Continuous infusion of tracer norepinephrine may miscalculate unidirectional nerve uptake of norepinephrine in humans
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Continuous infusion of tracer norepinephrine may miscalculate unidirectional nerve uptake of norepinephrine in humans. / Henriksen, Jens Henrik Sahl; Christensen, N J; Ring-Larsen, H.
I: Circulation Research, Bind 65, Nr. 2, 1989, s. 388-95.Publikation: Bidrag til tidsskrift › Tidsskriftartikel › Forskning › fagfællebedømt
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TY - JOUR
T1 - Continuous infusion of tracer norepinephrine may miscalculate unidirectional nerve uptake of norepinephrine in humans
AU - Henriksen, Jens Henrik Sahl
AU - Christensen, N J
AU - Ring-Larsen, H
N1 - Keywords: Adult; Aged; Aged, 80 and over; Female; Humans; Infusions, Intravenous; Kinetics; Liver Cirrhosis; Male; Middle Aged; Norepinephrine; Reference Values; Sympathetic Nervous System; Tissue Distribution; Tritium
PY - 1989
Y1 - 1989
N2 - In order to evaluate uptake kinetics of norepinephrine (NE) in different tissues, a catheterization study was performed in control subjects (n = 6) and patients with enhanced sympathetic nervous activity (cirrhosis, n = 12) during constant intravenous infusion of L[3H]norepinephrine ([3H]NE) for 75 minutes. In spite of a higher NE spillover from kidneys in patients compared with controls (82 vs. 49 ng/min, p less than 0.01), renal extraction ratios of [3H]NE were similar in the two groups (0.33 vs. 0.32, NS), and no significant change was observed during the time of infusion. In contrast, liver-intestine extraction ratios of [3H]NE decreased significantly and equally with infusion time in patients (from 0.57 to 0.44, p less than 0.01) and controls (from 0.59 to 0.46, p less than 0.01). This was observed despite the fact that spillover of NE from this vascular bed was observed only in patients with cirrhosis and not in controls (41 vs. -5 ng/min, p less than 0.02). In the lower limb, net release of NE was similar in patients and controls, and extraction ratios of [3H]NE decreased almost equally with infusion time (from 0.35 to 0.30, p less than 0.01 and from 0.40 to 0.24, p less than 0.1, respectively). Whole-body clearance of [3H]NE decreased over time in patients (-6%, p less than 0.01) and controls (-20%, p less than 0.01), but significant difference was not observed between the groups. We conclude that failure to attain a steady state with respect to [3H]NE removal was demonstrated in areas of large tissue volume relative to blood flow.(ABSTRACT TRUNCATED AT 250 WORDS)
AB - In order to evaluate uptake kinetics of norepinephrine (NE) in different tissues, a catheterization study was performed in control subjects (n = 6) and patients with enhanced sympathetic nervous activity (cirrhosis, n = 12) during constant intravenous infusion of L[3H]norepinephrine ([3H]NE) for 75 minutes. In spite of a higher NE spillover from kidneys in patients compared with controls (82 vs. 49 ng/min, p less than 0.01), renal extraction ratios of [3H]NE were similar in the two groups (0.33 vs. 0.32, NS), and no significant change was observed during the time of infusion. In contrast, liver-intestine extraction ratios of [3H]NE decreased significantly and equally with infusion time in patients (from 0.57 to 0.44, p less than 0.01) and controls (from 0.59 to 0.46, p less than 0.01). This was observed despite the fact that spillover of NE from this vascular bed was observed only in patients with cirrhosis and not in controls (41 vs. -5 ng/min, p less than 0.02). In the lower limb, net release of NE was similar in patients and controls, and extraction ratios of [3H]NE decreased almost equally with infusion time (from 0.35 to 0.30, p less than 0.01 and from 0.40 to 0.24, p less than 0.1, respectively). Whole-body clearance of [3H]NE decreased over time in patients (-6%, p less than 0.01) and controls (-20%, p less than 0.01), but significant difference was not observed between the groups. We conclude that failure to attain a steady state with respect to [3H]NE removal was demonstrated in areas of large tissue volume relative to blood flow.(ABSTRACT TRUNCATED AT 250 WORDS)
M3 - Journal article
C2 - 2752547
VL - 65
SP - 388
EP - 395
JO - Circulation Research
JF - Circulation Research
SN - 0009-7330
IS - 2
ER -
ID: 18692589