Endres P, Roeren T K, Schönen J, Ferlinz R
Prax Klin Pneumol. 1978 Sep;32(9):613-5.
Plasma cAMP levels were measured by a competetive protein binding method in nine healthy volunteers every 30 minutes over a period of 24 hours under standardized conditions. No circadian variation was observed. Upright posture after 32 hours bedrest increased cAMP significantly.