Brett G Jeffrey1, Martha Neuringer. 1. Oregon National Primate Research Center and Casey Eye Institute, Oregon Health and Science University, Portland, Oregon 97006, USA. jeffreyb@ohsu.edu
Abstract
PURPOSE: Docosahexaenoic acid (DHA), an n-3 fatty acid, is the major polyunsaturate in rod outer segments. The effect of long-term n-3 fatty acid deficiency on rod and cone phototransduction was investigated in the rhesus monkey. METHODS: From birth to approximately = 9 years rhesus monkeys were fed an n-3-deficient diet (n = 9) known to reduce retinal DHA by 80%. Monkeys in the control group (n = 12) received either 8% alpha-linolenic acid (ALA) or 0.6% DHA, both of which support normal retinal DHA levels. None of the diets contained carotenoids. Photoactivation kinetics were assessed from the rate of increase and a P3 model fit of the ERG a-wave. Maximal cone amplitude and sensitivity were measured from the cone a-wave at 4 ms. The rod photoresponse and rod recovery were derived by using a paired flash RESULTS: Rod sensitivity was reduced by 40% in the n-3-deficient monkeys at 9 but not 4.5 years. The onset of the rising phase of the photoresponse was significantly delayed (P < 0.004) at 9 years. Rod recovery was delayed by 20% in n-3-deficient monkeys at both ages, but only for bright saturating flashes. Cone phototransduction was not altered by n-3 deficiency. CONCLUSIONS: Long-term dietary n-3 deficiency in the rhesus monkey was associated with two changes in retinal function. First, there was a delay in rod recovery that has remained relatively constant throughout life. Second, there was an age-dependent loss in rod phototransduction sensitivity; the lack of dietary carotenoids may have contributed to this decline.
PURPOSE:Docosahexaenoic acid (DHA), an n-3 fatty acid, is the major polyunsaturate in rod outer segments. The effect of long-term n-3 fatty acid deficiency on rod and cone phototransduction was investigated in the rhesus monkey. METHODS: From birth to approximately = 9 years rhesus monkeys were fed an n-3-deficient diet (n = 9) known to reduce retinal DHA by 80%. Monkeys in the control group (n = 12) received either 8% alpha-linolenic acid (ALA) or 0.6% DHA, both of which support normal retinal DHA levels. None of the diets contained carotenoids. Photoactivation kinetics were assessed from the rate of increase and a P3 model fit of the ERG a-wave. Maximal cone amplitude and sensitivity were measured from the cone a-wave at 4 ms. The rod photoresponse and rod recovery were derived by using a paired flash RESULTS: Rod sensitivity was reduced by 40% in the n-3-deficient monkeys at 9 but not 4.5 years. The onset of the rising phase of the photoresponse was significantly delayed (P < 0.004) at 9 years. Rod recovery was delayed by 20% in n-3-deficient monkeys at both ages, but only for bright saturating flashes. Cone phototransduction was not altered by n-3 deficiency. CONCLUSIONS: Long-term dietary n-3 deficiency in the rhesus monkey was associated with two changes in retinal function. First, there was a delay in rod recovery that has remained relatively constant throughout life. Second, there was an age-dependent loss in rod phototransduction sensitivity; the lack of dietary carotenoids may have contributed to this decline.
Authors: Valentin M Sluch; Angela Banks; Hui Li; Maura A Crowley; Vanessa Davis; Chuanxi Xiang; Junzheng Yang; John T Demirs; Joanna Vrouvlianis; Barrett Leehy; Shawn Hanks; Alexandra M Hyman; Jorge Aranda; Bo Chang; Chad E Bigelow; Dennis S Rice Journal: Sci Rep Date: 2018-09-25 Impact factor: 4.379