scholarly journals ECG of rat under action of new metal-complex antixypoxant πq1983 in acute hypoxia

2013 ◽  
Vol 11 (2) ◽  
pp. 45-51
Author(s):  
Denis Vladimirovich Sosin ◽  
Vitaliy Andreyevich Pravdivtsev ◽  
Marina Anatolyevna Yevseyeva ◽  
Andrey Viktorovich Yevseyev ◽  
Petr Dmitriyevich Shabanov
Keyword(s):  
Metal Complex ◽  
Incubation Period ◽  
Inhibitory Action ◽  
Acute Hypoxia ◽  
Rat Myocardium ◽  
Resistance Level ◽  
Before And After ◽  
Electrical Activities ◽  
Complex Substance ◽  
Ecg Data

Fine changes of electrical activities in rat myocardium were studied after oral introduction of new selenium-containing metal-complex substance πQ1983 in dose 100 mg/kg before and after an acute hypercapnichypoxia (AH + Hc) development. A substance for comparison — metabolic antihypoxant amthizole was used by same way and dose. The substances were introduced 90 min before (incubation period) placing of animals into hypoxic chambers with 1.0 L free volume. ECG was recorded continually during both an incubation period and a hypoxic experiment. It has been established that the inhibitory action of the substance πQ1983 on electrical activity of rat myocardium manifests itself like a significant bradycardia. According with ECG data, rats protected with substance πQ1983 show the resistance level to the AH + Hc higher than ones that intake the antihypoxant amthizole. It was proved by peculiarities of early myocardial hypercapnic reactions, parameters of lifespan, and length of so called relative wellbeing period.

Acute hypoxia influence on cardio-respiratory system and new possibilities of pharmacological prophylactics of hypoxia in experiment

2016 ◽  
Vol 14 (1) ◽  
pp. 37-45
Author(s):  
Andrei V Evseev ◽  
Vitaliy A Pravdivtsev ◽  
Denis V Sosin ◽  
Marina A Yevseyeva
Keyword(s):  
Metal Complex ◽  
Electrical Activity ◽  
Respiratory System ◽  
High Resistance ◽  
Acute Hypoxia ◽  
Cardiorespiratory System ◽  
Resistance Level ◽  
Hypoxia With Hypercapnia ◽  
Hypercapnic Hypoxia ◽  
Complex Substance

Cardiorespiratory system activities have been studied on rats in experiment after oral introduction of the new selenium-containing metal-complex substance πQ1983 in dose 100 mg/kg before and under action of acute hypercapnic hypoxia (AH + Hc). The substance was introduced 90 min. before (incubation period) placement of animals into hypoxic chambers with 1.0 L free volume. During each experiment as well as during AH+Hc an electrical activity of myocardium (ECG) and respiration curves called pneumobarogramm (PBG) were recorded simultaneously. It has been established that the substance πQ1983 made cardiodepressive effect and decreases parameters of lungs ventilation in animals. According to ECG and PBG dynamics, rats protected by the substance demonstrated a high resistance level to the aroused acute hypoxia with hypercapnia, that expressed by weakening of early reactions from cardiorespiratory system under hypercapnia action, and by twice longer life span of animals in hypoxic experiment.

scholarly journals Dynamics of energy metabolism under action of new selenium containing metal-complex substance

2014 ◽  
Vol 12 (1) ◽  
pp. 19-25
Author(s):  
Denis Vladimirovich Sosin ◽  
Andrey Viktorovich Yevseyev ◽  
Edgar Andreyevich Parfenov ◽  
Petr Dmitriyevich Shabanov
Keyword(s):  
Oxygen Consumption ◽  
Energy Metabolism ◽  
Oral Administration ◽  
Metal Complex ◽  
Consumption Rate ◽  
Inhibitory Effects ◽  
Resistance Level ◽  
Energy Processes ◽  
Standard Energy ◽  
Complex Substance

