added reference

content/target_fatty-acid.html

@@ -21,6 +21,7 @@ interstitial space, and <a href="./target_fatty-acid-binding-protein.html">fatty
 acid binding proteins (FABPs)</a> inside the cells. 
 In the blood, albumin is the main transport protein for fatty acids,
 containing at least six binding sites for FAs. 
+The unbound free fatty acids in the plasma are excreted in urine.
 Fatty acids can readily be transported across plasma membranes because of their
 lipophilicity, but concentration is small in spaces devoid of FA binding 
 proteins, such as inside <a href="./input_rbc.html">red blood cells</a>.
@@ -169,6 +170,9 @@ Measurement of long-chain fatty acid uptake into adipocytes.
 regulators of lipid metabolism: implications for metabolic disease.
 <em>Physiol Rev.</em> 2010; 90: 367-417.</p>
 
+<p>Hagenfeldt L. Renal excretion of free fatty acids.
+<em>Clin Chim Acta</em> 1971; 32: 471-474.</p>
+
 <p>Lopaschuk GD, Ussher JR, Folmes CDL, Jaswal JS, Stanley WC. 
 Myocardial fatty acid metabolism in health and disease.
 <em>Physiol Rev.</em> 2010; 90: 207-258.</p>