Is the level of steroid hormones in the low density lipoprotein (LDL) particles responsible for the prostaglandin I2 inhibitory potency of LDL?
In LDL fractions, isolated by ultracentrifugation, sexual hormones are detectable. LDL from male volunteers contained a significantly higher level of testosterone than LDL from female volunteers. This difference, however, is not responsible for the enhanced ability of LDL from men versus LDL from women to inhibit PGI2 formation. The importance of LDL testosterone is contradicted by the following results: Firstly, the PGI2 inhibitory potency of LDL is independent of the age of volunteers and the recentrifugation of isolated LDL fractions, but the level of testosterone is diminished with increasing age of volunteers and after recentrifugation. Secondly, LDL from hyperlipidemic men type II a did not inhibit PGI2 formation, but the level of testosterone in the LDL of these volunteers is significantly higher than in LDL from healthy men.
D000328:Adult; D000367:Age Factors; D000368:Aged; D000818:Animals; D011464:Epoprostenol / Q000096:biosynthesis*; D004958:Estradiol / Q000032:analysis; D005260:Female; D006801:Humans; D006949:Hyperlipidemias / Q000378:metabolism; D008077:Lipoproteins, LDL / Q000032:analysis*; D008297:Male; D008861:Microsomes / Q000378:metabolism; D008875:Middle Aged; D012737:Sex Factors; D013739:Testosterone / Q000032:analysis*
D008077:Lipoproteins, LDL; D013739:Testosterone; D004958:Estradiol; D011464:Epoprostenol