The value of standard energy metabolism had measured on rats after intragastral (oral) administration of the new selenium containing metal-complex substance πQ1983 in dose 100 mg/kg. The well-known antihypoxant amthizol was used as a substance of comparison in a same dose. The substance πQ1983 administered 90 min before study was shown to decrease the activity of energy processes in organism from 194.4 ± 0.7 kcal/day/kg to 74.5 ± 0.5 kcal/day/kg but effect of amthizol was not reliable. It was revealed also that both substances (πQ1983 significantly, amthizol slightly) decreased the oxygen consumption rate during rising acute exogenous hypoxia that could form high resistance level to oxygen insufficiency in rats. Probably, the decrease of oxygen consumption is due to the inhibitory effects of the substances studied, especially substance πQ1983, on active energetic processes in the organism.

scholarly journals Characteristics of external respiration of rats in acute hypercapnic hypoxia and its correction by new metal-complex antihypoxant

2014 ◽  
Vol 12 (2) ◽  
pp. 36-42
Author(s):  
Denis Vladimirovich Sosin ◽  
Andrey Viktorovich Yevseyev ◽  
Vitaliy Andreyevich Pravdivtsev ◽  
Petr Dmitriyevich Shabanov
Keyword(s):  
Metal Complex ◽  
Acute Hypoxia ◽  
Antihypoxic Activity ◽  
External Respiration ◽  
Low Oxygen ◽  
Resistance Level ◽  
Hypoxia With Hypercapnia ◽  
Hypercapnic Hypoxia ◽  
Low Oxygen Concentration ◽  
Respiration Parameters

Changes of external respiration parameters have been studied in experimental rats after oral introduction of new selenium-containing metal-complex substance πQ1983 in dose 100 mg/kg before and under action of acute hypercapnic hypoxia (AH+Hc). A substance for comparison was metabolic antihypoxant amthizole administered in similar way and dosage. The substances were introduced 90 min before (incubation period) placement of animals into hypoxic chambers with 1.0 L free volume. During each experiment as well as during AH+Hc a respiration curve called pneumobarogramm (PBG) was recorded continually. It has been established that the substance πQ1983 decreases parameters of lungs ventilation in the rats. According to PBG dynamics, rats protected by the substance demonstrated a high resistance level to the aroused acute hypoxia with hypercapnia, that expressed by weakening of early reactions from respiratory system under hypercapnia action, twice longer life span of animals in hypoxic experiment, and by rising of possibility to withstand low oxygen concentration. It has been proved that the substance πQ1983 significantly surpass a substance for comparison amthizole in both antihypoxic activity and influence on external respiration parameters.

scholarly journals Chronic intermittent hypoxia alters ventilatory and metabolic responses to acute hypoxia in rats

2016 ◽  
Vol 120 (10) ◽  
pp. 1186-1195 ◽  
Author(s):  
Barbara J. Morgan ◽  
Russell Adrian ◽  
Zun-yi Wang ◽  
Melissa L. Bates ◽  
John M. Dopp
Keyword(s):  
Intermittent Hypoxia ◽  
Acute Hypoxia ◽  
Sprague Dawley ◽  
Glomus Cell ◽  
Stimulus Response ◽  
Sprague Dawley Rats ◽  
Ventilatory Equivalent ◽  
Before And After ◽  
Conscious Animals ◽  
Carotid Body Glomus Cells

We determined the effects of chronic exposure to intermittent hypoxia (CIH) on chemoreflex control of ventilation in conscious animals. Adult male Sprague-Dawley rats were exposed to CIH [nadir oxygen saturation (SpO2), 75%; 15 events/h; 10 h/day] or normoxia (NORM) for 21 days. We assessed the following responses to acute, graded hypoxia before and after exposures: ventilation (V̇e, via barometric plethysmography), V̇o2 and V̇co2 (analysis of expired air), heart rate (HR), and SpO2 (pulse oximetry via neck collar). We quantified hypoxia-induced chemoreceptor sensitivity by calculating the stimulus-response relationship between SpO2 and the ventilatory equivalent for V̇co2 (linear regression). An additional aim was to determine whether CIH causes proliferation of carotid body glomus cells (using bromodeoxyuridine). CIH exposure increased the slope of the V̇e/V̇co2/SpO2 relationship and caused hyperventilation in normoxia. Bromodeoxyuridine staining was comparable in CIH and NORM. Thus our CIH paradigm augmented hypoxic chemosensitivity without causing glomus cell proliferation.

