[Reduced cell sensitivity to glucocorticoid hormones in hypercholesterolemia].
The number of 3H-dexamethasone binding sites in lymphocytes of subjects with hypercholesterolemia (HCS) was found to be decreased as compared to the receptor level in normolipidemic patients (N). In HCS-lymphocytes, the dexamethasone-induced inhibition of 3H-thymidine and 14C-acetate incorporation was less pronounced (by 20% and 22%, respectively) than in control cells, which is suggestive of the decreased sensitivity of HCS-lymphocytes to the hormone. An addition of 5-25% HCS blood sera to human skin fibroblast cultures caused a 10-50% decrease in the number of 3H-dexamethasone binding sites and diminished the Kd values 2-3 times. Lipid-depleted HCS-sera had no effect on the glucocorticoid reception in fibroblasts, whereas very low (VLDL) and low (LDL) density lipoproteins inhibited the 3H-dexamethasone binding to the cells. The most potent inhibiting effect was exerted by VLDL (both N-VLDL and HCS-VLDL). HCS-VLDL were more effective than N-LDL. HCS-HDL and N-HDL did not effect the 3H-dexamethasone binding to fibroblasts. In cells preincubated with VLDL dexamethasone inhibited the incorporation of 3H-thymidine and 14C-acetate less intensively (by 27% and 20%, respectively) than in control fibroblasts. The experimental results are suggestive of a decreased sensitivity of peripheral HCS-cells to glucocorticoids, which may shed some light on the mechanism of hypercholesterolemia realization into coronary heart disease and atherosclerosis.