C(27)-steroid hormones calcitriol and ecdysterone activates hydrolysis of neutral lipids--cholesterol esters and triacylglycerols--in its early pregenomic phase of action.

Abstract

We have examined in vivo capacities of two C27-steroid hormones-phytoecdysteroid ecdysterone (20-hydroxyecdysone, 10(-8)M) and calcitriol (1 alpha, 25-dihydroxyvitamin D3, 10(-12)M), as a modulators of neutral lipids hydrolysis in the brain and heart cells. Severe lines of evidence indicate that both hormones may acts as positive regulators of cholesterol esters and triacylglycerol hydrolysis in early (0.5-30 min) pregenomic phase of its actions, yielding known (DAG, free polyunsaturated fatty acids) and possible (free cholesterol) lipid second messengers.