scholarly journals Peculiarities of the influence of mitochondrial ATP-dependent K+ channels activation on the function of external respiration under experimental pneumonia

2021 ◽  
Vol 67 (6) ◽  
pp. 52-59
Author(s):  
P.K. Tsapenko ◽  
◽  
A.S. Shapovalova ◽  
О.G. Timchenko ◽  
A.N. Golovko ◽  
...  

The studies were performed on male Wistar rats weighing 250-270 with experimental pneumonia (EP) induced by the method of A.M. Kulik. The animals were divided into the following groups: 1 – control; 2 - experimental pneumonia; 3 (first experimental group) - animals, which in parallel with the simulation of pneumonia were intraperitoneally administered uridine at a dose of 0.3 mg/100 g of body weight (daily within 1 week); 4 (second experimental group) - animals in which uridine was administered daily starting from day 4 (at the peak of pneumonia). Animals with EP were examined at 5th (n = 10), 9th (n = 8) and 12th (n = 6) days of the disease development, as well as 1 (n = 5) and 2 (n = 5) months after EP modeling. It was shown that in the first experimental group on the 5th day of EP development, an isoventilator restructuring of respiration was observed. In this group, from day 12 to the end of the study, there was a stenoventilator restructuring of breathing, which was characterized by an increase in tidal volume, alveolar ventilation, oxygen consumption and, accordingly, an increase in oxygen extraction from the alveoli and in the oxygen effect of the respiratory cycle. It can be assumed that in this group, an increase in the intensity of metabolism is provided by the effective activity of the respiratory system. In the second experimental group, isoventilator changes in respiration were observed with a gradual decrease in oxygen consumption and other indicators of the respiratory system efficiency. After 2 months, these changes became significant. Thus, we can talk about significant differences in the effect of uridine on the function of external respiration (i.e., apparently, on the activity of the mitochondrial ATP-dependent K+ channel) during EP, which depended on the period of onset of uridine administration. Application of uridine immediately (1st experimental group) looks more effective and even has a stimulating effect on the respiratory function over a long period of experiment. The administration of uridine starting from the 4 partially normalizes the respiration parameters. However, after 1 month there is a depression of the functions of the respiratory system, which, probably, may further worsen. The reasons for the differences in the identified dynamics require further investigation.

2021 ◽  
Author(s):  
A.V. Shulepov ◽  
I.A. Shperling ◽  
Yu.V. Yurkevich ◽  
N.V. Shperling

The experiments were performed on 280 male Wistar rats weighing 300-340 g. The design of the study included: modeling of compression injury of the soft tissues of the thigh, local injection of the preparation of hyaluronic acid "Gialift 3.5" into the area of damage 3 hours after the cessation of compression, taking into account the results after 7, 14 and 28 days. The introduction of hyaluronic acid into the area of compression injury of soft tissues reduces the severity of myoglobinemia, increases the immunohistochemical density of VEGF-positive cells, improves the perfusion characteristics of microcirculation, oxygen saturation, and specific oxygen consumption by tissues. Keywords: traumatic muscle ischemia, hyaluronic acid, myoglobin, microcirculation, metabolism, laser Doppler flowmetry, morphometry.


2011 ◽  
Vol 26 (6) ◽  
pp. 426-432
Author(s):  
Reginaldo Inojosa Carneiro Campello ◽  
Belmiro Cavalcanti do Egito Vasconcelos ◽  
Gerhilde Callou Sampaio ◽  
Antonio Rolim ◽  
Gabriela Granja Porto

PURPOSE: To evaluate the bone healing of mandibular fractures following the use of Portland cement. METHODS: Thirty-two male Wistar rats were divided into control and experimental groups. In the control group the rats were submitted to a mandibular fracture, which was reduced, and the soft tissues were sutured. In the experimental group the rats had the mandibular fracture reduced and maintained with the Portland cement. The animals were euthanized 7 and 21 days after surgery by injecting a lethal dose of anesthetic. The following variables were studied: weight of the animals, radiographic images, histopathological features and time of surgery. RESULTS: A weight loss was observed in the specimens of both groups at the different times of evaluation, a greater difference in weight before and after surgery being found in the experimental group, which was statistically significant (p <0.05, p = 0.041). From the histological point of view, with a margin of error (5.0%) the only two significant differences (p <0.05) recorded in the variables were "Material deployed" and "Bone resorption" during the evaluations at 7 and 21 days, respectively. CONCLUSION: The Portland cement served to promote bone healing.


