[Changes in various metabolic parameters following bloodletting].
OBJECTIVE
We investigated hypovolaemia induced by bloodletting, accompanied by statistically significant, but clinically irrelevant increase of heart rate together with unchanged blood pressure, with regard to hepatic glucose production as well as alanine and glycerol turnover rates.


METHODS
Healthy male volunteers (n = 18) were bled 15 ml/kg body weight over 20 min and remained hypovolaemic for 60 minutes. Heart rate was recorded by ECG and blood pressure by an oscillometric device. Before and after bloodletting hepatic glucose production as well as alanine and glycerol turnover rates were determined using the stable isotopes 6.6-D2-glucose, 15N-alanine and D5-glycerol as tracers. Simultaneously, the blood concentrations of adrenaline, noradrenaline, free fatty acids and glycerol were measured.


RESULTS
Bleeding did not change the mean arterial blood pressure, but increased the heart rate significantly from 61 +/- 9 to 70 +/- 13 1/ min. Noradrenaline levels increased significantly from 1.16 +/- 0.41 to 2.15 +/- 0.69 nmol/l. Hepatic glucose production (HGP) as well as alanine (AlaTO) and glycerol turnover (GlyTO) decreased significantly during hypovolaemia. HGP fell from 2.72 +/- 0.29 to 2.56 +/- 0.28 mg/kg/min, AlaTO from 0.71 +/- 0.27 to 0.53 +/- 0.25 mg/kg/min and GlyTO from 4.9 +/- 2.1 to 3.8 +/- 1.4 mumol/kg/min, respectively. The blood levels of adrenaline, free fatty acids and glycerol did not change during the study.


CONCLUSIONS
In respect of clinical signs, the cardiovascular status of the volunteers was stable after bleeding. In contrast, the decrease of HGP as well as the drop in alanine and glycerol turnover rates might be interpreted as a sign of an altered functional status of single organs, induced by changes of regional perfusion.
Schütz
W
W
Universitätsklinik für Anästhesiologie, Ulm.
Schricker
T
T
Träger
K
K
Georgieff
M
M
D000328:Adult; D000409:Alanine / Q000097:blood; D001786:Blood Glucose / Q000378:metabolism; D001794:Blood Pressure / Q000502:physiology; D001810:Blood Volume / Q000502:physiology*; D004734:Energy Metabolism / Q000502:physiology*; D005990:Glycerol / Q000097:blood; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D008099:Liver / Q000378:metabolism; D008297:Male; D018962:Phlebotomy
D001786:Blood Glucose; D000409:Alanine; D005990:Glycerol
Veränderungen verschiedener Stoffwechselumsätze nach Aderlass.