Possible neurotransmitter role of noradrenaline in the teleost retina.
The role of dopamine as a neurotransmitter in the retina of different species has been clearly established; however, there is still some controversy as to whether noradrenaline (NA) is present as a neurotransmitter in this tissue. In this study, we show that, under controlled conditions, NA is present in the retina of goldfish at a concentration of 0.15 +/- 0.03 ng/mg protein and its biosynthetic enzyme, dopamine beta-hydroxylase shows an activity of 2.5 +/- 0.2 pmol NA/hr/mg protein. The amount of NA increases to 1.88 +/- 0.24 ng/mg protein in light adapted animals and decreases to undetectable levels in dark adapted ones. By contrast, dopamine-beta-hydroxylase levels are not affected by changes in light conditions. This finding provides further evidence in favor of a neurotransmitter role for NA in vertebrate retina.
Laboratory Neuroquimica IVIC 21827, Caracas, Venezuela.
E H
EH
Jaffe
M
M
Urbina
B D
BD
Drujan
D000222:Adaptation, Physiological; D000818:Animals; D003624:Darkness; D004298:Dopamine / Q000378:metabolism; D004299:Dopamine beta-Hydroxylase / Q000378:metabolism; D005669:Fusaric Acid / Q000494:pharmacology; D008027:Light; D008781:Methyltyrosines / Q000494:pharmacology; D018377:Neurotransmitter Agents / Q000502:physiology*; D009638:Norepinephrine / Q000378:metabolism / Q000502:physiology*; D010507:Periodicity; D012160:Retina / Q000201:enzymology / Q000378:metabolism / Q000502:physiology*; D013997:Time Factors; D019805:alpha-Methyltyrosine
D008781:Methyltyrosines; D018377:Neurotransmitter Agents; D019805:alpha-Methyltyrosine; D004299:Dopamine beta-Hydroxylase; D005669:Fusaric Acid; D004298:Dopamine; D009638:Norepinephrine