Genetics of the low density lipoprotein receptor: II. Genetic control of variation in cell membrane low density lipoprotein receptor activity in cultured fibroblasts.
Fibroblast low density lipoprotein (LDL) plasma membrane receptor activity, measured as 125I-LDL association (plasma membrane binding plus intracellular accumulation) and degradation was determined in cell strains from 14 monozygotic (MZ) and 21 like-sexed dizygotic (DZ) normolipidemic twin pairs. The twins were between 57 and 62 years old and had liver apart for an average of 38 years (range 0-60). The intrapair differences were significantly smaller in MZ than in DZ twin pairs in fibroblast 125I-LDL association as well as degradation assays (P less than 0.05). These findings suggest a genetic influence on normal variation in LDL receptor activity in vitro. In two MZ pairs discordant for psoriasis, the psoriatic twin had markedly lower LDL receptor activity than the cotwin.
D002462:Cell Membrane / Q000378:metabolism; D002478:Cells, Cultured; D005260:Female; D005347:Fibroblasts / Q000378:metabolism; D014644:Genetic Variation; D006801:Humans; D008077:Lipoproteins, LDL / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D011247:Pregnancy; D011956:Receptors, Cell Surface / Q000235:genetics*; D018110:Receptors, Lipoprotein; D014427:Twins; D014429:Twins, Dizygotic; D014430:Twins, Monozygotic
D008077:Lipoproteins, LDL; D011956:Receptors, Cell Surface; D018110:Receptors, Lipoprotein