[Studies on the function of fatty acid binding protein in hypertensive rat kidney].
Fatty acid binding protein was purified from renal medulla, and its binding activity and fatty acid composition were determined in spontaneously hypertensive stroke-prone rats. Wistar-Kyoto rats were used as controls. Fatty acid binding activity was higher in 5-week-old prehypertensive spontaneously hypertensive stroke-prone rats (0.155 +/- 0.006 mol palmitic acid/mol protein) as compared with control values in Wistar-Kyoto rats (0.030 +/- 0.001). However, in 40-week-old rats, the activity was decreased only in spontaneously hypertensive stroke-prone rats with established hypertension (0.035 +/- 0.002), and it did not decrease in Wistar-Kyoto rats (0.028 +/- 0.003). Fatty acid compositions were similar among 5 and 40-week-old control rats and 5-week-old hypertensive rats (palmitic acid 24%, stearic acid 14%, oleic acid 30%, linoleic acid 29%, arachidonic acid 3%), although the total amount of bound long-chain fatty acids was decreased in 5-week-old hypertensive rats, explaining the high fatty acid binding activity in this preparation. Fatty acid binding protein from 40-week-old hypertensive rats had an elevated proportion of endogenous arachidonic acid, with other fatty acids being relatively reduced (palmitic acid 8%, stearic acid 2%, oleic acid 4%, linoleic acid 10%, arachidonic acid 76%), indicating increased arachidonic acid transport in the cytosol. These results show that genetically hypertensive rats had an alteration in fatty acid transport mediated by fatty acid binding protein; this alteration may be involved in the pathogenesis of hypertension.
Department of Cardiovascular Medicine, Hokkaido University School of Medicine, Sapporo, Japan.
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Fujii
D000818:Animals; D002352:Carrier Proteins / Q000302:isolation & purification / Q000502:physiology*; D000071438:Fatty Acid-Binding Protein 7; D050556:Fatty Acid-Binding Proteins; D005227:Fatty Acids / Q000032:analysis; D006973:Hypertension / Q000378:metabolism*; D007668:Kidney / Q000378:metabolism*; D007679:Kidney Medulla / Q000378:metabolism; D008099:Liver / Q000378:metabolism; D009363:Neoplasm Proteins; D009419:Nerve Tissue Proteins; D051381:Rats; D011918:Rats, Inbred SHR; D011921:Rats, Inbred WKY
D002352:Carrier Proteins; C490174:Fabp7 protein, rat; D000071438:Fatty Acid-Binding Protein 7; D050556:Fatty Acid-Binding Proteins; D005227:Fatty Acids; D009363:Neoplasm Proteins; D009419:Nerve Tissue Proteins