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Sulfites are previously demonstrated to increase the photodegradation of epinephrine. The aim of this study was to clarify the factors responsible for this effect. Adrenochrome sulfonate seems to be the important substance. Photoproduction of singlet oxygen is indicated to be the mechanism by which adrenochrome sulfonate acts. Protection of epinephrine solutions from irradiation <418 nm prevented the photodegradation. A reaction pathway for thephotochemical decomposition of epinephrine in the presence of bisulfite is suggested.

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Preponderance in depression of the melancholy affect was characterized by a drop in the level of norepinephrine (NE) and rise in epinephrine (E). Exposure to light was associated with fall in E, with no change recordable in NE. In anxious depression, following light therapy, high levels of excretion of both catecholamines tended to return to normal. Ligh was found to cause opposite changes in the quantitative measures depending upon the initial value for the E:NE ratio (above or below control).

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The action of bright light (2600-2800 lux) on the catecholamine (CA) excretion was analyzed in patients with anxious (11) and melancholic (12) depressions resultant from manic-depressive psychosis and schizophrenia. The melancholic depressed patients were characterized by decreased noradrenaline (NA) and increased adrenaline (A) levels; in anxious depression NA and A were increased. The light therapy resulted in decrease of A level but NA level remained invariable in melancholic depression. Meanwhile the tendency to normalization of excretion of both CA was observed in anxious patients after light therapy. The contrary alterations in A/NA ratio as well as its considerable individual fluctuations were observed after light therapy. The A/NA ratio after light therapy depended mainly upon the initial A/NA ratio (the higher or lower ratio compared to control value).

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The influence of natural radioprotectors (MIGI-K and carnosin) on the dynamics of catecholamines level in adrenal glands of irradiated rats was shown. Carnosin and MIGI-K take part in developing of organism radioresistance. Carnosin action is due to mobilisation of endogenous radioprotective agents (catecholamines) while MIGI-K influences on the restoring of their level.

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Lidocaine with epinephrine is currently the most common local anesthetic agent used for facial soft tissue surgery. This combination is generally safe and effective in providing complete anesthesia and adequate hemostasis. Because epinephrine is unstable at physiologic pH, the commercial preparation is formulated with a low pH (3.5-5.5). Unfortunately, this acidic pH causes significant pain during infiltration. To reduce pain, clinicians sometimes buffer acidic local anesthetic agents with sodium bicarbonate. However, little is known about the stability of epinephrine when the pH of epinephrine is clinically altered. Using high pressure liquid chromatography (HPLC), epinephrine levels were measured after the addition of sodium bicarbonate. Our results indicate a significant amount of epinephrine degradation occurs in some of these specimens. Recommendations regarding the use of buffered local anesthetic agents are made.

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Repeated exposure of guinea pigs to microwave radiation (1 mW/cm2) caused in some animals inhibition of anaphylactic response accompanied by increasing the content of histamine, epinephrine and norepinephrine in the blood. This increase was more pronounced in irradiated guinea pigs died from anaphylactic shock than in nonirradiated animals. The long-term stay in the perturbed and weak geometric field reduced the effect induced by microwave radiation.

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The anaphylactic shock and alterations in the epinephrine and norepinephrine content of the blood were inhibited in guinea pigs which were repeatedly kept at high temperature (50 degrees C). Preirradiation with a dose of 1 Gy prevented this effect.

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Advanced life support medications stored in emergency department stretcher areas, diagnostic radiology rooms, and radiotherapy suites are exposed to ionizing radiation. We hypothesized that radiation may decrease the potency and thus the shelf life of medications stored in these areas. Atropine, dopamine, epinephrine, and isoproterenol were exposed to a wide range of ionizing radiation. The potency of the four drugs was unaffected by levels of radiation found in ED stretcher areas and high-volume diagnostic radiograph rooms (eg, chest radiograph, computed tomography, fluoroscopy). The potency of atropine may be reduced by gamma radiation in high-use radiotherapy suites. However, dopamine, epinephrine, and isoproterenol were unaffected by high doses of gamma radiation. Atropine, dopamine, epinephrine, and isoproterenol may be safely kept in ED stretcher areas and diagnostic radiology rooms without loss of potency over the shelf life of the drugs.