Effect of acute hypoxia on respiration and brain stem blood flow in the piglet

1991 ◽  
Vol 70 (1) ◽  
pp. 251-259 ◽  
Author(s):  
R. A. Darnall ◽  
G. Green ◽  
L. Pinto ◽  
N. Hart
Keyword(s):  
Blood Flow ◽  
Brain Stem ◽  
Minute Ventilation ◽  
Acute Hypoxia ◽  
Extracellular Fluid ◽  
Respiratory Drive ◽  
Peripheral Chemoreceptor ◽  
Before And After ◽  
Spontaneously Breathing ◽  
Local Brain

Changes in local brain stem perfusion that alter extracellular fluid Pco2 and/or [H+] near central chemoreceptors may contribute to the decrease in respiration observed during hypoxia after peripheral chemoreceptor denervation and to the delayed decrease observed during hypoxia in the newborn. In this study, we measured the changes in respiration and brain stem blood flow (BBF) during 2–4 min of hypoxic hypoxia in both intact and denervated piglets and calculated the changes in brain stem Pco2 and [H+] that would be expected to occur as a result of the changes in BBF. All animals were anesthetized, spontaneously breathing, and between 2 and 7 days of age. Respiratory and other variables were measured before and during hypoxia in all animals, and BBF (microspheres) was measured in a subgroup of intact and denervated animals at 0, 30, and 260 s and at 0 and 80 s, respectively. During hypoxia, minute ventilation increased and then decreased (biphasic response) in the intact animals but decreased only in the denervated animals. BBF increased in a near linear fashion, and calculated brain stem extracellular fluid Pco2 and [H+] decreased over the first 80 s both before and after denervation. We speculate that a rapid increase in BBF during acute hypoxia decreases brain stem extracellular fluid Pco2 and [H+], which, in turn, negatively modulate the increase in respiratory drive produced by peripheral chemoreceptor input to the central respiratory generator.

Effect of 2,4-dinitrophenol on the hypometabolic response to hypoxia of conscious adult rats

1997 ◽  
Vol 83 (2) ◽  
pp. 537-542 ◽  
Author(s):  
Chikako Saiki ◽  
Jacopo P. Mortola
Keyword(s):  
Body Temperature ◽  
Oxidative Phosphorylation ◽  
Acute Hypoxia ◽  
Mammalian Species ◽  
Metabolic Effect ◽  
Adult Rats ◽  
Open Flow ◽  
Pharmacological Stimulation ◽  
Before And After ◽  
Mitochondrial Uncoupler

Saiki, Chikako, and Jacopo P. Mortola. Effect of 2,4-dinitrophenol on the hypometabolic response to hypoxia of conscious adult rats. J. Appl. Physiol. 83(2): 537–542, 1997.—During acute hypoxia, a hypometabolic response is commonly observed in many newborn and adult mammalian species. We hypothesized that, if hypoxic hypometabolism were entirely a regulated response with no limitation in O2availability, pharmacological uncoupling of the oxidative phosphorylation should raise O2consumption (V˙o 2) by similar amounts in hypoxia and normoxia. Metabolic, ventilatory, and cardiovascular measurements were collected from conscious rats in air and in hypoxia, both before and after intravenous injection of the mitochondrial uncoupler 2,4-dinitrophenol (DNP). In hypoxia (10% O2 breathing, 60% arterial O2 saturation),V˙o 2, as measured by an open-flow technique, was less than in normoxia (∼80%). Successive DNP injections (6 mg/kg, 4 times) progressively increasedV˙o 2 in both normoxia and hypoxia by similar amounts. Body temperature slightly increased in normoxia, whereas it did not change in hypoxia. The DNP-stimulatedV˙o 2 during hypoxia could even exceed the control normoxic value. A single DNP injection (17 mg/kg iv) had a similar metabolic effect; it also resulted in hypotension and a drop in systemic vascular resistance. We conclude that pharmacological stimulation ofV˙o 2 counteracts theV˙o 2 drop determined by hypoxia and stimulates V˙o 2not dissimilarly from normoxia. Hypoxic hypometabolism is likely to reflect a regulated process of depression of thermogenesis, with no limitation in cellular O2availability.

