Plasma Lecithin: Cholesterol Acyltransferase Activity in Hypo- and Hyperthyroidism[*] [**]

Abstract

The plasma lecithin: cholesterol acyltransferase (LCAT) activity was determined in 5 normal subjects and in 5 hypo- and 7 hyperthyroid patients by measuring the decrease of lecithin and the esterification of cholesterol during a 18 hrs incubation period. The absolute decrease in lecithin and the increase in esterified cholesterol were significantly higher in the hypothyroid group than in the other groups, whereas the percentage decrease in lecithin was similar in all three groups. In order to exclude the influence of changes in substrate an assay system was used which contained lipoprotein-free plasma and a defined amount of substrate. Under these conditions the esterification did not show any difference in the eu-, hypo- and hyperthyroid subjects.

The results suggest that the concentration of the LCAT in plasma is in the normal range in patients with thyroid disorders and that the turnover of lecithin and unesterified cholesterol depends on their concentration in plasma. The data were compared to those obtained from patients with a cirrhosis of the liver.

Key words

Lecithin:Cholesterol Acyltransferase - Hypothyroidism - Hyperthyroidism - Liver Cirrhosis

1 To Prof. Dr. Ruhenstroth-Bauer on his 60th birthday

2 Presented in part at the 19. Symposium der Deutschen Gesellschaft für Endokrinologie, Berlin, February, 1973

1 To Prof. Dr. Ruhenstroth-Bauer on his 60th birthday

2 Presented in part at the 19. Symposium der Deutschen Gesellschaft für Endokrinologie, Berlin, February, 1973