Plasma paraoxonase activity in patients with systemic sclerosis.

Background & objectives: Systemic sclerosis (SSc) is a connective tissue disease characterized vascular damage and fi brosis. The aim of this study was to investigate the possible relation between systemic sclerosis and paraoxonase which is an antioxidant enzyme on the HDL. Methods: Twenty nine patients with SSc and 16 healthy subjects (control group) participated in the study. Plasma cholesterol levels, anti-centromere antibody (ACA) levels and paraoxonase (PON) activities were measured. Results: Lower level of high-density lipoprotein (HDL) cholesterol was observed in ACA negative SSc patients than in controls. Paraoxonase activity in ACA positive patients was however found to increase relative to control and ACA negative patient groups. Interpretation & conclusions: Our fi ndings suggested that low HDL level in ACA negative SSc patients might be one of the factors leading to some vascular problems, and increased PON activity in ACA positive SSc group might have some role in the limitation of cutaneous sclerotic process observed in these patients. However, these preliminary fi ndings need to be confi rmed with a larger sample.

A Study on the Distributions of Paraoxonase Activity and the Factors affecting Paraoxonase Activity of a Rural opulation / 예방의학회지

The paraoxonase (E. C. 3.1.1.2.) is a major enzyme to detoxicate the organophosphorus and carbamate which are the most widely used as the agricultural spraying insecticides. To investigate the distributions of plasma paraoxonase activity and the fators affecting the enzyme activity, the plasmas of 945 Korean rural population were analyzed with the modified Krisch's direct sphectro;hotometry method. Three indices of the enzyme activity-basal activity, stimulated activity (by NaCl), % stimulation -were obtained from the analysis. Three indicies suggested unimodal distributions, so we couldn't identify the low activity group; risk group to organophosphorus & carbamate insecticides poisoning. There is no significant relation between 3 activity and the stimulated activity have significant relationship and high coefficient of determination with the activities of their parents (r2=0.30, 0.24; p<0.05), but the % stimulation does not (r2=0.02; p<0.05). These results suggest that the activity of paraoxonase is determined mainly by the genetic factor.