The effect of ACTH on suckling rats

In the present study, the causes of brain shrinkage induced by synthetic ACTH treatment in epileptic children were investigated using suckling rats. Synthetic ACTH was injected subcutaneously once a day for 5 days into suckling rats aged 15 days. Saline was injected into control subjects in the same way. Rats were sacrificed before the injection, immediately after the repeated injections, and 5 and 14 days from the end of the course of repeated injections. The weight, volume and water content of the brains were measured and the protein, DNA, sodium and potassium contents of the brains were also determined. The mean weight and volume of the brains after 5-day injection of ACTH were slightly smaller compared to those of control rats. No natural increase in brain protein with growth was found from the start of ACTH injections to 14 days after finishing the course of repeated injections. The DNA, sodium and potassium contents of the brains significantly increased immediately after the repeated injections of 5 days. It was suggested that the brain shrinkage of epileptics induced by ACTH treatment might be caused by decreased water content and not cellular degradation.