Bunazosin enhances receptor-mediated endocytosis of low-density lipoproteins.
The effects of bunazosin, an alpha 1-adrenergic receptor antagonist, on low-density lipoprotein (LDL) receptor activity have been studied in cultured cells. Human skin fibroblasts, swine aortic smooth muscle cells and a human hepatoma cell line (Hep G2) were used for this study. Bunazosinm, at a concentration of 5 x 10(-5) to 10(-4) M, increased 125I-LDL uptake with all of the cell lines and 125I-LDL degradation with human skin fibroblasts and swine aortic smooth muscle cells. However, in human skin fibroblasts pretreated with lipoprotein deficient serum and Hep G2 cells, the degradation of 125I-LDL was decreased by bunazosin. These results suggest that bunazosin increases LDL receptor activity.
Department of Internal Medicine, School of Medicine, Fukuoka University, Japan.
A
A
Matsunaga
K
K
Hidaka
J
J
Sasaki
K
K
Arakawa
D000317:Adrenergic alpha-Antagonists / Q000494:pharmacology*; D000818:Animals; D002478:Cells, Cultured; D004705:Endocytosis / Q000187:drug effects*; D006801:Humans; D007457:Iodine Radioisotopes; D008077:Lipoproteins, LDL / Q000276:immunology* / Q000378:metabolism; D011799:Quinazolines / Q000494:pharmacology*; D011973:Receptors, LDL / Q000187:drug effects*; D013552:Swine; D014407:Tumor Cells, Cultured
D000317:Adrenergic alpha-Antagonists; D007457:Iodine Radioisotopes; D008077:Lipoproteins, LDL; D011799:Quinazolines; D011973:Receptors, LDL; C018176:bunazosin