Related Experiment Video
Updated: Aug 17, 2026

Cholesterol Efflux Assay
Published on: March 6, 2012
Regulation by thyrotropin of acyl-CoA: cholesterol acyltransferase in cultured thyroid cells
Abstract:
ACAT activity measured in microsomes of thyroid cells cultured for 4 days in the presence of TSH (1 mU/ml) was two or three times lower than that of the control cells cultured for the same period in the absence of TSH. The pool of cellular cholesterol which served as the ACAT substrate, was not exchangeable with exogenous cholesterol provided in the form of liposomes. However, the incubation of microsomes with liposomes made it possible to increase the cholesterol content in the microsomes by 35%, and this resulted in the activation of ACAT activity. Nevertheless, maximum activity measured after activation in the microsomes of the control cells remained higher than that of the microsomes of cells cultured in the presence of TSH. These findings would suggest that TSH acted by diminishing the cellular content in ACAT enzyme, as well as modifying the distribution of cholesterol in the intracellular membranes.
Related Concept Videos
Regulation of Nuclear Protein Sorting
Hormones and Bone Tissue
Hormones That Influence Osteoblasts and/or Maintain the Matrix
Several hormones are necessary for controlling bone growth and maintaining the bone matrix. The pituitary gland secretes growth hormone (GH), which, as its name implies, controls bone growth. This happens in several ways: first, it triggers chondrocyte...
Skeleton and Calcium Homeostasis
Synthesis and Functions of Calcitonin
The exact mechanisms by which calcitonin operates in calcium homeostasis remain elusive, but its significance is evident in several vital...
Cholesterol: Significance and Regulation
Considering cholesterol and...
Graves Disease II: Pathophysiology

