CMPF

Furan fatty acids are unique, naturally occurring lipids that are found in significant amounts in dietary phospholipids, such as in salmon roe. [1] CMPF is an endogenous metabolite of furan fatty acids in humans. CMPF is highly albumin-bound and accumulates in the serum of uremic patients to concentrations in excess of 0.2 mM. Its primary effect is to inhibit cellular transport and subsequent deiodination of thyroxine (T4). [2] [3] CMPF is tightly bound to albumin but only moderately inhibits T4 binding in a direct manner (10-14% at 0.3 mM). However, CMPF effectively displaces competitive T4 binding molecules from albumin, such as acidic drugs and free fatty acids. [3] Therefore, CMPF may indirectly influence T4 binding to albumin by increasing the serum concentration of competitive binding molecules, particularly free fatty acids such as oleic acid.[3]

Reference:
[1]. Ishii, K., Okajima, H., Okada, Y., et al. Studies on furan fatty acids of salmon roe phospholipids. Journal of Biochemistry 103(5), 836-839 (1988).
[2]. Lim, C.F., Bernard, B.F., De Jong, M., et al. A furan fatty acid and indoxyl sulfate are the putative inhibitors of thyroxine hepatocyte transport in uremia. Journal of Clinical Endocrinology and Metabolism 76(2), 318-324 (1993).
[3]. Lim, C.F., Stockigt, J.R., Curtis, A.J., et al. A naturally occuring furan fatty acid enhances drug inhibition of thyroxine binding in serum. Metabolism 42(11), 1468-1474 (1993).