Effect of free fatty acids on the bioavailability of plasma testosterone and dihydrotestosterone

Testosterone meets albumin – the molecular mechanism of sex hormone transport by serum albumins

“…Third, the overlap of TBS1 with fatty acid binding site 6 (FA6) suggests that fatty acid levels in the blood might affect testosterone binding to SA. The presence of free fatty acids has been shown to inhibit testosterone binding to both SA and SHBG, increasing the fraction of free testosterone available for uptake by tissues 67. However, Watanabe et al 68 showed that the binding of free fatty acids to bovine serum albumin (BSA) increased the binding strength of testosterone.…”

The stimulatory effect of albumin on luteinizing hormone-stimulated Leydig cell steroid production depends on its fatty acid content and correlates with conformational changes

“…Similar effects of fatty acids have been reported in the binding properties of lipoproteins to low density lipoprotein (LDL) receptors (Bihain et al, 1989) and in the binding of steroid hormones to specific binding globulins and hormone receptors (Benassayag et al, . 1986Martin et al, 1986: Bregengord et al, 1987Nunez, 1987;Mooradian et al, 1988). Fatty acids and suramin in the concentrations used do not inhibit the N-B transition of albumin (Peters, 1985).…”

Insights into the fatty acid ester norethisterone enanthate binding to human albumin: fluorescence, circular dichroism, and docking investigations

“…42 However, the fractions of steroids that bind with high affinity to HSA are less easily available to tissues. 43 In this study, NET-AC was weaker in binding capability with HSA than NET-EN. Strong binding to HSA decreased high concentrations of free ligands released to the liver.…”