Maintained cerebral metabolic ratio during exercise in patients with beta-adrenergic blockade
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Maintained cerebral metabolic ratio during exercise in patients with beta-adrenergic blockade. / Gam, Christiane M B; Rasmussen, Peter; Secher, Niels H; Seifert, Thomas; Larsen, Fin S; Nielsen, Henning B; Gam, Christiane Marie Bourgin.
In: Clinical Physiology and Functional Imaging, Vol. 29, No. 6, 11.2009, p. 420-426.Research output: Contribution to journal › Journal article › Research › peer-review
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TY - JOUR
T1 - Maintained cerebral metabolic ratio during exercise in patients with beta-adrenergic blockade
AU - Gam, Christiane M B
AU - Rasmussen, Peter
AU - Secher, Niels H
AU - Seifert, Thomas
AU - Larsen, Fin S
AU - Nielsen, Henning B
AU - Gam, Christiane Marie Bourgin
PY - 2009/11
Y1 - 2009/11
N2 - BACKGROUND: Decreased cerebral metabolic ratio (CMR) [molar uptake of O(2) versus molar uptake of (glucose + (1/2) lactate)] during exercise is attenuated by intravenous administration of the non-selective beta-adrenergic receptor antagonist propranolol. We evaluated to what extent cirrhotic patients in oral treatment with propranolol are able to mobilize brain non-oxidative carbohydrate metabolism. METHODS: Incremental cycle ergometry to exhaustion (86 +/- 4.2 W; mean +/- SD) was performed in eight cirrhotic patients instrumented with a catheter in the brachial artery and one retrograde in the right internal jugular vein. Healthy subjects form the control group. RESULTS: In beta-blocked cirrhotic patients arterial lactate increased from 1.5 +/- 0.3 to 5.1 +/- 0.8 mM (P<0.05) and the arterial-jugular venous difference (a-v diff) from -0.01 +/- 0.03 to 0.30 +/- 0.05 mM (P<0.05) at rest and during exercise, respectively. During exercise the glucose a-v diff of 0.46 +/- 0.06 mM remained at a level similar to rest (0.54 +/- 0.03 mM) and at exhaustion the CMR was not significantly changed (5.8 +/- 1.1 versus 6.0 +/- 0.6). In controls, CMR decreased from 5.6 +/- 0.9 at rest to 3.4 +/- 0.7 (P<0.05) during maximal exercise and at a lactate level comparable to that achieved by the patients it was 3.8 +/- 0.4. CONCLUSION: During exhaustive exercise in cirrhotic patients the CMR is maintained and a significant cerebral uptake of lactate is demonstrated. The data suggest that oral treatment with a non-selective beta-adrenergic receptor antagonist attenuates cerebral non-oxidative metabolism Udgivelsesdato: 2009/11
AB - BACKGROUND: Decreased cerebral metabolic ratio (CMR) [molar uptake of O(2) versus molar uptake of (glucose + (1/2) lactate)] during exercise is attenuated by intravenous administration of the non-selective beta-adrenergic receptor antagonist propranolol. We evaluated to what extent cirrhotic patients in oral treatment with propranolol are able to mobilize brain non-oxidative carbohydrate metabolism. METHODS: Incremental cycle ergometry to exhaustion (86 +/- 4.2 W; mean +/- SD) was performed in eight cirrhotic patients instrumented with a catheter in the brachial artery and one retrograde in the right internal jugular vein. Healthy subjects form the control group. RESULTS: In beta-blocked cirrhotic patients arterial lactate increased from 1.5 +/- 0.3 to 5.1 +/- 0.8 mM (P<0.05) and the arterial-jugular venous difference (a-v diff) from -0.01 +/- 0.03 to 0.30 +/- 0.05 mM (P<0.05) at rest and during exercise, respectively. During exercise the glucose a-v diff of 0.46 +/- 0.06 mM remained at a level similar to rest (0.54 +/- 0.03 mM) and at exhaustion the CMR was not significantly changed (5.8 +/- 1.1 versus 6.0 +/- 0.6). In controls, CMR decreased from 5.6 +/- 0.9 at rest to 3.4 +/- 0.7 (P<0.05) during maximal exercise and at a lactate level comparable to that achieved by the patients it was 3.8 +/- 0.4. CONCLUSION: During exhaustive exercise in cirrhotic patients the CMR is maintained and a significant cerebral uptake of lactate is demonstrated. The data suggest that oral treatment with a non-selective beta-adrenergic receptor antagonist attenuates cerebral non-oxidative metabolism Udgivelsesdato: 2009/11
KW - Adrenergic beta-Antagonists
KW - Aged
KW - Brain
KW - Female
KW - Humans
KW - Liver Cirrhosis
KW - Male
KW - Middle Aged
KW - Oxygen
KW - Physical Endurance
U2 - 10.1111/j.1475-097X.2009.00889.x
DO - 10.1111/j.1475-097X.2009.00889.x
M3 - Journal article
C2 - 19659603
VL - 29
SP - 420
EP - 426
JO - Clinical Physiology and Functional Imaging
JF - Clinical Physiology and Functional Imaging
SN - 1475-0961
IS - 6
ER -
ID: 19546088