Rhesus monkey infants were raised from birth until 6 or 12 months of age on a taurine‐free soy protein based human infant formula or on the same formula supplemented with taurine. An additional group received taurine‐free formula until 6 months. The densities of rod and cone visual pigments were measured by fundus reflectometry at 6 and 12 months, and retinal morphology was then examined by light and electron microscopy. The densities of rhodopsin, measured in the near periphery after a white bleach, and of cone pigment, measured in the macula after a red bleach, were significantly reduced in the taurine deprived monkeys at 6 months but not at 12 months. The retinas of 6‐month‐old taurine‐deprived infants showed degenerative morphological changes in photoreceptors, particularly in cones in the foveal region, which were somewhat less severe than those seen in a previous study at 3 months of age. The prevalence and degree of these abnormalities continued to decrease with age in taurine‐deprived animals, but changes persisted in some animals at 12 months. Recovery was more complete in monkeys reversed to the supplemented diet from 6 to 12 months. Thus, monkey infants are dependent on dietary taurine to maintain normal retinal structure until at least 6 months of age; the effects of taurine deprivation regress spontaneously but incompletely by 12 months. © 1993 Wiley‐Liss, Inc.
- infant nutrition
- retinal degeneration
- taurine‐deprived monkeys
ASJC Scopus subject areas
- Cellular and Molecular Neuroscience