Papers by Sinerik Ayrapetyan
Open Journal of Biophysics
The elucidation of the mechanism on the biological effects of weak chemical and physical factors ... more The elucidation of the mechanism on the biological effects of weak chemical and physical factors on cells and organism is one of the modern problems in life sciences. According to the Receptor Theory of Prof. Bernard Katz the impact of the biological substances on cells is realized through the activation of ligand-gated ion channels in the membrane. However, this theory doesn't provide a satisfactory explanation on the similar biological effects of extremely low concentrations of different chemical substances, which are unable to activate the ionic channels in the membrane and have non-linear dose-dependent effect on cells. Previously we have suggested that the metabolic control of cell hydration serves as a universal quantum-mechanical sensor for different weak physical and chemical signals. For supporting this hypothesis, in this article the comparative study of the effects of low concentrations of both cold (non-radioactive) and [ 3 H]-ouabain (specific inhibitor for Na + /K +-ATPase) on the hydration in different tissues of rats has been performed. The obtained data have shown that cold and [ 3 H]-ouabain have different effects on cell hydration and such a difference depends on the initial metabolic state of tissues. On the basis of our previous and present results it is suggested that such a quantum-mechanical sensitivity of cell hydration is realized through the cyclic-nucleotides-dependent Na + /Ca 2+ exchange, having a crucial role in the metabolic regulation of cell hydration.
International Journal of Basic and Applied Sciences, 2016
Based on our previous finding that metabolically controlled cell hydration is sensitive to the ch... more Based on our previous finding that metabolically controlled cell hydration is sensitive to the changes of physicochemical properties of cell aqua medium, which take place upon the effect of weak physical signals, including microwaves with non-thermal intensity (NT MW), it has been hypothesized that cell aqua medium serves as a primary target for NT MW effect on brain tissue. To elucidate the nature of the metabolic pathway through which the effect of NT MW-induced changes of physicochemical properties of cell aqua medium modulate cell hydration, the effects of intraperitoneal (IP) injection of PS treated by NT MW on brain tissue hydration, 45Ca2+ uptake, [3H]-ouabain binding with cell membrane and intracellular cyclic nucleotides have been studied. The obtained data indicate that PS treated by NT MW through the activation of high affinity ouabain receptors in membrane stimulates cAMP-dependent Na+/Ca2+ exchange in reverse mode (R), which leads to brain tissue hydration in healthy (y...
... Armenuhi Heqimyan1, Anush Deghoyan1, Sinerik Ayrapetyan1* 1. UNESCO Chair-Life Sciences Inter... more ... Armenuhi Heqimyan1, Anush Deghoyan1, Sinerik Ayrapetyan1* 1. UNESCO Chair-Life Sciences International Postgraduate Educational Center, 31 Acharyan St. ... For all statistical tests (with Student's t-test) P value of 0.05 or less taken as (*P < 0.05, **P < 0.01, ***P < 0.001). ...
... groups was statistically significant (***P<0.001). Page 7. Journal of International Dental... more ... groups was statistically significant (***P<0.001). Page 7. Journal of International Dental And Medical Research ISSN 1309-100X Analgesic effect of hypertonic solution http://www. ektodermaldisplazi.com/journal.htm Sinerik Ayrapetyan, Gohar Musheghyan, and Anush ...
The Environmentalist, 2012
ABSTRACT The aim of this work was to investigate the frequency-dependent effects of extremely low... more ABSTRACT The aim of this work was to investigate the frequency-dependent effects of extremely low-frequency electromagnetic field (ELF-EMF) and mechanical vibration at infrasound frequency (MV at IS frequency or MV) on growth and development of Escherichia coli K-12, by using classical microbiological (counting colony forming units), isotopic, spectrophotometric and electronmicroscopic methods. The frequency-dependent effects of MV and ELF-EMF were shown that they could either stimulate or inhibit the growth and the division of microbes depending on the periods following exposure. However, the mechanism through which the MV and ELF-EMF effects affect the bacteria cell is not clear yet. It was suggested that the aqua medium could serve a target through which the biological effect of MV and ELF-EMF on microbes could be realized. To check this hypothesis, the frequency-dependent effects (2, 4, 6, 8, 10 Hz) of both MV and ELF-EMF on the bacterial growth, division and their motility in cases of exposure, the preliminary treated microbes-free medium and microbes containing medium were studied. Both MV and ELF-EMF effect on microbes have frequency and post-exposure period duration-dependent characters. The [3H]-thymidine involving experiments shown that EMF at 4 Hz exposure has pronounced stimulation effect on cell proliferation while 4 Hz MV has inhibition effect. But at 8–10 Hz, the both EMF and MV have inhibitory effects on cell proliferation. It is suggested that 4 and 8 Hz EMF have different biological effects on microbes.
