1 . Weinert D . Age‐dependent changes of the circadian system . Chronobiol Int(Abstract),2000,17.5 . Yen SS,Laughlin GA . Aging and the adrenal cor tex . Exp Gerontol,1998,33(7‐.6 . Vermenlen A . Kanfman JM . Aging of the hypo thalamo‐pituitary‐testicular ......