Abstract
Recently, it was found that Apo B comprises Apo B-48, derived from the small intestine, and Apo B-100, derived from the liver, and metabolic differences between them have been investigated. Nestel and the present authors have noted that a higher ratio of Apo B-48 is recognizable in triglyceride (TG)-rich lipoproteins in patients with chronic renal insufficiency. However, since the cause of this retention of Apo B-48 in VLDL was entirely unknown, we clinically studied the acceleration of retention and inhibitory factors.
As Apo B-48 ratios in VLDL (Apo B-48/(Apo B-100+Apo B-48)) were higher than those in healthy subjects, positive correlations with plasma TG levels and total amounts of VLDL were noted. The ratio of Apo B-48 in VLDL was increased when lipids were orally loaded. As for the changes before and after hemodialysis, the Apo B-48 ratio in VLDL was decreased 2h after hemodialysis using heparin as an anticoagulant. Similarly, when Apo E was increased and Apo C was decreased in VLDL 2h after hemodialysis using heparin as an anticoagulant, the Apo E/C ratio was increased. On the other hand, before and after hemodialysis using gabexate mesilate (FOY) as an anticoagulant, no changes were noted in VLDL-fraction Apo B-48, Apo E and Apo C.
It was suggested from the above findings that an increase of Apo E and a decrease of Apo C are important in the metabolism of Apo B-48 in the liver of patients with hemodialysis, and that Apo B-48 is more easily metabolized in the liver when the Apo E/C ratio is increased.
