Hyperlipoproteinaemia in ponies: Mechanisms and response to therapy

1. (I) The lipid and lipoprotein concentrations in sera of 4 healthy and 9 hyperlipaemic patients were determined. From the results of the analyses, it is suggested that three types of hyperlipoproteinaemia can be distinguished in ponies: 1.1. (a) Type 1, characterised by a very pronounced increase in only the very low density lipoproteins (VLDL); 1.2. (b) Type 2, in which there is a pronounced increase in the chylomicrons (Chylo) and the very low density lipoproteins (VLDL); 1.3. (c) Type 3, which can be the result of fasting and is characterised by a moderate increase in the concentration of chylomicrons and a greater increase in very low density lipoproteins. It is suggested that hyperlipoproteinaemia in ponies can be classified on the basis of electrophoretic patterns. 2. (II) To gather more information on the metabolism of extra offered lipids, blood from ponies suffering from two different types of hyperlipoproteinaemia was transfused into normal ponies and the changes in lipid and lipoprotein concentrations in the blood serum were followed. The reactions were different. When heparin was used as anticoagulant a great increase in chylomicrons and a significant increase in very low density lipoproteins in a healthy pony was observed. When sodium citrate was used as anticoagulant a clear increase in the VLDL fraction only was noticed. Abbreviations: Lipoproteins; LP, lipoproteins; Chylo, chylomicrons; VLDL, very low density LIPOPROTEINS = pre-ß-lipoproteins; LDL, low density LIPOPROTEINS = ß-lipoproteins; HDL, high density LIPOPROTEINS = α-lipoproteins; Lipids; TL, total lipids; tot C, total cholesterol (= CE/1.7 + C); PL, phospholipids; C, free cholesterol; CE, cholesterylesters; TG, triglycerides; DG, diglycerides; FFA, free fatty acid