ERYTHROCYTE ION-TRANSPORT ALTERATIONS IN HYPERTRIGLYCERIDEMIC RATS

1. Hypertension appears to be associated with both abnormalities in io n transport and disturbances in lipid metabolism The aim of the presen t study was to search for alterations in erythrocyte ion transport in hereditary hypertriglyceridaemic rats. This strain is characterized by a pronounced elevation of blood pressure which correlates with the pl asma triacylglycerol level. 2. Erythrocyte Na+ content was elevated in hypertriglyceridaemic rats due to an increased ouabain-resistant Naf net uptake. This was caused not only by the acceleration of bumetanide -sensitive Na+ inward co-transport, but also by the augmentation of bu metanide-resistant Na+ inward leak. A moderate enhancement of bumetani de-sensitive Rbf uptake was seen in hypertriglyceridaemic animals, but there were no changes in bumetanide-resistant Rbf leak. 3. The plasma triacylglycerol level correlated positively not only with blood press ure (P<0.001) but also with ouabain-resistant Naf transport (P<0.002), bumetanide-sensitive Na+ and K+ (Bb(+)) co-transport (P<0.01 and P<0. 001, respectively), bumetanide-resistant Naf leak (P<0.02) and erythro cyte Naf content (P<0.05). 3. Thus the association of augmented ouabai n-resistant Na+ transport with elevated blood pressure in this form of experimental hypertension might be mediated by genetic disorders of l ipid metabolism.