Abstract
The detective sensitivity of apolipoprotein(a) [apo(a)] isoform measurement by immunoblotting was determined and the prevalence of apo(a) isoform in patients with diabetes mellitus or with coronary artery stenosis was examined. The detective limit was from 4 to 6ng of lipoprotein(a) [Lp(a)] loaded per lane in electrophoresis. There was no cross-reactivity with plasminogen of the anti-apo(a) antibody used in our immunoblotting system. Apo(a) isoform containing a smaller size of apo(a) was detected more frequently in cases with high Lp(a) concentration, and was more frequent in patients with non-insulin independent diabetes mellitus (NIDDM) of a higher Lp(a) concentration than in other disease groups. The frequency of higher Lp (a) concentration cases in patients with coronary artery stenosis was larger than that in normal controls among each identical apo(a) isoform group, suggesting that mechanisms other than genetic factor was involved in the Lp(a) increase in the patients with coronary artery stenosis.
