CHOLINE ACETYLTRANSFERASE ACTIVITY IN BRAIN OF GOLDFISH ACCLIMATED TO DIFFERENT TEMPERATURES

1. 1. The effect of temperature acclimation on acetylcholine (ACh) synthesis by goldfish brain homogenates prepared from fish acclimated to 8, 15, 25 and 32°C has been investigated. 2. 2. The enzyme responsible for ACh synthesis, choline acetyltransferase, is stable at incubation temperatures higher than previous acclimation temperatures. 3. 3. The activity of the enzyme is greater at higher acclimation temperatures. There was no evident difference in the kinetic properties of the enzyme measured at high incubation temperatures, 39-45°C. 4. 4. At lower incubation temperatures, 15-25°C, the kinetic constants did vary suggesting possible differences in enzyme properties. © 1969.