Administration of L-3,4-dihydroxyphenylalanine to rats after complete hepatectomy-II. Excretion of metabolites |
| |
Authors: | G M Tyce C A Owen |
| |
Institution: | Departments of Physiology and Biochemistry, Mayo Clinic and Mayo Foundation, Rochester, MN 55901, U.S.A. |
| |
Abstract: | The excretion of metabolites of l-3-14C]dihydroxyphenylalanine (l-3-14C]DOPA) was studied after its injection into rats with complete hepatectomies and into control rats. Approximately 60 per cent of the dose (11 mg/kg; 20 μCi) of injected 14C]DOPA was excreted in urine in 24 hr by the control rats, and 11 per cent in bile. Although a similar percentage of the dose (69.4 per cent) was excreted by the hepatectomized rats into urine, excretion was at a slower rate. Decarboxylation of injected 14C]DOPA within 24 hr appeared to be as great in the hepatectomized rats as in the controls, but metabolism of 3,4-dihydroxyphenylethylamine (dopamine, DA) to norepinephrine was less. In the operated animals most of the DA was metabolized to 3,4-dihydroxyphenylacetic acid or to homovanillic acid. Little radioactivity was present in tissues at 24 hr after injection of l-DOPA into control rats or into hepatectomized rats; however, some radioactivity appeared to be bound to protein in some tissues in both groups of rats. |
| |
Keywords: | Reprint address: Dr G M Tyce Departments of Physiology and Biochemistry Mayo Clinic Rochester MN 55901 U S A |
本文献已被 ScienceDirect 等数据库收录! |
|