Sex difference in cholesterol esterase activity in rats adipose tissues and changes of the activity following orchiectomy and ovariectomy.

: Sex differences in cholesterol esterase activity and changes in the activity in response to orchiectomy and ovariectomy were investigated in rat adipose tissue in association with serum lipid levels. Cholesterol esterase activity in the parametrial adipose tissue was 65% higher than that in the epididymal adipose tissue, but there were no sex differences in the activity of subcutaneous and perirenal adipose tissue. Pre- and post-pubertal orchiectomy resulted in a marked enhancement of cholesterol esterase activity, whereas ovariectomy significantly reduced the activity. Serum cholesterol and triacylglycerol levels were elevated through orchiectomy but ovariectomy had no effect. These results suggest that cholesterol esterase activity in the adipose tissue around sexual organs is regulated by gonadal hormones and that the increase in serum cholesterol due to orchiectomy is unlikely to be related to the change in the enzyme activity.