Catecholamines in humans

Raggi MA, Sabbioni C, Casamenti G, Gerra G, Calonghi N, et al. 1999. Determination of catecholamines in human plasma by high-performance liquid chromatography with electrochemical detection. J Chrom B 730 201-211. 

Cosentino M, Bombelli R, Ferrari M, Marino F, Rasini E, Maestroni GJ, Conti A, Boveri M, Lecchini S, Frigo G (2000) HPLC-ED measurement of endogenous catecholamines in human immune cells and hematopoietic cell lines. Life Sci. 68 283-295. 

Musso NR, Vergassola C, Pende A, Lotti G. Yohimbine effects on blood pressure and plasma catecholamines in human hypertension. Am J Hypertens 1995 8(6) 565-71. 

Holly JM, Makiti HL. The estimation of catecholamines in human plasma. Anal Biochem 1983 128 257-74. 

Bertler A (1961) Occurrence and localization of catecholamines in human brain. Acta Physiol Scand 51 135-161... 

Figure 9.3) [44]. An analysis of identical samples confirmed that PSD with MALDI and DIOS produced fragments similar to those observed with ESI low-energy CID MS/MS, and can be used for structural elucidation. DIOS has also been successfully appHed to the identification of catecholamines in human peripheral blood lymphocytes at approximately femtomolar levels [46]. A variant of DIOS has been described by Lee et al., who utlHzed a mesoporous silicate surface for the analysis of amino acids, pharmaceuticals, and peptides [47].

Methylated Catecholamines in Human Urine Improved Gas Chromatographic Assay... 

An Improved Method for the Differential Assay of 3-0-Methylated Catecholamines in Human Urine Using Ion-Pair Extraction and Gas Chromatography Electron Capture Detection Clin. Chim. Acta 92(2) 235-240 (1979) CA 90 182510e... 

Hi-receptors in the adrenal medulla stimulates the release of the two catecholamines noradrenaline and adrenaline as well as enkephalins. In the heart, histamine produces negative inotropic effects via Hr receptor stimulation, but these are normally masked by the positive effects of H2-receptor stimulation on heart rate and force of contraction. Histamine Hi-receptors are widely distributed in human brain and highest densities are found in neocortex, hippocampus, nucleus accumbens, thalamus and posterior hypothalamus where they predominantly excite neuronal activity. Histamine Hrreceptor stimulation can also activate peripheral sensory nerve endings leading to itching and a surrounding vasodilatation ( flare ) due to an axonal reflex and the consequent release of peptide neurotransmitters from collateral nerve endings. 

Signs and symptoms of sympathetic nervous system activity are invariably found in MH. Levels of catecholamines are markedly increased in MH. Whether activation of the sympathetic nervous system is a primary or a secondary response in the syndrome has not been fully elucidated. Gronert reported that stress-induced sympathetic hyperactivity can initiate a malignant hyperthermic episode in susceptible swine without a triggering agent. Stress-induced MH in humans has been inferred because susceptible families have been shown to have an increased incidence of sudden death. Gronert s reasons that activation of the sympathetic... 

Multiple electrodes have been used to obtain selectivity in electrochemical detection. An early example involved the separation of catecholamines from human plasma using a Vydac (The Separation Group Hesperia, CA) SCX cation exchange column eluted with phosphate-EDTA.61 A sensor array using metal oxide-modified surfaces was used with flow injection to analyze multicomponent mixtures of amino acids and sugars.62 An example of the selectivity provided by a multi-electrode system is shown in Figure 2.63... 

The major circulating hormones that influence vascular smooth muscle tone are the catecholamines epinephrine and norepinephrine. These hormones are released from the adrenal medulla in response to sympathetic nervous stimulation. In humans, 80% of catecholamine secretion is epinephrine and 20% is norepinephrine. Stimulation of cy-adrenergic receptors causes vasoconstriction. The selective a,-adrenergic receptor antagonist, prazosin, is effective in management of hypertension because it causes arterial and venous smooth muscle to relax. 

In animals, the hemorrhagic effects of acrylonitrile exposure on the adrenals may be reduced by prior exposure of the animals to adrenergic blockers or chemicals that deplete the adrenal cortex of catecholamines (Silver et al. 1987 Szabo et al. 1980). It is difficult to judge whether adrenergic antagonists would have a similar protective effect in humans, because effects of acrylonitrile on the adrenal have not been described in humans. 

Chan EC, Ho PC. 2000. High-performance liquid chromatog-raphy/atmospheric pressure chemical ionization mass spec-trometric method for the analysis of catecholamines and metanephrines in human urine. Rapid Commun Mass Spectrom 14 1959. 

Approximately 30 years ago, Schildkraut postulated that noradrenaline may play a pivotal role in the aetiology of depression. Evidence in favour of this hypothesis was provided by the observation that the antihypertensive drug reserpine, which depletes both the central and peripheral vesicular stores of catecholamines such as noradrenaline, is likely to precipitate depression in patients in remission. The experimental drug alpha-methyl-paratyrosine that blocks the synthesis of noradrenaline by inhibiting the rate-limiting enzyme tyrosine hydroxylase was also shown to precipitate depression in patients during remission. While such findings are only indirect indicators that noradrenaline plays an important role in human behaviour, and may be defective in depression, more direct evidence is needed to substantiate the hypothesis. The most obvious approach would be to determine the concentration of noradrenaline and/or its major central... 

Isobutane has been found to sensitize the myocardium to epinephrine in various animal studies. Concentrations of 50,000 ppm predisposed the dog heart to cardiac arrythmias induced by catecholamines. Monkeys administered 50,000-100,000 ppm for 5 minutes via tracheal cannulation had tachycardia, arrhythmias, and myocardial depression. Cases of sudden death due to fatal cardiac arrhythmias have been reported in humans intentionally inhaling isobutane. ... 

Changes in catecholamines and 3-O-methyl metabolite concentrations in human plasma Erythropoietin in pharmaceutical products 3,4-methylenedioxymethamphetamine, 3,4-methylenedioxyamphetamine, amphetamine, and methamphetamine in rat urine Azoxystrobin, kresoxim-methyl, and trifloxystrobin fungiddes ... 

Cardiovascular Effects. Inhalation and oral studies in humans and animals have not revealed any treatment-related histopathological lesions of heart tissue, or impairment of cardiac functions, even at dose levels causing severe liver and kidney damage (Adams et al. 1952 Stewart et al. 1961 Umiker and Pearce 1953). It is possible that high-level carbon tetrachloride exposure may produce cardiac arrhythmias by sensitization of the heart to catecholamines (Reinhardt et al. 1971). Accordingly, there is some concern for cardiovascular toxicity following substantial exposure to carbon tetrachloride. 

Isoflurane, an isomer of enflurane, together with sevoflurane are the most commonly used inhalation anesthetics in humans. Isoflurane does not sensitize the myocardium to catecholamines, has muscle relaxing action so less neuromuscular blocker is required and causes less hepatotoxicity and renal toxicity than halothane. 

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