|Budget Amount *help
¥2,200,000 (Direct Cost : ¥2,200,000)
Fiscal Year 1991 : ¥500,000 (Direct Cost : ¥500,000)
Fiscal Year 1990 : ¥1,700,000 (Direct Cost : ¥1,700,000)
(1) Effect of iodinated contrast media on acetylcholinesterase activity
The inhibiting power of contrast media on acetylcholinesterase(AchE) activity was in order : iothalamate > ioxaglate > iopamidol > iohexol. Complete recovery from such inhibition was observed by removing the contrast media from the enzyme. Adding albumin (1%) to the reaction mixture led to a decrease in the inhibitory effect of iozaglate. The contrast media, which have an inhibitory effect on AchE activity in vitro, may have no influence on its activity in blood which contains 4-5% of albumin under physiological conditions.
(2) Effect of iodinated contrast media on angiotensin converting enzyme(ACE)
EDTA inhibits the activity of ACE, but it is contained in the contrast media for the stabilization of drugs. Therefore, it was posturated that the contrast media containing EDTA, may inhibit the activity of ACE. All of the ionic and non-ionic contrast media tested, inhibited the activity of serum ACE, and their decrease of the ACE activity was depend on the dose of the contrast media. The ionic contrast media(iothalamate) which didn't contained EDTA, maintained the activity level of ACE in the serum. But, the non-ionic contrast media(iohexol) which didn't contained EDTA, inhibited the activity of serum ACE. In the inhibition of the activity of ACE, the molecular characteristics of the contrast media, should be considered, in addition to the chelating agent,EDTA.