PRINCIPAL INVESTIGATOR (S ): Carolyn S. Leach, and Paul C. Rambaut 



EXPERIMENT TITLE/NUMBER : Biochemical Responses of the Skylab Crewmen, M073 



PROGRAM/MISSION : Skylab 2, 3, 4 



CLASSIFICATION : Human 



DISCIPLINE(S) : Endocrinology, Environmental health 



OBJECTIVES : To assess the effect of space flight on endocrine and metabolic 

 functions including fluid and electrolyte control mechanisms. 



PROTOCOL : Metabolic monitoring began on day F-21 and continued through day 

 R+17. Blood and urine samples were collected preflight, inflight, and 

 postf light. For the blood samples, Na~ EDTA was used as an anticoagulant. 

 Radioassay, fluorometric and gas chromatographic techniques were used for most 

 hormonal analyses. Radionuclide body compartment studies were conducted 

 preflight and postflight. These^included dilution studies of„total body water 

 (tritium), extracellular. fluid (^sulphate), plasma volume ( I-protein) and 

 exchangeable potassium ( K and K). 



EQUIPMENT : Blood collection device, urine collection device. 



RESULTS : In the blood samples, elevations were found in Ca and POj. inflight 

 and remained high for several days postflight. Cortisol and angiotensin I 

 were generally elevated. K and creatinine increased inflight and remained 

 high immediately after recovery. Plasma aldosterone, total protein, carbon 

 dioxide, thyroid stimulating hormone, and thyroxine were increased postflight. 

 Reduction was noted in Na, CI, osmolality and ACTH inflight and postflight. 

 There were postflight decreases in cholesterol, uric acid, magnesium, lactic 

 dehydrogenase, and total bilirubin. BUN and albumin were unchanged at R+0, 

 but decreased R+3 and R+14. All electrolytes in the 24-hour urine samples 

 were increased inflight along with aldosterone, Cortisol, and total 

 17-ketosteroids. Postflight increases were seen in epinephrine, 

 norepinephrine, aldosterone, and Cortisol. There were trends toward inflight 

 decreases in ADH, epinephrine, norepinephrine, and uric acid. Decreases were 

 noted postflight in Na, K. CI, osmolality, PO^, magnesium, uric acid, ADH, and 

 total 17-hydroxycorticosteroids. 



CONCLUSIONS : Significant biochemical changes were observed, varying in 

 magnitude and direction, but all disappeared shortly after return to Earth. 

 These changes are an indication of successful adaptation of the body to the 

 combined stresses of weightlessness. The transient nature of some of these 

 changes, particularly in fluid and electrolyte metabolism, tend to support the 

 conclusion that a new and stable condition of homeostasis had been achieved. 



PUBLICATIONS : 293, 334, 335, 336, 337, 338, 340, 345, 346, 347, 533 



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