13C and 1H NMR study of the metabolic degradation of 4-pentenoate in different dog nephron segments.

The metabolism of 4-pentenoate in isolated kidney tubules has been investigated by 1H and 13C NMR. The 4-pentenoate metabolite, 3-keto-4-pentenoyl-CoA, accumulated in proximal tubules only and its formation could be competitively inhibited by octanoate. 4-Pentenoate was metabolized in thick ascending limbs but not in papillary collecting ducts.