An automated method for determination of noradrenaline and adrenaline in tissues and biological fluids

The mechanism of acute gastric ulcer after induced hemorrhagic shock

Changes in gastric mucosal blood flow were investigated for their relationship to gastric mucosal prostaglandin E2 (PGE2) and noradrenaline (NA) in rats with hemorrhagic shock. The results were as follows: 1) Gastric mucosal blood flow and NA decreased after hemorrhage. Gastric mucosal PGE2 initially increased after exsanguination and then markedly decreased. 2) Administration of NA before hemorrhage resulted in an increase of PGE2. However, the PGE2 value for animals receiving NA after hemorrhage was not different from that of non-NA-treated group. 3) Pre-treatment with PGE2 suppressed the reduction in both gastric mucosal blood flow and NA and the development of ulcer. These results suggest that the increase in gastric mucosal PGE2 in the early stage of shock might represent a phenomenon of adaptation by the adrenergic activation, and the decrease in PGE2 in the late stage might result from impaired synthesis of PGE2 due to persistent hypoxia and might be one of the possible factors in ulcer formation.

An approach to the mechanism of acute ulceration in obstructive jaundice

Changes of noradrenaline (NA) and prostaglandin (PG) E2 in gastric mucosa and gastric wall blood flow (GWBF) were investigated after stress load in rats with obstructive jaundice. We found that water immersion and restraint stress more easily increased the ulcer index and decreased GWBF, corresponding to a decrease of the NA and PGE2 contents in the gastric mucosa, as the duration of jaundice increased. Administration of PGE2 reduced the increase of the ulcer index and the decrease of the GWBF and NA contents in the gastric mucosa. It is suspected that the rapid decrease of NA and PGE2 is connected with the rapid decrease of GWBF after stress load in obstructive jaundice, and we reached the hypothesis that both PGE2 and NA mutually regulate local GWBF.

Estimation of catecholamines in human plasma by ion-exchange chromatography coupled with fluorimetry

Estimation of catecholamines in human plasma was made by ion-exchange chromatography coupled with fluorimetry. Catecholamines in deproteinized plasma were adsorbed onto Amberlite CG-50 (pH 6.5, buffered with 0.4 M phosphate buffer) and selectively eluted by 0.66 M boric acid. The catecholamine fraction was separated further on a column of Amberlite IRC-50 which was coupled with a device for the automated performance of the trihydroxyindole method (epinephrine and norepinephrine) or the 4-aminobenzoic acid-oxidation method (dopamine). One sample could be analysed within 25 min with either method. The lower detection limits were 0.02 ng for epinephrine and dopamine, and 0.04 ng for norepinephrine. Plasma catecholamine contents of healthy adults at rest were epinephrine 0.07 +/- 0.01 ng/ml (n = 19), norepinephrine 0.27 +/- 0.03 ng/ml (n = 19) and dopamine 0.22 +/- 0.03 ng/ml (n = 26). The procedure of adsorption and elution of the plasma catecholamines by ion-exchange resin was simple, the simplicity contributing to constant recovery. The catecholamine fraction could be analysed without evaporation of the eluate. The analytical column could be used for the analysis of more than 1000 samples before excessive back-pressure developed. Our method of continuous measurement of plasma catecholamine fulfils clinical requirements.

Plasma adrenaline, noradrenaline and dopamine in man and different animal species

1. The catecholamines adrenaline (A), noradrenaline (NA) and dopamine (DA) were determined in plasma samples of man and various animal species using a highly sensitive radioenzymatic method.2. Basal values were determined under conditions producing virtually no physical or psychic stress in blood obtained through acutely inserted venous catheters in human volunteers, rabbits and cows, through chronic indwelling catheters in cats and rats, and by cubital venipuncture in trained dogs.3. Basal values (pg/ml.) for A, NA, and DA were respectively 64, 203 and 98 in man, 73, 609 and 276 in cats, 166, 392 and 216 in rabbits, 56, 152 and 91 in cows, 204, 376 and 173 in dogs, and 175, 509, and 84 in SPF rats. The NA concentrations were always higher than those of A and DA.4. Gentle handling of rats for 30 sec greatly increased the levels of all catecholamines, especially of A. Even more marked rises were observed during and up to 5 min after restraint stress.5. Blood from the trunk of decapitated rats contained about 20 times more A and 3-4 times more DA and NA than venous blood from catheters in the absence of handling.6. Basal values of plasma catecholamines in small animals can only be obtained through indwelling catheters and in the absence of handling. Most of the previously reported values are too high and are experimental artifacts.

A semi-automated measurement of urinary catecholamines using high-speed ion-exchange column chromatography

Semi-automated measurement of urinary catecholamines, specific for dopa, noradrenaline, adrenaline and dopamine and other metabolites has been developed. Steps included alumina extraction, separation by high-speed ion-exchange column chromatography and fluorescent development by trihydroxyindole (THI) method without interference by other fluorescent substances. Recovery, reproducibility and sensitivity were satisfactory. alpha-Methyldopa, a metabolite of alpha-methyldopa, and isoproterenol were separated completely without interfering with the measurement of noradrenaline, adrenaline and dopamine.