Involvement of calcium in the regulation of serotonin N-acetyltransferase in retina. J Neurochem 1986 Jan;46(1):82-8
Date
01/01/1986Pubmed ID
2415684DOI
10.1111/j.1471-4159.1986.tb12928.xScopus ID
2-s2.0-0022628515 (requires institutional sign-in at Scopus site) 41 CitationsAbstract
The possible involvement of calcium in the regulation of retinal serotonin N-acetyltransferase (NAT) activity was investigated using eye cups of Xenopus laevis cultured in defined medium. Omitting CaCl2 from the culture medium completely inhibited the dark-dependent increase of NAT activity at night. Approximately 10(-4)-10(-3) M free Ca2+ was found to be required for the maximal increase of NAT activity in the dark. Other divalent cations--Ba2+, Sr2+, and Mn2+--did not substitute for Ca2+. Antagonists of voltage-sensitive calcium channels, including nifedipine, methoxyverapamil (D600), Co2+, and Mg2+, were found to be effective inhibitors of the dark-dependent increase of retinal NAT activity. Trifluoperazine also decreased retinal NAT activity. These studies indicate that the increase of retinal NAT activity in the dark is mediated by a specific Ca2+-dependent process and that Ca2+ influx through voltage-sensitive calcium channels is involved.
Author List
Iuvone PM, Besharse JCMESH terms used to index this publication - Major topics in bold
AcetyltransferasesAnimals
Arylamine N-Acetyltransferase
Calcium
Chickens
Circadian Rhythm
Cobalt
Darkness
Gallopamil
Ion Channels
Magnesium
Melatonin
Nifedipine
Pineal Gland
Rats
Retina
Trifluoperazine
Xenopus laevis