TY - JOUR
T1 - The noradrenaline plasma concentration and its gradient across the lung
AU - Marenzi, G.
AU - Agostoni, P.
AU - Guazzi, M.
AU - Lauri, G.
AU - Assanelli, E.
AU - Guazzi, M. D.
PY - 2000
Y1 - 2000
N2 - Background. We investigated the lung contribution to circulating noradrenaline (NA) homeostasis. Evaluation of the transpulmonary NA gradient, related to the NA amount entering the lungs, is potentially important, mainly regarding clinical conditions, such as congestive heart failure (CHF), that are associated with excessive circulating NA. Materials and methods. 15 moderate (group 1) and 15 severe (group 2) CHF patients, and 10 normal individuals had determination of NA transpulmonary gradient in the baseline and during rise (exercise, in normals and group 1) or fall (withdrawal from plasma by ultrafiltration, in group 2) of plasma NA. Results. NA gradient (pg mL-1) at rest was 30 ± 3 in normals, 21 ± 6 in group 1 and 5 ± 8 in group 2. Increase of NA concentration in the mixed venous blood with exercise was paralleled by depression of the transpulmonary gradient. Pulmonary arteriovenous difference disappeared when NA entering the lungs averaged 1300 pg mL-1. In group 2, ultrafiltration lowered NA in the mixed venous blood from 1225 ± 213 to 718 ± 182, which caused transpulmonary gradient to increase from 5 ± 8 to 22 ± 9. Conclusions. Transpulmonary gradient of NA diminishes when NA entering the lungs increases, and 1300 pg mL-1 in the pulmonary artery is, both in patients and normal subjects, the level at which gradient disappears; which likely reflects cessation of NA uptake or achievement of a balance between lung uptake and production. This may have physiological and pathological implications.
AB - Background. We investigated the lung contribution to circulating noradrenaline (NA) homeostasis. Evaluation of the transpulmonary NA gradient, related to the NA amount entering the lungs, is potentially important, mainly regarding clinical conditions, such as congestive heart failure (CHF), that are associated with excessive circulating NA. Materials and methods. 15 moderate (group 1) and 15 severe (group 2) CHF patients, and 10 normal individuals had determination of NA transpulmonary gradient in the baseline and during rise (exercise, in normals and group 1) or fall (withdrawal from plasma by ultrafiltration, in group 2) of plasma NA. Results. NA gradient (pg mL-1) at rest was 30 ± 3 in normals, 21 ± 6 in group 1 and 5 ± 8 in group 2. Increase of NA concentration in the mixed venous blood with exercise was paralleled by depression of the transpulmonary gradient. Pulmonary arteriovenous difference disappeared when NA entering the lungs averaged 1300 pg mL-1. In group 2, ultrafiltration lowered NA in the mixed venous blood from 1225 ± 213 to 718 ± 182, which caused transpulmonary gradient to increase from 5 ± 8 to 22 ± 9. Conclusions. Transpulmonary gradient of NA diminishes when NA entering the lungs increases, and 1300 pg mL-1 in the pulmonary artery is, both in patients and normal subjects, the level at which gradient disappears; which likely reflects cessation of NA uptake or achievement of a balance between lung uptake and production. This may have physiological and pathological implications.
KW - Autonomic nervous system
KW - Heart failure
KW - Noradrenaline
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U2 - 10.1046/j.1365-2362.2000.00694.x
DO - 10.1046/j.1365-2362.2000.00694.x
M3 - Article
C2 - 10964157
AN - SCOPUS:0033852936
VL - 30
SP - 660
EP - 667
JO - European Journal of Clinical Investigation
JF - European Journal of Clinical Investigation
SN - 0014-2972
IS - 8
ER -