Circadian course of delta 5,3 beta-hydroxysteroids and glucocorticosteroids in the plasma and brain of rats

Corticosterone (B), pregnenolone (P) and dehydroepiandrosterone (D) undergo circadian variations in the rat plasma and brain. When the data are interpreted by the Cosinor method, the acrophases of P in brain and of D in plasma significantly precede the acrophase of B. The asynchrony of delta 5-3 beta-hydroxysteroid and glucocorticosteroid rhythms brings an additional argument in favor of separate regulatory mechanisms.