Occurrence and Determination of a Natriuretic Hormone, 2,7,8-Trimethyl-2-(β-carboxyethyl)-6-hydroxy Chroman, in Rat Plasma, Urine, and Bile

✍ Scribed by Akihiro Hattori; Takeshi Fukushima; Kazuhiro Imai

• Publisher: Elsevier Science
• Year: 2000
• Tongue: English
• Weight: 96 KB
• Volume: 281
• Category: Article
• ISSN: 0003-2697
• DOI: 10.1006/abio.2000.4566

✦ Synopsis

The occurrence of a new natriuretic hormone, 2,7,8trimethyl-2-(␤-carboxyethyl)-6-hydroxy chroman (LLU-␣, ␥-CEHC) in rat plasma was demonstrated and its concentration was determined using a coupled-column HPLC with a fluorometric derivatization with 4-N,Ndimethylaminosulfonyl-7-piperazino-2,1,3-benzoxadiazole (DBD-PZ) followed by O-acetylation. The concentration of LLU-␣ was 328 ؎ 113 nM in rat plasma (N ‫؍‬ 5). LLU-␣ was found in not only urine, but also bile, suggesting an enterohepatic circulation in body. We also assigned the configuration at C-2 of LLU-␣ in these biological fluids as (S)-form by an HPLC with a chiral column. The LLU-␣ concentration decreased significantly by fasting for 3 days (P < 0.01). These results support the possibility that LLU-␣ is produced from ␥-tocopherol in diet via oxidative metabolism without racemization.