d'Istria M, Monteleone P, Serino I, Chieffi G
Dipartimento di Fisiologia Umana, Integrate F. Bottazzi, Seconda Università degli Studi di Napoli, Naples, Italy.
Gen Comp Endocrinol. 1994 Oct;96(1):6-11. doi: 10.1006/gcen.1994.1153.
Day-night variations of melatonin content and N-acetyltransferase (NAT) activity were studied in the Harderian gland (HG), retina, pineal gland, and serum of the green frog Rana esculenta. Throughout the year the retinal melatonin content was correlated with retinal NAT activity and was always higher than those in the pineal gland and HG. On the other hand, in these structures diurnal fluctuations in NAT activity were observed. There were clear seasonal differences in the magnitude of the nocturnal increase of retinal melatonin levels as well as in the nocturnal pattern of retinal NAT activity. In summer day-night variations of melatonin and NAT are absent. The prevailing photoperiod seems to affect melatonin and NAT circadian rhythms in R. esculenta.
研究了食用蛙（Rana esculenta）的哈德氏腺（HG）、视网膜、松果体和血清中褪黑素含量及N-乙酰转移酶（NAT）活性的昼夜变化。全年视网膜褪黑素含量与视网膜NAT活性相关，且始终高于松果体和哈德氏腺中的含量。另一方面，在这些结构中观察到了NAT活性的昼夜波动。视网膜褪黑素水平夜间增加的幅度以及视网膜NAT活性的夜间模式存在明显的季节性差异。夏季不存在褪黑素和NAT的昼夜变化。主导光周期似乎影响食用蛙的褪黑素和NAT昼夜节律。
