Effect of vitamin C depletion on age-related hearing loss in SMP30/GNL knockout mice.

Abstract

Using senescence marker protein 30 (SMP30)/gluconolactonase (GNL) knockout (KO) mice, which cannot synthesize vitamin C (VC), we examined whether modulating VC level affects age-related hearing loss (AHL). KO and wild-type (WT) C57BL/6 mice were given water containing 1.5 g/L VC [VC(+)] or 37.5mg/L VC [VC(-)]. At 10 months of age, KO VC(-) mice showed significant reduction in VC level in the inner ear, plasma, and liver, increase in auditory brainstem response (ABR) thresholds, and decrease in the number of spiral ganglion cells compared to WT VC(-), WT VC(+), and KO VC(+) mice. There were no differences in VC level in the inner ear, ABR thresholds, or the number of spiral ganglion cells among WT VC(-), WT VC(+), and KO VC(+) mice. These findings suggest that VC depletion can accelerate AHL but that supplementing VC may not increase VC level in the inner ear or slow AHL in mice.

• Authors: Akinori Kashio, Akiko Amano, Yoshitake Kondo, Takashi Sakamoto, Hitoshi Iwamura, Mitsuya Suzuki, Akihito Ishigami, Tatsuya Yamasoba
• Journal: Biochemical and biophysical research communications (Biochem Biophys Res Commun) Vol. 390 Issue 3 Pg. 394-8 (Dec 18 2009) ISSN: 1090-2104 [Electronic] United States
• PMID: 19733551 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Calcium-Binding Proteins
• Intracellular Signaling Peptides and Proteins
• Rgn protein, mouse
• Carboxylic Ester Hydrolases
• gluconolactonase
• Ascorbic Acid

Topics

• Aging (metabolism, pathology)
• Animals
• Ascorbic Acid (administration & dosage, biosynthesis, physiology)
• Ascorbic Acid Deficiency (genetics, metabolism, physiopathology)
• Auditory Threshold
• Calcium-Binding Proteins (genetics)
• Carboxylic Ester Hydrolases (genetics)
• Intracellular Signaling Peptides and Proteins (genetics)
• Mice
• Mice, Knockout
• Presbycusis (metabolism, pathology, physiopathology)
• Spiral Ganglion (metabolism, pathology)