title: Chronobiologic lead study cost-effectively assesses circadian-circaseptan intermodulation in murine pineal melatonin content.
abstract: The investment into the design of a study is usually and unfortunately proportional to the available information, i.e. the less one knows the more one is tempted to skimp and perform a minimal 'pilot' study. This is particularly true with respect to chronobiology. On the contrary, at the outset of a study, when the information available regarding a given problem is minimal or zero, the investment into a first study should be near-maximal. Accordingly, the often wasted 'pilot study' should be replaced by a rigorous chronobiologic lead study. The promise of such a chronobiologic 'guide, leading along a difficult or unknown course' is illustrated by the validation with statistical significance of an about-weekly (circaseptan) and an about 24-h (circadian) rhythm in the melatonin content of the murine pineal. Work around the clock on 48 female Lewis/S rats was avoided. Replication of 6 different circadian times on different comparable animals on consecutive days assessed a circaseptan rhythm more prominent than the concomitantly demonstrated circadian, at no added cost for experimental animals beyond those often used for circadian study and with no work around the clock.
mesh_terms: D000818:Animals; D002909:Chronobiology Phenomena; D002940:Circadian Rhythm; D003365:Costs and Cost Analysis; D005260:Female; D008550:Melatonin / Q000032:analysis* / Q000378:metabolism; D010865:Pilot Projects; D010870:Pineal Gland / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains
chemical_list: D008550:Melatonin