Multiple Molecular Forms of Acetylcholinesterase in Rat Vagus Nerve, Smooth Muscle, and Heart

Extracts of rat tissues were subjected to ultracentrifugation on linear density gradients of sucrose (5–20%) and fractions of these gradients were analyzed for acetylcholinesterase (AChE) activity. Most of the AChE activity in extracts of vagus nerve was found to sediment at 10S. However, 16S AChE, previously thought to be confined to somatic motor nerves and skeletal muscle, was observed to accumulate rapidly at a nerve ligation. A search for this rapidly sedimenting form of AChE was carried out in tissues receiving vagal innervation. Significant amounts of 16S AChE were detected in the heart, especially in the right atrium, and in several regions of the gut. It was concluded that 16S AChE is distributed more widely than has previously been recognized.