Cholinesterases of the gall bladder.

Cholinesterase histochemistry of the human gall bladder was studied using two specific methods. Distribution of acetylcholinesterase: In the mucosa, nerve fascicles consisting of densely packed parallel single nerve fibres, small ganglia and "spot"- and "glomerule"- like concentrations of acetylcholinesterase activity were observed. In the muscle layer, a wide-meshed network of delicate nerves, with occational areas of very dense innervation, and small ganglia were seen. In the serosa, "glomerule"- like structures surrounded by dense "baskets" of delicate nerves were observed.-- The general scheme of distribution of non-specific cholinesterases was similar to that of acetylcholinesterase. It seems that the cholinergic innervation of the gall bladder is related to both secretion and absorption and contractility. Some cholinergic nerves are probably sensory, especially because acetylcholinesterase-positive structures, possibly pressure of stretch receptors, supplied with nerves were observed in the mucosa and the serosa. The cholinergic innervation of the gall bladder muscle was scarce except occasional areas of very dense innervation. It may thus be concluded that the intermuscle spread of excitation plays an important role, the majority of the smooth muscle cells receiving their nervous influence via electrotonic coupling.