ISSN:
0003-276X
Keywords:
Life and Medical Sciences
;
Cell & Developmental Biology
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Medicine
Notes:
The effect of continuous darkness on diurnal variation of glycogen content in pineal cells of adult mice was investigated by means of a semiquantitative histochemical method. In dark-maintained mice, a diurnal rhythm in pineal glycogen content persisted for the first 7 days of darkness. After 14 days or longer of continuous darkness, however, a clear relationship between the glycogen content and time of day became less apparent. Reversed conditions of environmental lighting caused a complete reversal of the glycogen rhythm in the pineal as early as the fifth day. When mice that had been kept in reversed conditions of lighting for 7 days were exposed to continuous darkness, the reversed glycogen rhythm also persisted in darkness of 7 and 14 days, but it was abolished by darkness of 28 days. The nuclear density of pineal cells was significantly lower at 9 am than at 9 pm in controls. In dark-maintained mice, however, no significant diurnal variation in pineal cell size was generally evident except 2 and 3 days after the initiation of darkness.
Additional Material:
2 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/ar.1091790310
