A comparison of the lipolytic and anticoagulative properties of heparin and pentosan polysulphate in the thoroughbred horse

Abstract

The aim of the study was to develop a model for the pre-exercise elevation of plasma free fatty acids in the horse. with a view to its future use in investigations of fat metabolism during exercise. A comparison of the lipase releasing and anticoagulative effects of heparin and a related substance pentosan polysulphate was investigated. Furthermore, the ability of heparin and pentosan polysulphate to affect an increase in plasma free fatty acid concentration, when coadministered with a triglyceride emulsion, was quantified. Doses of 0.39 and 1.3 mg kg-1 body wt of heparin and pentosan polysulphate respectively, administered intravenously, resulted in a significant increase in plasma total lipase activity (P < 0.001). There was, however, no significant difference in plasma lipase activity between treatments. Heparin resulted in a mean 14 ± 6.5-fold increase in activated partial thromboplastin time compared with a mean 1.6 ± 0.1 fold increase with pentosan polysulphate. Both heparin and pentosan polysulphate when co-administered with a triglyceride emulsion (Iverlip 20) resulted in a significant increase in plasma free fatty acid concentration (P < 0.001), although there was no significant difference between treatments. Thus, whereas a higher dose of pentosan polysulphate elicited a comparable lipolytic effect to heparin, including significant elevation of plasma free fatty acids, this was associated with a much reduced effect upon clotting function. Pentosan polysulphate. therefore, represents a suitable alternative to heparin for the elevation of plasma free fatty acids before exercise when used in conjunction with a triglyceride emulsion.