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The catecholamine content was quantitated and acetylcholinesterase activity determined in rat brain locally exposed to laser radiation. It was shown that the adrenaline/noradrenaline ratio changed in the tissues under study and the cholinergic system was involved in the abscopal effect of laser radiation.

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The changes were studied in the levels of catecholamines and L-DOPA in the control system of reproduction cycle (hypothalamus, hypophysis) and in adrenal glands of sheep after all-body irradiation with 60Co at the total dose of 6.7 Gy for seven days. The power input per hour of irradiation source was 0.039 Gy. The catecholamines (noradrenaline, dopamine and adrenaline) and L-DOPA were determined, after having been isolated from the tissues, by the method of spectral fluorimetry. After all-body exposition to gamma-radiation noradrenaline dropped in hypothalamus in comparison with the control group of sheep, most significantly in the rostral (by 74.2%) and caudal part (by 40%). A similar drop like in the case of noradrenaline was also observed in dopamine, the concentrations of which decreased in rostral hypothalamus by 72%, in medial hypothalamus by 94% and in caudal hypothalamus by 60%. Adrenaline shows a drop in hypothalamus, most significant in caudal region (by 62%). In relation with that the level of a precursor for the synthesis of catecholamines and L-DOPA has been changed which achieved, in the studied regions of hypothalamus in sheep, significantly lower levels than were determined in the control group of sheep. As regards the hypophysis, after irradiation no significant changes in the levels of noradrenaline and adrenaline were recorded, however, dopamine and L-DOPA dropped significantly (P less than 0.01). The exposition to gamma-radiation also causes a decrease in the concentrations of catecholamines and L-DOPA in the adrenal glands of sheep, most significant in noradrenaline (by 61%).(ABSTRACT TRUNCATED AT 250 WORDS)

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Experiments on adult rats have shown that a single rectal x-ray irradiation is accompanied by a decrease in the content of adrenaline, noradrenaline and potassium and by a increase in sodium and calcium concentration in vascular tissue. The degree of these shifts depends on the time elapsed after exposure to x-rays. X-Ray injury produces specific changes in the biochemical response of the vascular wall to different doses of acetylcholine and histamine during varying times of x-ray-induced pathology. Pretreatment (before irradiation) with radioprotectors (cistamine) lowers the damaging effect of radiation and promotes the normalization of the vascular tissue response to the administration of mediator agents.

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Carpules of commercially available local anaesthetic solutions containing adrenaline have been exposed to varying conditions of heat, ultra-violet and infra-red light over a period of two months. The adrenaline content in the solutions was assessed by fluorometric assay both at the commencement of study and at regular intervals over the period of exposure. Infra-red light appeared to have little or no effect on the concentration of adrenaline, while ultra-violet light, either alone or in combination with infra-red light, caused the adrenaline levels to diminish rapidly. The results suggest that the ultra-violet component of light is probably responsible for the breakdown of catecholamines in local anaesthetic solutions when these solution are stored in areas exposed to sunlight.

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Adrenaline (epinephrine), adrenochrome and C4-substituted catechol model compounds were pulse-irradiated in aqueous neutral and alkaline solutions. Transient spectra are reported after oxidizing adrenaline and reducing adrenochrome. All species appearing during 20 msec interval after the pulse have been identified: the OH adduct with an absorption maximum at 300-310 nm, the semiquinone (at 245 nm), and adrenaline quinone (at 340 nm). The reaction of superoxide anions (O2-) with adrenaline was less efficient, compared with OH radicals. A novel oxidation product, derived from the semiquinone and O2-, has been identified as the 4-hydroxy-3,6-dioxo derivate. The pulse-radiolytic reduction of adrenochrome by hydrated electrons (eaq-) yielded the semiquinone of adrenochrome (absorbing at 470 nm), which subsequently decays by a second-order process. The dismutation products leuco-adrenochrome (absorbing at 300 nm, pH 9-8) and the adrenochrome tautomer (absorbing at 375 nm) are unstable, forming 5,6-dihydro-N-methyl indole and regenerating adrenochrome.

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