Studies on the interaction of microwave radiation with cholinesterase.

The significance of the enzyme cholinesterase in studies on the biological effects of microwaves is discussed. Experiments were performed on the direct effect of microwave radiation on the enzyme activity in aqueous solution, and in rabbit blood. Microwave radiation was found to have an effect only when the temperature increase was great enough to denature the enzyme.

[Effect of low-intensity laser radiation on the brain cholinesterase activity of rats]. / Vliianie nizkointensivnogo lazernogo izlucheniia na aktivnost' kholinésterazy mozga krys.

In studying the activity of cholinesterase in subcellular fractions of rat brain affected by laser radiation of low intensity (9 mW) symbasic changes were noted which were more pronounced in vitro than in vivo.

The effect of phytochrome action on the activity of cytosolic cholinesterase in oat cells.

Cholinesterases in the oat cell were found to be distributed in the cell wall (50%) and cytoplasm (42%). Activity of the cytosolic enzyme was inhibited about 80% by 1 mM Ca2+. The enzyme activity was also inhibited by Mn2+, but no inhibition by Mg2+ was observed. Effects of red light and calcium ion on the enzyme activity were investigated in vivo to confirm the involvement of phytochrome action in the regulation process of this enzyme via Ca2+. It was observed that inhibition by red light only occurs when external Ca2+ existed in the cell medium. Based on a previous report (8) that red light stimulates the influx of Ca2+ into the cytosol of oat cell, inhibition of the enzyme activity by irradiation of red light can be suggested to occur via the influx of Ca2+.

[Enzymatic and morphological study of the liver in acute radiation sickness]. / Enzimno i morfologichno izsledvane na cherniia drob pri ostra lucheva bolest.

The morphologic changes in the liver were investigated along with those in the activity of the specific liver enzymes in the blood plasma of rats in the case of the severe form of acute radiation disease. The rats were treated with 670 Rad at the rate of 90 Rad/min. The studies were carried out on the 1st, 8th , 15th, 22nd, and 30th day following irradiation. It was found that under the conditions of the experiment the activity of the cytoplasmic enzymes sorbitoldehydrogenase , cholinesterase, and leucinaminopeptidase strongly rose on the 1st day after treatment (the activity of sorbitoldehydrogenase increased 11 times). The activity of acid phosphatase and glutamate dehydrogenase also increased strongly, whereupon there was deterioration of the mitochondrial and lysosomal structures. Seen were well expressed processes of fatty and parenchymal dystrophy. The studies on the changes in the activity of these enzymes can be used as an adjunct, resp., an auxiliary test to the haematologic indices in the evaluation of the severity of radiation disease.

Short time observations of morphological changes and cholinesterase distribution in lymphatic organs of the mouse after corticosteroid and X-ray treatment.

The changes in thymus, spleen and lymph nodes of the mouse after a single cortisone application or a single whole body x-irradiation were investigated morphologically and histochemically. During 24 h the alterations following the cortisone application are at all stages examined indistinguishable from those following the x-irradiation. The first signs of lymphocyte destruction can be observed already in the first two hours after treatment. Almost at the same time macrophages accumulate at the sites of cell death in the lymphatic organs studied. The eosinophils display a different behaviour. While they accompany the macrophages in the thymus already at the first stages, they appear in the spleen and lymph nodes with a latency of 6 and 8 h, respectively. The highest amount of necrotic cells is found ten hours after both treatments. At the same time the accumulation of macrophages and eosinophils reaches its maximum. The cholinesterase in the lymphatic organs is largely the true cholinesterase. The enzyme-activity increases in the cortex of the thymus gradually 6 h after treatment, showing the highest deposit of reaction product at 10 h. In spleen and lymph nodes the cholinesterase shows only slight variations. The possible role of the cholinesterase-activity in these non-cholinergic tissues is discussed.

Use of 300-msec microwave irradiation for enzyme inactivation: a study of effects of sodium pentobarbital on acetylcholine concentration in mouse brain regions.

Microwave irradiation of 6 kw at 2450 MHz for 300 msec was sufficient to completely inactivate mouse brain cholinesterase and choline acetyltransferase. After this method of sacrifice, the acetylcholine contents of mouse brain regions, given in nanomoles per gram, were found to be: striatum, 81; medulla-pons, 44; diencephalon-midbrain, 34; hippocampus, 31; cerebral cortex, 26; and cerebellum, 17. Sodium pentobarbital caused a dose-dependent increase in whole brain acetylcholine. A maximal increase of 81% in whole brain was seen at 15 minutes with 80 mg/kg of sodium pentobarbital. The increase in acetylcholine after sodium pentobarbital treatment was not caused by anoxia from respiratory depression or by hypothermia. All brain regions except the cerebellum exhibited an increase in acetylcholine after pentobarbital treatment. Fifteen minutes after treatment, cerebellar acetylcholine was significantly decreased. However, at the time when half of the animals had regained the righting reflex, the unconscious mice showed an increase in cerebellar acetylcholine which was statistically significant as compared to control. The relative accumulation rate of acetylcholine calculated for cerebral cortex and hippocampus was higher than that for striatum although the absolute rate of accumulation of ACh was higher in the striatum. Thus, after sodium pentobarbital treatment, the cerebral cortex and hippocampus exhibit a greater cholinergic response than the striatum.

Microwave fixation of brain tissue as a neurochemical technique- a review.

Microwave devices have been developed for rapidly inactivating brain enzymes by focusing the power output into the heads of small laboratory animals. The rapid inactivation achieved prevents postmortem changes and permits the measurement of neurochemicals such as acetylcholine at concentrations close to those obtained in vivo. The technique promises the assay of neurochemical parameters not possible before.

[The effect of the parenteral administration of alpha-ketoglutarate on the resistance of rats to ionizing radiation and on their cholinergic systems]. / Vplyv parenteral'noho vvedennia al'fa-ketohlutaratu na rezystentnist' shchuriv do ionizuiuchoho oprominennia ta kholinerhichnu systemu ïkh orhanizmu.

We have investigate the effect of sodium ketoglutarate intraperitoneal injection (20 mg/100 g body weight) made 0.5 hour before and 1, 2 and 3 hours after total X-ray treatment (259 mKl/kg) on the survival of rats. Simultaneously we have define changes in cholinesterase-acetylcholine system and content of adrenaline and noradrenaline in liver and pancreas tissues, small intestines mucous and in blood. All the data were taking at 1, 2, 5, 4, 24 and 72 hours after treatment and sodium ketoglutarate injection. We have found that sodium ketoglutarate injection made 0.5 hour before the treatment results in increasing of percentage death rate and injection made 1 and 2 hours after treatment results in increase in survival of rats. The effect of alpha-ketoglutarate injection made 1 hour after treatment in more pronounced. It is accompanied with increase of cholinergic status of organism on the catecholamine deficit background, decrease in the cholinesterase activity and increase of acetylcholine content in tissues of treated organism.