Catecholamine biochemical studies

Identification, isolation, and removal of (polyhydroxy)benzenes from the environment have received increased attention throughout the 1980s and 1990s. The biochemical activity of the benzenepolyols is at least in part based on thek oxidation—reduction potential. Many biochemical studies of these compounds have been made, eg, of enzymic glycoside formation, enzymic hydroxylation and oxidation, biological interactions with biochemically important compounds such as the catecholamines, and humic acid formation. The range of biochemical function of these compounds and thek derivatives is not yet fully understood. 

Bennett, J. L. and Gianutsos, G. (1977) Distribution of catecholamines in immature Fasciola hepatica a histochemical and biochemical study. Int. J. Parasitol. 7 221-225. 

Shaw K, Montague W, Pallot DJ. Biochemical studies on the release of catecholamines from the rat carotid body in vitro. Biochim Biophys Acta 1989 1013 42-46. Fitzgerald RS, Shirahata M, Wang H-Y. Acetylcholine release from cal carotid bodies. Brain Res 1999 841 53-61. 

The increased force of contraction induced by NA in the heart muscle is one of the consequences which follow when the sympathetic innervation to the heart is stimulated. This response is mediated by sympathetic receptors which are classified as of the j9 type, since the effects are more potently produced by iso-prenaline. and are antagonized by -antagonist drugs but not by a-antag(mist drugs. Biochemical studies of the effects of catecholamines on the isolated perfused heart have shown that the inotropic effect is accompanied by a large rise in the intracellular concentration of cyclic AMP in the cardiac cells. Furthermore, this rise occurs very rapidly after exposure to the catecholamine, and slightly precedes the recorded inotropic effect (Fig. 14). There is an excellent correlation between the... 

DRUGS AFFECTING CATECHOLAMINE METABOLISM - Studies on catecholamine metabolism continue to dominate a major part of biochemical pharmacology. 

Indolealkylamines. GC-MS methods applied in studies of the biochemical pharmacology of indoleamines parallel work on the catecholamines. SIM assays for serotonin (5-hydroxytryptamine), 5-methoxytryptamine, JV-acetylserotonin and melatonin (5-methoxy-N-acetyltryptamine) in rat pineal and brain tissue have been described [453,469]. Pentafluoro-propionyl derivatives and structural homologue standardisation were employed with detection limits in the subpicomole range. Estimation of central indoleamine turnover in man currently depends upon metabolite determination in CSF. Ion monitoring determination of indole-3-acetic acid [454] a metabolite of tryptamine, and isotope dilution assays for 5-hydroxyindoleacetic acid (5-HIAA) [455,458] have been reported. Serotonin is converted by central monoamine oxidase to 5-HIAA and the measurement of this metabolite, formerly by fluorimetry, is of interest in patients with CNS disorders [470]. GC-MS has also contributed to the identification of N,N-dimethyltryptamine in vitro [471] and isotope dilution technique has been applied to the measurement of this metabolite in control subjects and in psychiatric patients [472]. 

Verhoeff NP, Christensen BK, Hussey D, Lee M, Papatheodorou G, Kopala L, Rui Q, Zipursky RB, Kapur S. Effects of catecholamine depletion on D2 receptor binding, mood, and attentiveness in humans a rephcation study. Pharmacol Biochem Behav 2003 74(2) 425-32. 

Although I have called this time period the biochemical era, one of the most important developments of the era was the truly seminal studies of Ahlquist using isolated tissues. He introduced the concept of a- and P-adrenergic receptors in 1948 as a result of studying the effects of catecholamines on a variety of physi-... 

The sedative effect of palmatine on locomotor activity and concentration of monoamine in rats was studied via behavioral and biochemical methods. Palmatine was shown to enhance the hypomotility induced by a-methyl-p-tyrosine, reserpine, and 5-hydroxytryptophan, but reduced the hypermotility produced by L-dopa plus benserazide and p-chlorophenylalanine. In addition, the alkaloid significantly decreased the concentration of dopamine and homovanillic acid in the cortex and the concentration of serotonin in the brain stem, but increased the concentration of 5-HT in the cortex and 5-hydroxyindole acetic acid in the brain stem. These results suggest that the sedative action associated with palmatine may be related to the decrease in catecholamine concentration in the cortex and serotonin in the brain stem, and the increase in the concentration of 5-HT in the cortex [309],... 

Findings that none of the traditionally used biochemical tests could reliably detect aU cases of pheochromocytomas led to recommendations that biochemical testing should include a combination of measurements of catecholamines and catecholamine metabolites. VMA is excreted in urine in large amounts, which makes measurement of this metabolite a simple, easy to implement, and time-honored test for diagnosis of pheochromocytomas. Numerous studies have now made it clear, however, that measurements of urinary VMA provide a relatively insensitive diagnostic test with limited value for initial testing for pheochromocytomas. Therefore the usual recommendation has been that biochemical testing should include measurements of urinary or plasma catecholamines and urinary metanephrines. 

In a search for a possible biochemical means of investigating the mode of action of LSD it was noted that the administration of this drug to animals resulted in an elevation of brain 5-HT levels and a depression of brain catecholamine levels (Barchas and Freedman, 1963 Koenig-Bersin et al., 1970). It therefore seemed of interest to study the effects of LSD on an enzyme which could utilize both NA and 5-HT as substrates since it was considered that such an enzyme could be used as a model for those central receptors with which LSD must interact in order to produce its characteristic central effects. The enzyme which was eventually selected for study in this way was the copper-containing oxidase caeruloplasmin which utilizes both NA and... 

For the parasitic nematodes putative neurotransmitters and/or neuromodulators include ACh (excitatory), y-aminobutyric acid (inhibitory), and glutamate (excitatory). Though 5-FIT and the catecholamines are indicated by immuno-cytochemical, biochemical and anatomical techniques, their precise functions as neurosignals remains to be determined. The study of neuropeptides in nematodes has revealed the strong candidacy of the family of FMRFamide-like peptides and in particular the AF peptides which have been shown to have specific physiological effects. 

Walaas, E., Walaas, O., Haavaldsen, S. and Pedersen, B., Spectrophotometric and electron-spin resonance studies of complexes of catecholamines with Cu (II) ions and the interaction of ceruloplasmin with catecholamines. Arch. Biochem. Biophys. 100, 97 (1963). 

By studying the effect of combinations of this drug with catecholamines, propranolol, and methylxanthlnes, it was shown that dlethylcarbamazlne apparently acts as an inhibitor of phosphodiesterase. Dlsodlum cromo-glycate, by contrast, could not be shown to Interact with any of the components of the cyclic AMP system, and it is therefore concluded that it must inhibit mediator release at a different step in the biochemical sequence leading to release.In fact, it has been suggested that this drug inhibits the action of the phospholipase A which has been postulated by Hdgberg and UvnSs, to be Involved in the release sequence. 

---