title: Free and conjugated catecholamines in plasma and erythrocytes of normotensive and labile hypertensive subjects during exercise and recovery.
abstract: Several lines of investigation suggest an abnormal sympathetic nervous activity (SNA) in hypertension. In an attempt to better evaluate SNA in a subgroup of hypertensive patients, free and sulpho-conjugated (conjugated) catecholamines (CA) [norepine-phrine (NE) and epinephrine (E)] were measured in plasma and red blood cells (RBC) of 10 labile hypertensive subjects at rest, during dynamic exercise and during recovery. Results were compared with the levels observed in seven normotensive subjects. At a given heart rate during the first 15 min of exercise, free plasma CA and diastolic blood pressure were significantly greater in labile hypertensives. Throughout the 1 h of exercise, conjugated plasma CA increased only in labile hypertensives, while free RBC NE increased only in normotensives. During recovery, free plasma CA decreased more slowly and blood pressure remained higher in labile hypertensives. These observations indicate that the mechanisms regulating sulphoconjugation may be altered in labile hypertensives and also suggest a defect in RBC CA transport mechanisms in these subjects. It is possible that these defects could contribute to the higher CA levels observed in labile hypertensives during exercise and recovery, and that they could be linked with the slower cardiovascular recovery observed in these subjects.
mesh_terms: D000328:Adult; D001794:Blood Pressure; D004837:Epinephrine / Q000097:blood*; D004912:Erythrocytes / Q000378:metabolism*; D006339:Heart Rate; D006801:Humans; D006973:Hypertension / Q000097:blood* / Q000503:physiopathology; D009638:Norepinephrine / Q000097:blood*; D005082:Physical Exertion; D010949:Plasma / Q000378:metabolism; D012146:Rest; D013431:Sulfates / Q000097:blood
chemical_list: D013431:Sulfates; D009638:Norepinephrine; D004837:Epinephrine