Ventilatory responses to hypoxia in rats pretreated with nonpeptide NK1 receptor antagonist CP-96,345

1994 ◽  
Vol 76 (4) ◽  
pp. 1528-1532 ◽  
Author(s):  
G. T. De Sanctis ◽  
F. H. Green ◽  
X. Jiang ◽  
M. King ◽  
J. E. Remmers
Keyword(s):  
Ventilatory Response ◽  
Minute Ventilation ◽  
Acute Hypoxia ◽  
Frequency Component ◽  
Nk1 Receptor ◽  
Adult Rats ◽  
Nk1 Receptors ◽  
Before And After ◽  
Sites Of Action

This study reports experiments designed to evaluate the role of neurokinin-1 (NK1) receptors for substance P (SP) in the ventilatory response to acute hypoxia. Ventilation was measured by indirect plethysmography in eight unanesthetized unrestrained adult rats before and after bolus injection of 1, 5, or 10 mg/kg (ip) of CP-96,345 (Pfizer), a potent nonpeptide competitive antagonist of the SP NK1 receptor. Ventilation was measured while the rats breathed air or 8% O2–92% N2 with and without administration of SP antagonist. Pretreatment with CP-96,345 decreased the magnitude of the hypoxic response in a dose-dependent fashion. Minute ventilation in rats pretreated with CP-96,345 was reduced by 22.1% (P < 0.05) at the highest dose (10 mg/kg), largely because of an attenuation of the frequency component. Although both control and treated rats responded to hypoxia with a decrease in duration of inspiration and expiration rats pretreated with CP-96,345 displayed a smaller decrease in inspiration and expiration than control rats (P < 0.05). We have recently shown that neuropeptide-containing fibers are important for mediating the tachypnic response during acute isocapnic hypoxia in rats. The attenuation in minute ventilation at the highest dose (10 mg/kg) is comparable in magnitude to the attenuation observed with neonatal capsaicin treatment, which permanently ablates neuropeptide-containing unmyelinated fibers. Accordingly, this previously reported role of capsaicin-sensitive nerves in the hypoxic ventilatory response of rats is probably attributable to released SP acting at NK1 receptors. One of the likely sites of action of SP antagonists is the carotid body.(ABSTRACT TRUNCATED AT 250 WORDS)

Comparison of the Inhibitory Action of KCl and Guanidine Hydrochloride Solutions on Montmorillonite Swelling

1982 ◽  
Vol 22 (04) ◽  
pp. 514-522 ◽  
Author(s):  
M. Iltis ◽  
G. Didier ◽  
P. Lareal
Keyword(s):  
Potassium Chloride ◽  
Inhibitory Action ◽  
Guanidine Hydrochloride ◽  
Research Work ◽  
Cylindrical Sample ◽  
Degree Of Saturation ◽  
Composition Analysis ◽  
Drilling Mud ◽  
Swelling Clays ◽  
Before And After

Abstract This study compares the effectiveness of potassium chloride with guanidine chlorhydrate in the prevention of-clay swelling. The results given on various swelling tests on calcic montmorillonite led to the conclusions thatguanidine chlorhydrate is more effective than potassium chloride, especially in low concentrations, andwater immersion of samples treated by both solutions shows the permanent feature of the inhibitive action of guanidine chlorhydrate in swelling on one hand and the important increase in swelling of immersed samples treated by potassium chloride on the other. The viscosity measure of montmorillonite suspensions, before and after solution ion elimination by dialysis. confirms these observations. Introduction Among the grounds encountered in drilling, swelling clays are those that raise major problems for wall firmness. These clays, commonly called "gumbos," raise many problems related to swelling, dispersion, and a strong tendency of the cuttings to aggregation. These problems result from the interaction of the drilling mud with the terrain traversed. An analysis of the effectiveness of various materials used in drilling muds to stabilize clayed zones led us to focus on the action of two solutions capable of inhibiting swelling:potassium chloride. which is normally used in drilling wells, andguanidine hydrochloride, which displays a strong fixation tendency on montmorillonite. The purpose of this study is to compare the inhibitory action of these two salts and the influence of their concentration in the solutions by means of relatively simple tests. This research work is limited to treatment of a montmorillonite clay. The Material Investigated To examine the behavior of swelling clays in the presence of the two solutions selected, it would be ideal to carry out tests on samples representative of the horizons that raised problems during drilling operations. However, it is difficult to extract enough clay of stable composition from the cuttings; moreover, the clay is polluted by the drilling mud. Composition analyses of clays that are difficult to drill because of swelling showed that montmorillonite was present in all the samples investigated. Hence this study is limited to an examination of the action of KCl and guanidine hydrochloride on a previously investigated montmorillonite. The montmorillonite used was an Italian natural calcium montmorillonite, supplied untreated and finely ground. The composition analysis carried out in the Compagnie Francaise des Petroles (CFP) laboratory at Bordeaux yielded the results given in Table 1. Table 2 gives the geotechnical properties of the clay investigated. Swelling Tests of Compacted Samples Unidirectional Swelling This test was performed in the measurement cell shown in Fig. 1. The cylindrical sample was hooped laterally and its swelling measured in a single direction. The procedure was as follows.Five grams of clay dried in an oven at 100 deg. C were placed in a measurement cell.The clay was saturated by it KCl or guanidine hydrochloride solution for 24 hours (by filtration) (the degree of saturation measured on some samples after compacting was found to exceed 95%). SPEJ P. 514^

