Volume fraction and ultrastructure of age pigment in the saccular epithelium of old mice.
Age pigment in the sensory and supporting cells was a prominent characteristic distinguishing old saccules from young. However, the pigment was not distributed uniformly throughout the sensory epithelium but displayed cell-specific patterns of accumulation. The highest cytoplasmic volume density was in the old supporting cells followed by type I hair cells and then type II hair cells. The most common form of pigmented inclusion seen in old type I hair cells was a cluster of granules resembling melanin. This form was never seen in type II hair cells or supporting cells where a form containing a lipid-like droplet was prevalent. The differences in the amount of age pigment and the forms accumulated probably reflects metabolic differences between the three cell types.
Hubel
S B
SB
Department of Biological Sciences, Florida Institute of Technology, Melbourne 32901-6988.
Park
J C
JC
D000375:Aging; D000818:Animals; D003593:Cytoplasm / Q000032:analysis / Q000648:ultrastructure; D004848:Epithelium / Q000032:analysis / Q000648:ultrastructure; D005260:Female; D006198:Hair Cells, Auditory / Q000032:analysis / Q000648:ultrastructure; D002479:Inclusion Bodies / Q000032:analysis / Q000648:ultrastructure; D051379:Mice; D008810:Mice, Inbred C57BL; D008854:Microscopy, Electron; D010860:Pigments, Biological / Q000032:analysis*; D012444:Saccule and Utricle / Q000032:analysis* / Q000648:ultrastructure
D010860:Pigments, Biological