Desynchronization and resynchronization after west-east and east-west transmeridian flight

Changes of some parameters of circadian rhythms (mesor, amplitude, acrophase) have been studied in healthy students and physicians during a double transmeridian flight : westward (Rome-Jakarta-Ambon Maluku Islands) and eastward direction (Ambon, Rome). In the present study, performed in November-December, both an acute effect of transmeridian flight on different variables particularly the rate of adaptation to local time, and a long-term effect have been studied. The following variables have been measured : 1) oral temperature (T.); 2) systolic blood pressure (S.B.P.); 3) diastolic blood pressure (D.B.P.) by automatic apparatus; 4) a memory test (M.) (a fixed number of playing cards in a fixed time); 5) eye-hand skull (E.H.S.) - the time necessary to order a fixed number of playing cards according to colour and suit; 6) fusion critical frequency (F.C.F.) of retinal vision. Measurements were performed at 4-hour intervals by autorythmometry. In conclusion it is possible to point out in this experience an asymmetry-effect in the adaptation of circadian rhythms according to the direction of flight : in the westward flight the acrophases of T, SBP and EHS approach, within 72 hrs, those previously observed before the beginning of the study, whereas in Jakarta, 24 hrs after the eastward flight the same variables maintain the same acrophases of Rome local time, within the first 24 hrs, and completely adjust to local time within ten day in Ambon.