Nicolau G Y
Endocrinologie. 1979 Jul-Sep;17(3):177-83.
Continuous darkness regimen applied to rats for 30 days did not significantly alter the patterns of the circadian rhythms of RNA, DNA and total protein in the thyroid and adrenals. These results show that the dominant role of light as a "Zeitgeber" cannot be generalized in the case of the biorhythms studied.