Library

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    ISSN: 1432-1238
    Keywords: Adrenaline ; Glucose ; Amino acids ; Urea ; Stable isotopes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Objective To determine the magnitude and time course of adrenergic effects on metabolism in volunteers and possible implications for the use of sympathomimetics in the critically ill. Design Descriptive laboratory investigation. Subjects 7 volunteers. Intervention Primed continuous infusions of stable isotope tracers ([15N2]-urea, [6,6-D2]-glucose, [methyl-D3]-L-leucine, [15N]-L-alanine) were used. After isotopic steady state had been reached an infusion of adrenaline (0.1 μg/kg/min) was administered (4 h). Isotopic enrichment was measured using gas chromatography-mass spectrometry and the corresponding rates of appearance were calculated. Measurements and main results Glucose production increased from 14.1±1.2 to 21.5±2.0 μmol/kg/min (p〈0.05) after 80 min of adrenergic stimulation and then decreased again to 17.9±1.2 μmol/kg/min after 240 min. Leucine and ketoisocaproate (KIC) fluxes were 2.3±0.2 and 2.6±0.2 μmol/kg/min, respectively, at baseline and gradually decreased to 1.8±0.2 and 2.2±0.1 μmol/kg/min, respectively, after 240 min of adrenaline infusion (bothp〈0.05). Alanine flux increased from 3.7±0.5 to 6.9±0.9 μmol/kg/min (p〈0.05) after 80 min of adrenergic stimulation. Urea production slightly decreased from 4.8±0.9 to 4.3±0.8 μmol/kg/min during adrenaline (p〈0.05). Conclusions Adrenaline induced an increase in glucose production lasting for longer than 240 min. The decrease in leucine and KIC flux suggests a reduction in proteolysis, which was supported by the decrease in urea production. The increase in alanine flux is therefore most likely due to an increase in de-novo synthesis. The ammonia donor for alanine synthesis in peripheral tissues and the target for ammonia after alanine deamination in the liver remain to be investigated. These results indicate that adrenaline infusion most probably will not promote already enhanced proteolysis in critically ill patients. Gluconeogenesis is an energy consuming process and an increase may deteriorate hepatic oxygen balance in patients.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    ISSN: 1432-1238
    Keywords: Noradrenaline ; Adrenaline ; Dopamine ; Oxygen consumption ; Blood pressure ; Heart rate
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Objective To determine whether noradrenaline, adrenaline and dopamine have persistent on $$\dot VO_2 $$ and metabolism. Design Descriptive laboratory investigation. Setting Laboratory of the Department of Anaesthesiology at a University Hospital. Subjects 9 volunteers. Intervention $$\dot VO_2 $$ and the plasma concentration of glucose and free fatty acids were measured prior to and during a 4 h infusion of saline (control), noradrenaline (0.14 μg/kg min) adrenaline (0.08 μg/kg min) or dopamine (7 μg/kg min),n=9 each. $$\dot VO_2 $$ was measured using an open circuit gas exchange system. Measurements and main results $$\dot VO_2 $$ increased from 250±22 ml/min to 280±38 ml/min during noradrenaline, to 298±30 ml/min during adrenaline and to 292±39 ml/min during dopamine infusion. The plasma glucose concentration increased from 6.2±0.6 mmol/l to 8.8±0.8 mmol/l, 13.2±1.4 and 7.3±0.4 mmol/l during infusion of noradrenaline, adrenaline or dopamine, respectively. The plasma free fatty acid concentration increased from 0.28±0.10 mmol/l to 0.79±0.21 mmol/l during noradrenaline and to 0.52±0.09 mmol/l during dopamine. In contrast, free fatty acid values averaged baseline values at the end of the adrenaline infusion after an initial increase to 0.72±0.31 mmol/l. Conclusions Administration of noradrenaline, adrenaline or dopamine resulted in persistent increases in $$\dot VO_2 $$ in volunteers. With the exception of the transient adrenaline effect on fatty acids the metabolic actions were steady during 4 h of adrenergic stimulation. Since the adrenergic effect on $$\dot VO_2 $$ is persistent over time a similar action in patients (e.g. septic shock) during treatment with adrenoceptor agonists may be important. Thus, an increase in $$\dot VO_2 $$ during therapy may not only reflect an oxygen debt but also a pharmacodynamic action of adrenoceptor mediated calorigenic and metabolic induction.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...