These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: A role of melatonin in the initial stage of photoperiodism in the Japanese quail.
    Author: Ohta M, Kadota C, Konishi H.
    Journal: Biol Reprod; 1989 May; 40(5):935-41. PubMed ID: 2765617.
    Abstract:
    To estimate whether melatonin is involved in gonadal activity in the male quail, the dynamics of plasma melatonin at an early stage of the photoperiodic response were investigated. Nocturnal levels of melatonin were manipulated by treatment with anti-melatonin (anti-M). By means of 4 additional hours of photic stimulation of the brain (provided by a red light-emitting diode inserted through the back of the head) after the environmental lights (8L:16D, lights-on, 1000 h) were turned off, the elevation of levels of melatonin after lights-off was significantly suppressed on Days 1 and 2 (p less than 0.01); after 5 days of brain-lighting, gonadal growth first became noticeable. However, 4 h of brain-lighting before lights-on elicited no change in levels of melatonin or in gonadal growth. The injections of anti-M just before lights-off (at 1800 h) for the first 3 days caused significant gonadal growth (p less than 0.01), whereas injections at 2200, 0200, or 0600 h were without effect. In addition, 4 h of brain-lighting before lights-on became gonadostimulatory (p less than 0.01) when it was accompanied by the injection of anti-M at 1800 h, but remained without effect when anti-M was injected at 0600 h. These results suggest that melatonin is involved in the initial stage of photoperiodism in birds, and the timing of suppression of the elevation of melatonin levels is critical in gonadal development.
    [Abstract] [Full Text] [Related] [New Search]