Cholinesterase activity in the harderian gland of anas domesticus

Abstract

Abstract The histochemical localization and quantitative levels of acetylcholinesterase and butyrylcholinesterase have been determined in the Harderian glands of normal ducks and ducks fed with salt to increase their serum sodium concentrations; there was no significant difference between the two groups. Acetylcholinesterase was present at a mean concentration of 68.2 μM/gm/hour (range 65.5 – 72.7 μM/gm/hour) in the normal animals and 67.6 μM/gm/hour (range 63.8 – 76.4 μM/gm/hour) in the salt‐fed group; the enzyme was present in nerves related to blood vessels. Butyrylcholinesterase was present at a mean concentration of 42.5 μM/gm/hour (range 20.4 – 58.7 μM/gm/hour) in the control animals and 40.2 μM/gm/hour (range 29.3 – 61.3 μM/gm/hour) in the salt‐fed group; the enzyme was present in epithelial cells and in nerves related to blood vessels similar to those containing acetylcholinesterase. There was a close correlation between the subjective assessment of cholinesterase activity based on histochemical techniques and the amount quantitatively measured. The gland probably secretes mucus and lipids; the epithelial butyrylcholinesterase may play a role in lipid metabolism in the tissue. The nerves may regulate the flow of blood through the gland.