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Biomedical subjects

N R Elaev

Publications and source records attributed to N R Elaev.

At least 19 recordsLinked to original sources
PubMed1992

[Anomalous excretion of glycosaminoglycans in patients with syringomyelia].

Glycosaminoglycan (GAG) urine concentrations in syringomyelia patients were much higher than in healthy subjects from January to September. Maximum values of GAG excretion (twice as much as control) in affected patients were observed in spring and summer (from March to July). The results suggest that syringomyelia is accompanied by disorders in GAG connective tissue accumulation.

Adult↗
PubMed1986

[Plasma enzymes inactivating alkaloids].

It was shown that rat blood plasma contains two enzymes that inactivate alkaloids by transforming them into N-oxides. Both enzymes are hemoproteins: one of them consists of three different polypeptides with Mr of 63, 35 and 12 kD, while the other one is a single polypeptide with Mr of 73 kD. Both enzymes exhibit cooperative properties.

Alkaloids↗
PubMed1985

[Blood protein-inactivating atropine].

A xenobiotics-inactivating hemoprotein related to the class of pharmacologically active compounds (cholinolytics) was detected in rat blood. Ammonium sulphate fractionation, DEAE cellulose chromatography and gel filtration on Sephadex G-75 resulted in 750-fold purification of the protein; its Mr = 73 000-80 000. Multiple injections of the protein to experimental animals led to a 2-3-fold increase of the protein content in the blood.

Animals↗
PubMed1983

[Endogenous activators and inhibitors of Na, K-ATPase induced by acetylcholine].

Preincubation of rat brain homogenates with acetylcholine (ACh) in concentrations of 10(-3)-10(-5) M for 60 minutes produces an essential increment (15-30%) in activity of microsomal Na, K-ATPase. Analogous effect was exerted by the acetylcholinesterase inhibitor eserine (10(-5)-10(-6) M). Acetylcholine has no effect in the presence of actinomycin D. Dialysis of microsomes isolated from the homogenate incubated with ACh leads to a decrease in the enzyme activity and release to the dialysate of low-molecular factor activating Na, K-ATPase of intact microsomes. The latter fact evidences the ACh-induced synthesis of activating factor and inhibition of Na, K-ATPase synthesis. After the animals are administered eserine (0.2-0.4 mg/kg), isolated microsomes show a reduced level of Na, K-ATPase (by 10-15%). Dialysis of microsomes leads to an appreciable elevation (by approximately 40%) of the enzyme activity and release into the dialysate of the inhibitory factor. The differences in the effects of eserine in vivo and in vitro suggest that during the impairment of brain integrity certain effects are excluded from the processes of the control over Na, K-ATPase activity. One of these may involve the impairment of intercellular interactions, for example, the disappearance of the effect on cholinoceptive cells of internuncial neurons that release inhibitory neurotransmitters (catecholamines).

Acetylcholine↗
PubMed1982

[Regulation of acetylcholinesterase level in microsomes of neurons by acetylcholine and cyclic nucleotides].

In a cell-free system containing isolated nuclei and microsomal-cytoplasmic brain fraction there takes place a spontaneous puromycin-sensitive increase in acetylcholinesterase (AChE) activity of microsomes. As a result of preincubating the system with acetylcholine (ACh) (10(-6)-10(-3) M), AChE activity of microsomes was found to be increased, reaching the maximal value at an ACh concentration of 10(-5) M (25% during 60 min incubation). The effect of ACh was not detectable in the presence of actinomycin D and puromycin. Upon removal of the nuclei from the system, preincubation with ACh produces a lowering of AChE activity in microsomes. cAMP and cGMP reduce AChE activity of microsomes in a complete system. The results obtained enable one to consider acetylcholine regulation of microsomal AChE level in nerve cells as a multi-component system. The main component in the system is a direct action of ACh on the synthesis of AChE gene product or on its processing, while the other components (cyclic nucleotides and effect of ACh itself on translation) are elements of correction.

Acetylcholine↗
PubMed1980

[Activation of Na, K-ATPase from nerve cell microsomes by acetylcholine in a model system].

Microsomal Na, K-ATPase is activated by acetylcholine (5 x 10(-6)--10(-5) M) in a cell-free system including neuronal nuclei and the microsomal--cytoplasmic fraction. No enzyme activation by acetylcholine occurs in the presence of puromycin, actinomycin D and ribonuclease or upon removal of the nuclear or microsomal--cytoplasmic fraction from the system. After preincubation with acetylcholine the membranes reveal a better capacity for phosphorylation by [gamma-32P]ATP and dephosphorylation in the presence of ADP and Na+. The ATP binding by the membranes preincubated in a system with acetylcholine is also increased thereby. It was assumed that acetylcholine induces the synthesis of Na, K-ATPase or its protein activator.

Acetylcholine↗
PubMed1978

[Correlation of Na,K-ATPase activity and protein synthesis in nerve cell membranes exposed to acetylcholine].

Acetylcholine (10(-6)--10(-3) M) added to the rat brain homogenate increased that activity of microsomal Na, K-ATPase and (14C)-amino acid incorporation in microsomal proteins. Actinomicin D (5.10(-5) M) eliminated the effect of acetylcholine. It is concluded that acetylcholine induced the synthesis of either Na, K-ATPase itself or some other proteins involved in the enzyme activity regulation.

Acetylcholine↗
PubMed1978

[RNA synthesis in the isolated nuclei of nerve cells treated with acetylcholine].

Acetylcholine modified the incorporation of radioactive precursors 3H-uridine-5-triphosphate, 14C-uridine and 14C-cytidine in RNA of nuclei isolated from the rat brain. This modification has two tendencies: either the activation or the suppretion. The character of the nuclear reaction depends upon the season and animal population. In the presence of actinomycin D (5.10(-5) M), acetylcholine does not influence the precursor incorporation into the nuclear RNA. In the system that involves nuclei+soluble cytoplasmic fraction acetylcholine exerts an effect that is opposite to that when the nuclei are alone. These results suggest that acetylcholine action is mediated by a cytoplasmic factor. Actinomycin D in the presence of cytoplasmic fraction did not influence effects of acetylcholine.

Acetylcholine↗