Abstract
The embryonic development of the circadian melatonin (MT) rhythm and the responsiveness of embryonic MT secretion to pituitary adenylate cyclase-activating polypeptide (PACAP) were investigated. Using dynamic in vitro bioassays, we showed the following: (1) The circadian clock and/or the intracellular signal transduction pathways connecting the clock to the MT synthesizing apparatus appear between days 16 and 18 (E16-18) of embryonic development. Lack of periodical environmental stimuli can lead to a delay in this maturation. (2) Exposure of the embryonic chicken pineal gland to PACAP induces a transitory increase in MT secretion and (3) a transitory increase in cyclic AMP efflux at or before day E13 in vitro.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
