Increase of Choline Acetyltransferase by Colchicine in Primary Cell Cultures of Spinal Cord

Publisher Website
Google Scholar
Abstract
Colchicine (5-10 .mu.M) increased choline acetyltransferase (ChAT) activity 5- to 10-fold and suppressed acetylcholinesterase (AChE) and glutamate decarboxylase (GAD) activities to 30 and 50%, respectively, of the levels of control cells in mouse spinal cord cells cultured for several days. The synthesis of radiolabeled acetylcholine (ACh) from [14C]choline was also enhanced 4.6-fold, although the uptake of [14C]choline into cells was decreased to 80% of control level. Neither the incorporation of [3H]leucine into protein nor the total amount of protein was increased by colchicine. Vinblastine also increased ChAT activity while cytochalasin B was not effective. Immunochemical titration study revealed that the increase of ChAT activity by colchicine was due to the accumulation of ChAT molecules. Co-culture of spinal cord cells with skeletal muscle markedly stimulated ChAT activity, and the addition of colchicine to the co-cultures showed greater than additive effect. Colchicine increases ChAT molecules in a specific manner, that the stimulatory effect of colchicine on ChAT activity is possibly mediated via the interaction with microtubules, and that the increase of ChAT activity is based on a mechanism different from that of co-cultures with skeletal muscle cells.