Guerrero J M, Santana C, Reiter R J
Department of Cellular and Structural Biology, University of Texas Health Science Center, San Antonio 78284.
Neurosci Lett. 1988 Jun 29;89(2):229-33. doi: 10.1016/0304-3940(88)90386-2.
The effects of either isoproterenol or dibutyryl cyclic AMP on rat pineal thyroxine type-II 5'-deiodinase (5'-D) and N-acetyltransferase (NAT) activities were studied using an organ culture technique. Moving the animals to light at night dramatically inhibited the NAT with no change in the 5'-D activity. The subsequent incubation of pineal glands with either isoproterenol or dibutyryl cyclic AMP restored the NAT activity and caused a further rise in 5'-D activity. In animals maintained under light conditions during the night, both isoproterenol and dibutyryl cyclic AMP were able to stimulate the 5'-D and NAT activities. The results suggest that the beta-adrenergic activation of the 5'-D activity is mediated by cyclic AMP in the rat pineal gland.
采用器官培养技术研究了异丙肾上腺素或二丁酰环磷腺苷对大鼠松果体甲状腺素II型5'-脱碘酶(5'-D)和N-乙酰转移酶(NAT)活性的影响。夜间将动物移至光照环境会显著抑制NAT活性,而5'-D活性无变化。随后用异丙肾上腺素或二丁酰环磷腺苷孵育松果体可恢复NAT活性,并使5'-D活性进一步升高。在夜间处于光照条件下饲养的动物中,异丙肾上腺素和二丁酰环磷腺苷均能刺激5'-D和NAT活性。结果表明,大鼠松果体中5'-D活性的β-肾上腺素能激活是由环磷腺苷介导的。