[The suppression of CK activity in the brain by acrylamide]

In vitro, both acrylamide and bis-acrylamide inhibited the activity of purified creatine kinase (CK) from the human brain with almost the same potency. The inhibition was dose-dependent and non-competitive. In vivo, however, only acrylamide caused the splay of hind limbs and an awkward gait in rats, and inhibited CK activity in the brain. The CK activity of the regions of the brain investigated differed, and these distributions were well matched with those of human cases. The inhibition became more marked as the administration of acrylamide was repeated. While the distribution of 14C in the different regions of the brain did not differ after the injection of [14C] acrylamide, the degree of the suppression of CK activity differed in these regions and was most marked in the hypothalamus. Fifty-two-week-old rats appeared more susceptible to acrylamide than 8-week-old rats. However, no difference in the inhibition of the CK activity in the brain was noted between the older and the young ones. The possible relation of the regional differences of CK suppression with the pathogenesis of acrylamide encephalopathy is discussed.