Journal of Pineal Research. Vol.9, No.1 (1990), 29-381600079X074230982-s2.0-0025033293https://repository.li.mahidol.ac.th/handle/20.500.14594/15923Recent 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. Copyright © 1990, Wiley Blackwell. All rights reservedMahidol UniversityBiochemistry, Genetics and Molecular BiologyArticleSCOPUS10.1111/j.1600-079X.1990.tb00691.x