scholarly journals Reproducibility of cardiorespiratory and cellular responses to steady state exercise in hypoxia and preloaded cycling time trial performance reliability in normoxia and acute hypoxia

2015 ◽  
Author(s):  
Ben J Lee ◽  
Charles D Thake
Keyword(s):  
Stress Test ◽  
Acute Hypoxia ◽  
Correlation Coefficients ◽  
Time Trial ◽  
Cellular Responses ◽  
Time Of Day ◽  
Cycling Time Trial ◽  
Hypoxic Conditions ◽  
Before And After ◽  
Cycling Time

Background. The purpose of this study was to assess the reproducibility of cardiorespiratory and cellular (monocyte heat shock protein 70; mHSP70) responses to a fixed load hypoxic stress test (HST) and the reliability of a pre-loaded 16.1km cycling time trial (pTT) conducted under both normoxic and hypoxic conditions. Methods. Eighteen participants (age, 22 ± 4 years; height, 1.77 ± 0.04 meters; body mass, 76.8 kg; estimated body fat and VO2peak = 3.50 ± 0.60 L.min-1) were divided into three groups. Reliability of responses (HR, SPO2, VO2, VCO2, VE and RER) to the HST (FIO2 0.14; 15 minutes rest, 60 minutes cycling at 50% normoxic VO2peak) was assessed across 3 repeat trials (HST 1, 2 and 3, n = 6); mHSP70 was measured via flow cytometry before and after each HST (n = 5); resting HSP was also quantified on 4 separate occasions (n=5). Reliability of the pTT (15 min rest, 40 minutes cycling at 50% normoxic VO2peak) was assessed across 3 repeat normoxic (N; FIO2 ≈ 0.21; n=6) and 3 repeat hypoxic (FIO2 ≈ 0.14; n = 6) trials. All exercise trials were undertaken at the same time of day, following exercise and dietary controls, 7 days apart. Results. Intra-class correlation coefficients (ICC’s) for mean and peak HR, SpO2, VE , VO2 , VCO2 and BLa within each trial were improved from HST1 to HST2 (mean data: 0.99, 0.95, 0.75, 0.62, 0.70, 0.90; peak data: 0.98, 0.96, 0.64, 0.69, 0.74, 0.75) to HST2 and HST3 (ICC = 0.99, 0.97, 0.82, 0.85, 0.87 and 0.96 respectively). mHSP70 was a reproducible at rest without (ICC > 0.95) and with HSTs conducted in the previous 7 days (ICC > 0.95), with no difference in pre to post increases in mHSP70 observed between tests. The reliability for time to pTT completion was improved following one trial, and the CV (test 2 vs. 3) was similar under normoxic (CV = 0.62) and hypoxic conditions (CV = 0.63). Conclusion. Cardiorespiratory and cellular responses to the HST were reproducible and the pTT performance time reliable in both N and H. Since the reproducibility of the measurements in HST trials and reliability of pTT improved between the second and third trials one familiarization visit is recommended prior to employing these protocols in future studies.

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