Studies on the variations of monoamineoxidase and acetylcholinesterase activities in the brain under physical environmental conditions

Part 2. Influences of different physical environmental conditions on monoamineoxidase and acetylcholinesterase activities

Abstract

In the previous report, the seasonal variations of monoamineoxidase (MAO) and acetylcholinesterase (Ach-E) activities were observed in the seven parts of rabbit's brains. In this report, the auther investigated the affections of the other environmental conditions (immobilization, cold and noise) on these enzyme activities in the brain parts.
The term, geographic region and experimental procedures were the same as mentioned in the previous report ecxept for the exposure to different physical environmental conditions.
The seasonal variations of enzymatic activities in the 51 adult male albino rabbits in 3 groups were observed in this report by exposing for 2 hours to the different environments: the first group was immobilized by wrapping up their limbs in supine position, the second group was exposed to the cold at -10±2°C, and the third group was exposed to a noise at the level of 100-105 phon characterized by wide octave-band specturm.
The results were as follows:
1. When the season was ignored, the increase of MAO activity in cerebellum and the decrease of Ach-E activity in myelencephalon and cerebellum under the cold condition, and the decrease of Ach-E activity in myelencephalon and cerebellum under the noise condition, were observed as compared with control groups, but under the immobilization signigcant change was not observed in any parts of the brain.
2. The same response pattern of these enzyme activities was observed in the exposure to the different three conditions, as compared with control during the same seasons. But in spite of the exposure to the same condition, a different response pattern was observed in the different season.
3. Without concerning the difference of the exposed conditions, the increase of MAO activity in the summer and the autumn, and the decrease of MAO activity in the winter and the spring, were observed especially in telencephalon, diencephalon, myelencephalon and cerebellum. On the contrary, the decrease of Ach-E activity in the summer and the autumn, and the increase of Ach-E activity in the winter and spring, were observed especially in telencephalon and myelencephalon.
From these results, it may be concluded that the each of these different conditions affected on these enzyme activities but there was no difference in the affection of the each condition, and that the seasonal variation was important for providing the control levels of these enzyme activities in the homeostatic response to another new affection.