Catecholamines


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Catecholamines

 

pyrocatechin derivatives that participate in physiological and biochemical processes in animals and man. The catecholamines include epinephrine, norepinephrine, and dopamine.

Being hormones from the medullary layer of the adrenals and mediators of the nervous system, catecholamines reflect and determine the condition of the sympathetic division of the autonomic nervous system. They play an important role in neurohumoral regulation and neurotrophic functions and take part in the body’s metabolism and adaptive reactions to ensure the constancy of the internal environment and physiological functions (homeostasis). The effects of the catecholamines are the result of their reaction with adrenoreceptors, reactive cellular systems that react specifically with catecholamines. The a-adrenoreceptors are associated mainly with excitation; the /3-adrenoreceptors, with the inhibition of smooth muscles and with the acceleration and intensification of cardiac contractions. Catecholamines are present in blood, organs, tissues, and urine. During physical and mental exertion and in certain diseases (for example, in tumors of the adrenal medulla), the catecholamine content of the blood and urine increases sharply. Catecholamines undergo metabolic conversions (oxidative deamination, O-meth-ylation, quinoid oxidation) that lead to their inactivation or alter their physiological and biochemical properties. When functioning as mediators, the catecholamines are deposited in special granules at the nerve endings.

A number of pharmaceutical agents act on the different stages of catecholamine synthesis, release, deposition, and metabolism. For example, reserpine depletes the catecholamine reserve; par-gyline and iproniazid suppress the oxidative deamination, and Aldomet the synthesis and deposition, of catecholamines; and guanethidine and bretylium prevent the transmission of nervous impulses. These substances are used to intensify or to moderate the activity of the sympathetic nervous system.

REFERENCES

Adrenalin i noradrenalin. (Conference reports). Moscow, 1964.
Matlina, E. Sh., and V. V. Men’shikov. Klinicheskaia biokhimiia kate kholaminov. Moscow, 1967.
Manukhin, B. N. Fiziologiia adrenoretseptorov. Moscow, 1968.

G. N. KASSIL’ and E. SH. MATLINA

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Cardiac rhythm disturbances and the release of catecholamines after acute coronary occlusion in dogs.
Circulating catecholamines and complete alphaadrenergic blockade lead to tachycardia for the treatment of which the patient was started on oral propranolol 10 mg twice daily four days prior to surgery.
Fortunately, this missed pheochromocytoma diagnosis had no other clinical consequences than the late diagnosis of a large mass, since the tumor was not producing catecholamines.
5 They are further subcategorized as functional or non-functional based on their ability to synthesize and release catecholamines in the circulation.
Urinary catecholamines and cortisol levels have been measured to evaluate the effects of socioeconomic and psychosocial factors on the risk for atherosclerosis (Castro-Diehl 2014).
It also reduces the release of catecholamines from the adrenal medulla and in nerve endings and directly blocks their receptors.
This increase in motility has also been observed by other researchers when evaluating the use of catecholamines and conditioned medium in relation to Salmonella and other microorganisms (BEARSON & BEARSON, 2008; SPERANDIO et al.
No research has been found that surveyed the effect of programmed endurance exercise, with different overloading patterns, on central blood (left ventricular) catecholamines.
Note that in the present case, the tumor was detected incidentally on imaging in the ER before catecholamines were measured--the reverse of the usual practice--adrenal "incidentalomas" are common while pheochromocytomas are rare.
8) The biochemical synthesis of the different catecholamines and their metabolites is shown in Figure 1.
2003) that catecholamines hormones is one of the hormones pressures It consists of (adrenaline-norepinephrine dopamine), and it can be inferred from these hormones in urine by measuring the Vanillylmandelic acid (VMA), this is an indication of the levels of catecholamines hormones.
Giant cystic pheochromocytoma containing high concentrations of catecholamines and metanephrines.