PRINCIPAL INVESTIGATOR (S ) : P. M. Hahn, Takashi Hoshizaki, and W. Ross Adey 



EXPERIMENT TITLE/NUMBER : Circadian Rhythms of the Macaca nemestrina Monkey in 



Biosatellite III 

 PROGRAM/ MISSION : Biosatellite III 



CLASSIFICATION : Animal - Pig-tailed monkey ( Macaca nemestrina ) 



DISCIPLINE(S) : Chronobiology 



OBJECTIVES : To study the effect of weightlessness on circadian rhythms. 



PROTOCOL : Plotting techniques were used to estimate periodicity. 7.5 cycles 

 for 24-hr. periods were used. Day averaging was the most common method used. 

 Data obtained during the flight were interpolated to fixed 1.5 hour intervals. 



EQUIPMENT : On-board flight recorder, camera, magnetic tape. 



RESULTS : pC0 ? (measurement of metabolism and respiration) had a periodicity 

 of greater than 25 hours as did the subject's temperature and heart rate. The 

 blood pressure rhythms were not larger than 24 hours. The 4 control animals 

 had rhythms of 24 hours. 



CONCLUSIONS : Internal desynchronosis of temperature, cardiac and respiratory 

 cycles from the blood pressure and the external desynchronosis from the 

 imposed 24 hour daily routine may have been detrimental to the well being of 

 the flight subject. The derangement of the cardiovascular system suggested as 

 a concomitant of space flight, and the desynchronosis found in the flight 

 subject may well have acted synergistically to bring about its rapid 

 deterioration. There was no evidence of this desynchronosis in the ground 

 controls. This leads to the possibility of the existence of a gravity 

 dependent mechanism in the control of circadian rhythm. 



PUBLICATIONS : 239, 285 



109 



