Adrenoreception characteristics of the neurons of the superior cervical and caudal mesenteric sympathetic ganglia of the cat]

Experiments were conducted on the supeior cervical and the caudal mesenteric sympathetic ganglia of a cat; it was shown that dophamine (DA), similarly to noradrenaline (NA) and adrenaline (A), depressed the cholinergic conduction. The activity of DA in the superior sympathetic ganglion was less than that of the NA and A 2- and 3-fold, respectively, and in the caudal mesenteric ganglia DA was 50 times more active than NA by the capacity to depress the cholinergic conduction. The effects of DA and NA in the superior cervical ganglia were eliminated by dyhydroergotamine, phentholamine and haloperidol, but not by tropaphen and chlorpormazine. In the caudal mesenteric ganglia the inhibitory effect of NA was decreased by phentholamine, dihydroergotamine and chlorpromazine, but not by haloperidol. On the contrary, haloperidol and chlorpromzine decreased the depressive effect of DA on the cholinergic conduction in the caudal mesenteric ganglion, whereas phentholamine, dihydroergotamine and deseryl proved to be ineffective. It is supposed that the manifestation of the dopaminergic mechanism of inhibition of cholinergic conduction in the caudal mesenteric sympathetic ganglion could underlie the dilatation of the mesenterial and renal vessels and its hypotensive action caused by DA.     

The comparative effect of serotonin agonists on the presynaptic and somatodendritic autoreceptors of serotoninergic neurons

Experimenting on the slices of cortex and dorsal raphe nucleus of midbrain of rats which were incubated with 3H-hydroxytrypta-mine (3H-HT) studies showed the influence of series of serotonin agonists on the spontaneous and electrically stimulated release of 3H-HT from the slices. It was established that the serotonin in concentration of 10(-5) mol/l similarly inhibits the release of 3H-HT from the electrically stimulated slices of the brain cortex (78.6%) and on slices of the dorsal raphe nucleus of the midbrain (81.6%) had no effect on the spontaneous release of serotonin. The serotonin agonists in order of increasing ability to inhibit the electrically stimulated release of 3H-HT from the cortex slices is as follows: ipsapirone (0%), 8-OH-DPAT (23%), kampirone (26.5%), 1.2-PP (28.6%), kaplapirone (35.7%), buspirone (48%) and TFMPP (67%). On the ability to influence the release of 3H-HT from the electrically stimulated slices of the dorsal raphe nucleus of the midbrain of the rats serotonin agonists were in the following order: TEMPP (12.3%), kampirone (40%), 1.2-PP (42.9%), ipsapirone (52%), 8-OH-DPAT (54.1%), kampirone (57.2%) and buspirone (65.3%). It is suggested that the effect of both ipsapirone, kampirone and 8-OH-DPAT is greatly localized on the somato-dendritic synapses P1A-HT receptors, TEMPP is more on the terminal axons of HT-ergic neurones while kampirone, buspirone and active metabolite 1.2-PP act on the presynaptic and somatodendritic autoreceptors of serotonin.     

Ion-dependency of the GABA-potentiating effects of benzodiazepine tranquilizers and harmane

Experiments on an isolated spinal cord of 8-15-day-old rats have shown that one of the possible mechanisms of the GABA-potentiating action of the benzodiazepine tranquilizer, chlorodiazepoxide, may be a decrease in the intraneuronal concentration of Ca2+. This is evidenced by the enhancement of the GABA-potentiating action of chlorodiazepoxide under Ca2+ deficiency in the medium and in the presence of the blockers of the voltage-dependent Ca2+ ionic channels--Mn2+ and Co2+, and by the reduction of the effect in question under Ca2+ excess in the medium and in the presence of the K+ channels blockers--tetraethylammonium and 4-aminopyridine. The GABA-potentiating action of harmane is likely to be related to the blockade of the voltage-dependent K+ channels and elevation of the intracellular concentration of Ca2+.     

Effects of serotonin-IA receptors on amino acid and dopaminergic responses of neurons]

By using intracellular technique the authors studied the responses of frog spinal motoneurones and rat dorsal root ganglion evoked by GABA, L-aspartate and dopamine in the presence of 5-hydroxytryptamine and its 1A-agonists or without them. It is shown that buspirone, campirone and serotonin increase the GABA effects but inhibit the effects of aspartate via the GABA- and NMDA-receptors modulation.     

Photovoltaic effect in pigment films in contact with an electrolytes. V. Theory of the Becquerel photovoltaic effect in porous films of phthalocyanine]

In accordance with literature and our experimental data a theoretical analysis of the model system metal-porous film of the pigment-electrolyte was carried out at stationary illumination in the regimes of photocurrent and photopotential. The main properties and positions of the model are supported experimentally. Specific behaviour of the photovoltaic system considered resides in the discovered dependence of the transfer mechanism on the value of catode potential of the electrode.     

Prolonged administration of antidepressants induces changes in the pulsed release but not in the reverse uptake of biogenic amines

The experiments on rats have shown that antidepressant concentrations that cause 50% inhibition of 14C-NA and 3H-HT uptake by brain slices remain unchanged following prolonged administration of antidepressants (imipramine, pirazidole, harmane and its derivatives--C-153, C-307, C-394, C-395), as compared to the control. Electrical stimulation of brain slices upon long-term treatment of rats with antidepressants and preincubation with 14C-NA and 3H-HT enhanced presynaptic release of radioactive mark at concentrations of antidepressants (EC2) 3-14 times lower than those in the control animals. Long-term antidepressant administration reduces the inhibitory influence of clonidine and HT on presynaptic release of 14C-NA and 3H-HT by brain slices. It is suggested that long-term administration of antidepressants decreases the sensitivity of terminal axons of NA- and HT-ergic neurons to autoinhibitory effect of neurotransmitter release.     

Increase in Sensitivity of HEK293FT Cells to Influenza Infection by CRISPR-Cas9-Mediated Knockout of IRF7 Transcription Factor

Russian Journal of Bioorganic Chemistry - Interferon-regulated factors play a central role in the activation of the innate immune response. The interferon-regulatory factor 7 (IRF7) is one of the...     

Ebola hemorrhagic fever: Properties of the pathogen and development of vaccines and chemotherapeutic agents

Molecular Biology - Ebola hemorrhagic fever (EHF) epidemic currently ongoing in West Africa is not the first among numerous epidemics in the continent. Yet it seems to be the worst EHF epidemic...     

Optical properties of mixtures of beta-carotene and chlorophyll a adsorbed on bovine serum albumin

The fluorescence of the natural photosynthetic pigments beta-carotene (beta-K) and chlorophyll a (Chl) and their mixtures with bovine serum albumin (BSA) in different molar ratios has been studied. An increase in the fluorescence intensity in a pigment mixture-BSA complex was found. The highest possible (four- to sixfold) increase in the fluorescence intensity compared with fluorescence intensity of one-pigment BSA complexes BSA (beta-K) and BSA (Chl) was achieved at the ratio 11-27% beta-K/89-73% Chl in the BSA complex. A considerable overlap of fluorescence spectra of BSA (Chl) complex (lambda(max) at 690 nm) and BSA (beta-K) complex (lambda(max) at 684 nm) was observed.