Search Results
You are looking at 1 - 1 of 1 items for
- Author: J. F. Cockrem x
- Refine by access: All content x
Search for other papers by J. F. Cockrem in
Google Scholar
PubMed
Search for other papers by B. K. Follett in
Google Scholar
PubMed
ABSTRACT
Melatonin was measured by radioimmunoassay in homogenates of pineal glands from quail (Coturnix coturnix japonica) kept under different photoperiods and in darkness. Under 8-, 12- and 16-h daylengths melatonin levels were increased during the dark period, the duration of the increase depending on the duration of the dark period. As the daylength was increased the peak occurred closer to lights-off, reflecting the more rapid melatonin rise under the longer photoperiods. The pineal melatonin rhythm continued in darkness with an amplitude relative to that seen under a light/dark cycle of slightly less than one-half after 2 days in darkness and one-third after 6 days in darkness. The corresponding average periods of the rhythm were 25·5 h and 25·7 h. These results show that there is a circadian rhythm of melatonin in the pineal gland of the quail which is entrained by light/dark cycles and which continues in darkness.
J. Endocr. (1985) 107, 317–324
