Plasma [3H]noradrenaline kinetics in man: is separation of alumina extracts by high performance liquid chromatography necessary?
1. After an 80 min intravenous infusion of 1-[3H]noradrenaline ([3H]NA) in 19 subjects, the proportion of alumina-extractable 3H due to [3H]NA was 86 +/- 2% in arterial and 78 +/- 2% in venous plasma. [3H]Dihydroxy-phenylethyleneglycol ([3H]DHPG) accounted for 8 +/- 1% in arterial and 13 +/- 1% in venous plasma. [3H]Dihydroxymandelic acid ([3H]DOMA) was not detected. 2. No time-dependent change in the proportion of alumina-extractable 3H due to [3H]NA was seen in either arterial or venous plasma over this period. In venous plasma the proportion of alumina-extractable 3H due to [3H]DHPG increased slightly between 30 and 80 min, from 10 +/- 1% to 13 +/- 1%. 3. The results were unchanged with chronic beta-blockade and with either 1-[2,5,6-3H]NA or 1-[7,8-3H]NA. 4. After [3H]NA infusion in man the radioactivity recovered after alumina extraction is predominantly [3H]NA and thus can be used directly to determine [3H]NA kinetics without the need for metabolite separation.
McCance
A J
AJ
Department of Cardiovascular Medicine, John Radcliffe Hospital, Oxford, UK.
Forfar
J C
JC
D000328:Adult; D000368:Aged; D000537:Aluminum Oxide; D002851:Chromatography, High Pressure Liquid; D006801:Humans; D007262:Infusions, Intravenous; D008297:Male; D008333:Mandelic Acids / Q000097:blood; D008734:Methoxyhydroxyphenylglycol / Q000031:analogs & derivatives / Q000097:blood; D008875:Middle Aged; D009638:Norepinephrine / Q000097:blood* / Q000302:isolation & purification / Q000493:pharmacokinetics
D008333:Mandelic Acids; D008734:Methoxyhydroxyphenylglycol; C000989:3,4-dihydroxymandelic acid; D000537:Aluminum Oxide; C010117:3,4-dihydroxyphenylglycol; D009638:Norepinephrine