Effect of storage on plasma non-esterified fatty acid concentration Forbes and Camlinl pointed out that a steadily increasing NEFA concentration is found in serum, even when stored in the frozen state. This rise was attributed to in zlitro lipolysis of enzymatic or physico-chemical origin. The NEFA concentration was determined by the method of Dole2. As the method of Novak3 is much more specific than Dole’s procedure4,5, we re-evaluated the question, using the former method to determine the NEFA concentration. As shown in Fig. I, the plasma concentration remains unchanged for 17 days however, the NEFA concentration increases if stored at $4” and at -20’. At +20°, notably, even after 24 11.
Probably, most of the rise found by Forbes and Camlin may be attributed to titration of non-NEFA organic acids originating during storage. The heptane extracts are stable for e.t least 7 days, even if stored at $20”. Rijksuniversiteit Gent, Polikliniek VOOYInxemfige Akademisch Zickenhuis, Gent (Belgium) I A. L. FORBES .UVD J. ,\. CAMLIN, Pmt. L 3 4 5
V. M. J. J.
Ser. Ewptl. Rid. Med. 102 (1953) F’. DOLE, J. Clin. Inwst., 35 (~959) 150. Novae, ,J. Lipid Res., 6 (1965) 431. PARIJS, I‘.BARBIER AND A. ELEWAUT, Clin.Chenz., 12 (196h) 707. PARIJS, Clip!. Chim. Acta, 14 (1966) 713.
Received * Directeur
C‘lin. Chzvn. Acta,
Dr. 1~. Remouchamps. zo (1968)