Affiliations: Department of Pediatrics, Osaka Medical College,
Osaka, Japan
Note: [] Address for correspondence: Kimitaka Takitani, Department of
Pediatrics, Osaka Medical College, 2–7 Daigakumachi, Takatsuki, Osaka,
569-8686, Japan. Tel.: +81 72 683 1221; Fax: +81 72 684 6554; E-mail:
ped016@poh.osaka-med.ac.jp
Abstract: Retinol and its metabolite retinoic acid play a critical role in
immunity, reproduction, and development. Retinoids are known to influence renal
development, and show beneficial effects in experimental models of renal
disease. β-Carotene (provitamin A) is cleaved to
retinal by β-carotene 15,15'- monooxygenase (BCM),
which is an essential enzyme for retinoid biosynthesis. However, the metabolism
of retinol and β-carotene in renal diseases such as
nephrosis remains unclear. We studied BCM gene expression and retinol status in
rats with nephrotic syndrome induced by puromycin aminonucleoside (PAN). BCM gene expression in the liver and intestines of PAN-treated rats
was decreased compared with that in controls, {while the expression in the
kidney of PAN-treated animals was increased.} Plasma retinol and
retinol-binding protein levels were decreased in PAN-treated rats, but hepatic
retinol level did not differ between PAN-treated and control rats.
Up-regulation of BCM gene expression in the kidneys of rats with nephrotic
syndrome may result in increased conversion of β-carotene to retinal, so this change might supply more retinoic acid
to the damaged glomeruli. Changes in the metabolism of retinol and
β-carotene might have an important role in protection
against the development of nephrosis.