1. The nitric oxide (NO) donor S-nitro-N-acetyl-penicillamine (SNAP) inhibits Helix aspersa heart... more 1. The nitric oxide (NO) donor S-nitro-N-acetyl-penicillamine (SNAP) inhibits Helix aspersa heart activity and relaxes muscles. 2. K-free saline and ouabain both depress SNAP-induced relaxation in most experiments, but in a few preparations they either had no effect or potentiated SNAP-induced relaxation. 3. Na-K pump reactivation following preincubation in K-free saline leads to the pronounced transient relaxation of heart muscle, the magnitude of which depends on the duration of preincubation. 4. 0.1 mM SNAP inhibited the ouabain sensitive part of 86Rb uptake, which reflects Na-K pump activity. This inhibition is potentiated by phospholipase C. 5. SNAP increased cGMP levels in the heart. 6. These results indicate that SNAP-induced relaxation depends on Na and Ca gradients across the membrane, which suggests that Na:Ca exchange is involved in the mechanisms of SNAP-induced relaxation. It is postulated that SNAP elicits its inhibitory effect on the heart through a cGMP-dependent Na:Ca exchange.
... peripheral nerves. Biochem. Biophys. Acta 23: 394-401. Stepanyan R., Ayrapetyan G., Arakelyan... more ... peripheral nerves. Biochem. Biophys. Acta 23: 394-401. Stepanyan R., Ayrapetyan G., Arakelyan A., Ayrapetyan S. Effect of Mechanical Oscillations on Electrical Conductivity of Water. Biophysics, v.44, pp.197-202, 1999. List of ...
Journal of Bioequivalence & Bioavailability, 2013
Journal of Bioequivalence & Bioavailability, 2013
Effect of intraperitoneally (i.p.) injected sub-anesthetic (8×10-5-8×10-2 mg/g) and anesthetic (0... more Effect of intraperitoneally (i.p.) injected sub-anesthetic (8×10-5-8×10-2 mg/g) and anesthetic (0.1 mg/g) doses of ketamine on rats' pain sensitivity and tissue hydration were studied. Determination of water content of tissue was performed by Adrian's traditional "tissue drying" experimental procedure. The number of functionally active receptors were determined by counting the number of [ 3 H]-ouabain molecules in tissues. Latent period of pain sensitivity was defined by means of hot plate test. Ketamine in sub-anesthetic doses had depressing effect on rats' latent period of pain sensitivity which was accompanied by tissues' dehydration. [ 3 H]-ouabain influence on brain tissues hydration was characterized by dose dependent three phases and this fact was accompanied by corresponding changes of ouabain receptors number in cell membrane. Ketamine in anesthetic dose had reversing effect on ouabain-induced cell hydration and it was different for each brain tissue. It was suggested that ketamine-induced cell dehydration leading to decrease of number of functional active proteins in membrane serves as a powerful mechanism through which an analgesic and anesthetic effects of ketamine on organisms were realized.
Journal of Neurochemistry
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Journal of Membrane Biology
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Journal of Membrane Biology
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Microbiology
... Impact of magnetic fields on growth dynamics and acid formation in lactic acid bacteria. Aute... more ... Impact of magnetic fields on growth dynamics and acid formation in lactic acid bacteria. Auteur(s) / Author(s). ALAVERDYAN ZH. R. (1) ; AKOPYAN LG (1) ; CHARYAN LM ; AIRAPETYAN SN ; Affiliation(s) du ou des auteurs / Author(s) Affiliation(s). ...
Eksperimental'naia i klinicheskaia farmakologiia
The authors studied the effect of the ketamine anesthetic on hydration of tumoral and normal glan... more The authors studied the effect of the ketamine anesthetic on hydration of tumoral and normal glandular cells and on the binding of labelled ouabain with the tissues in order to reveal changes in the number of active Na-K-ATPase molecules on the cell membrane. Hydration of tumoral and normal cells diminished in one-hour incubation in a solution of narcotic and subnarcotic doses of ketamine based on Tyrode&#39;s solution. The binding of ouabain by 3H also sharply reduced in a concentration of 10(-8) M in 30 min incubation, after incubation of pieces of tissues in ketamine, which was also evidence of reduction of the cell volume. This proves that the content of water in the tumoral cells increases and that ketamine in subnarcotic doses exerts a selective effect on tumoral cells.
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Papers by Sinerik Ayrapetyan