Glycyl-L-glutamine regulates the expression of asymmetric acetylcholinesterase molecular forms in cultured cardiac post-natal myocytes.

Asymmetric acetylcholinesterase (AChE) forms were associated with pre-natal but not post-natal ventricular myocytes, when myocytes were cultured in a defined medium on laminin-coated plates for 72 h. In contrast, globular AChE molecular forms were associated with both pre-natal and post-natal myocytes. Glycyl-L-glutamine (10(-4) or 109-6) M), but not glycyl-D-glutamine or glycyl-L-glutamate, induced the expression of asymmetric AChE molecular forms by the cultured post-natal myocytes. Neither of the three dipeptides altered the specific activity of cell-associated AChE in the cultured post-natal ventricular myocytes. Tetrameric globular (G4) AChE was the main AChE form secreted by cultured pre-natal and post-natal cardiac myocytes. The secretion rate of AChE from post-natal myocytes was not affected by the addition of glycyl-L-glutamine. These results suggest that glycyl-L-glutamine has a trophic effect on at least one of the components of the post-synaptic cholinergic system in developing rat heart.