Previous works showed that isolation induced hyperactivity of brain ChE of mice.
Present study was carried out by measuring the effect of exogenous ACTH on such hyperactivity and aggressiveness induced by isolation.
Male albino D. D. O mice weighing 15 g were employed through all the experiments. Each animal was put in plastic cage for a period of 8 weeks. The size of cage for isolation is 10×10×11 cm and for aggregation (5 animals for a cage) is 19×12×12 cm. The walls were painted in black in such a way that the animals could not have visual contacts. Animals were fed a normal balanced diet “ad libitum” and administered with following drugs every two days.
Experimental gr oups were consisted as the following;
A) Isolated mice
1) The group administered with ACTH (10 J. P. U./kg i. p.) ?? ACTH-A
2) The group administere d with solvent of ACTH (i. p.) ?? Controls-A
B) Aggregated mice
1) The group administered with ACTH (10 J. P. U./kg i. p.) ?? ACTH-B
2) The group administere d with solvent of ACTH (i. p.) ?? Controls-B
The degree of aggressi veness was evaluated according to the method described by Allee-Scott and from such degree animals were classified into “victorious mice” and “defeated mice.” The test was performed every Saturday for a period. At the end of the period of isolation and aggregation animals were decapitated in different times (0′, 15′, 30′, 60′, 120′ after eserine treatment (0.2 mg /kg i. p.) and biochemical procedure were carried out in these brains by measuring ChE activity with the method described by Hesterin.
Results;
1) The relation between the period of isolation and aggressiveness:
Aggressiveness of ACTH-A was markedly enhanced up to 6 th week of isolation and after this week such enhancement was slowley become, while aggressiveness of controls-A was rapidly elevated up to 8 th week of isolation and after this week such rapidity was markedly declined.
2) The influence of isolation on body weight:
Body weights of the aggregated mice of both group were found to be significantly lower than the isolated mice of which the victorious mice were significantly greater than the defeated mice in either case.
3) Brain ChE activity:
a) Hyperactivity of bra in ChE in isolated mice were found in either case.
a) Hyperactivity of brain ChE in isolated mice were found in either case.
b) Administration of ACTH declined this enzymatic activity in different degree in either isolation or aggregation.
c) Isolation of mice inhibited slightly the effect of eserine on above enzymatic activity.
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