We studied combined effect of the β-adrenoreceptor agonist isoproterenol and the Y receptor agonist [Leu31, Pro34]neuropeptide Y on the frequency of spontaneous activity and myocardial contractility in 21- and 100-day-old rats. Isoproterenol increased the frequency of spontaneous activity and reduced the main parameters of isometric contraction of the atrial myocardium. When [Leu31, Pro34]neuropeptide Y was added, the frequency of spontaneous activity and the negative inotropic and the positive chronotropic effects of isoproterenol were reduced in 100-day-old rats. In 21-day-olds rats, a tendency to a decrease in the effect of isoproterenol was observed.
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http://dx.doi.org/10.1007/s10517-023-05694-5 | DOI Listing |
J Clin Monit Comput
January 2025
IRCCS Humanitas Research Hospital, via Manzoni 56, Rozzano - Milan, 20089, Italy.
Fluids are given with the purpose of increasing cardiac output (CO), but approximately only 50% of critically ill patients are fluid responders. Since the effect of a fluid bolus is time-sensitive, it diminuish within few hours, following the initial fluid resuscitation. Several functional hemodynamic tests (FHTs), consisting of maneuvers affecting heart-lung interactions, have been conceived to discriminate fluid responders from non-responders.
View Article and Find Full Text PDFIsotopes Environ Health Stud
January 2025
Research Institute of Biology, Yerevan State University, Yerevan, Republic of Armenia.
Plant test systems are a sensitive way to detect the genetic effects of various contaminants in environmental compartments: water, soil and sediments. Biotesting of the genotoxicity of soil samples with various activity concentrations of naturally occurring (Ra, Th, K) and artificial (Cs) radionuclides in soil, from the territory of the Aragats Massif (Armenia) was carried out with the application of the micronucleus (Trad-MСN) and stamen hair mutation (Trad-SHM) bioassays of (clone 02) model test-object in the soil - plant system. Undisturbed soil sampling was performed in the southern slopes of the Aragats Massif, from different altitudes (from 1000 to 3200 m above sea level).
View Article and Find Full Text PDFUnlabelled: Exposure to loud and/or prolonged noise damages cochlear hair cells and triggers downstream changes in synaptic and electrical activity in multiple brain regions, resulting in hearing loss and altered speech comprehension. It remains unclear however whether or not noise exposure also compromises the cochlear efferent system, a feedback pathway in the brain that fine-tunes hearing sensitivity in the cochlea. We examined the effects of noise-induced hearing loss on the spontaneous action potential (AP) firing pattern in mouse lateral olivocochlear (LOC) neurons.
View Article and Find Full Text PDFIn bacteria, spontaneous mRNAs degradation and ribotoxin-induced RNA damage are two main biological events that lead to the stall of protein translation. The ubiquitous trans-translation system as well as several alternative rescue factors (Arfs) are responsible for rescuing the stalled ribosomes caused by truncated mRNAs that lack the stop codons. To date, protein release factor homolog (PrfH) is the only factor known to rescue the stalled ribosome damaged by ribotoxins.
View Article and Find Full Text PDFUnlabelled: The locus coeruleus (LC) is the primary source of noradrenaline (NA) in brain and its activity is essential for learning, memory, stress, arousal, and mood. LC-NA neuron activity varies over the sleep-wake cycle, with higher activity during wakefulness, correlating with increased CSF NA levels. Whether spontaneous and burst firing of LC-NA neurons during active and inactive periods is controlled by mechanisms independent of wakefulness and natural sleep, is currently unknown.
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