2015 ◽  
pp. 153-159 ◽  
Author(s):  
M. M. GOVENDER ◽  
A. NADAR

Oxidative stress is an imbalance between free radicals and antioxidants, and is an important etiological factor in the development of hypertension. Recent experimental evidence suggests that subpressor doses of angiotensin II elevate oxidative stress and blood pressure. We aimed to investigate the oxidative stress related mechanism by which a subpressor dose of angiotensin II induces hypertension in a normotensive rat model. Normotensive male Wistar rats were infused with a subpressor dose of angiotensin II for 28 days. The control group was sham operated and infused with saline only. Plasma angiotensin II and H2O2 levels, whole-blood glutathione peroxidase, and AT-1a, Cu/Zn SOD, and p22phox mRNA expression in the aorta was assessed. Systolic and diastolic blood pressures were elevated in the experimental group. There was no change in angiotensin II levels, but a significant increase in AT-1a mRNA expression was found in the experimental group. mRNA expression of p22phox was increased significantly and Cu/Zn SOD decreased significantly in the experimental group. There was no significant change to the H2O2 and GPx levels. Angiotensin II manipulates the free radical-antioxidant balance in the vasculature by selectively increasing O2− production and decreasing SOD activity and causes an oxidative stress induced elevation in blood pressure in the Wistar rat.


2017 ◽  
Vol 10 (4) ◽  
pp. 269-276
Author(s):  
B S Sukovatykh ◽  
A Y Grigoryan ◽  
A I Bezhin ◽  
T A Pankrusheva ◽  
Yu Yu Blinkov ◽  
...  

Relevance. Purulent complications occur in 35-45% of patients with surgical diseases, lethality rate from these conditions achieves 25%. The purpose of the study. To investigate the wound process while treating the purulent wounds with immobilized forms of miramistin and benzalkonium chloride in gel of sodium salt of carboxymetylcellulose. Materials and methods. There were analysed results of experimental study of the wound process on 108 male Wistar rats. Experimental animals were divided into 3 groups, each group included 36 rats. In a comparison group ‘Levomekol’ ointment was used for treatment. In the first experimental group treatment was done by the ointment with the following composition: 0,01% solution of miramistin — 100 g, metronidazol –1,0 g, sodium salt of carboxymetylcellulose — 4,0 g, while in the second experimental group ointment composition included benzalkonium chloride 0,02 g, metronidazol — 1,0 g, sodium salt of carboxymetylcellulose — 4,0 g, purified water — up to 100,0 g. The wound process was evaluated by planimetric, microbiological and histological methods of investigation. Results and its discussion. The reduction of wound area in the first experimental group was higher than in a comparison group on the 3rd day of the experiment by 9,7%, on the 5th day — by 7,6%, on the 10th and 15th days — by 10,5%, while in the second experimental group the change was 37,2%, 27,3%, 13,8% and 6,9% respectively. In the first experimental group microbial contamination of the wound was less than in a comparison group by 5,8х106, on the 5th day — by 3,1х105, on the 10th day — by 6,1х104, while in the second experimental group on the 3rd day there were no differences, on the 5th day — by 6,3х105, on the 10th day — 1,1х104. Histological investigations of the wound biopsies on the 10th day of experiment showed that in a comparison group the bottom of the wound was covered by granulation tissue without signs of epithelization, there was full coverage of the wound with a newly formed epithelium in experimental groups. Conclusions. The use of prolonged quaternary ammonium antiseptics in treatment of purulent wounds is pathogenetically justified and efficient.


2016 ◽  
Vol 45 (5) ◽  
pp. 258-264 ◽  
Author(s):  
Liciane dos Santos MENEZES ◽  
Liane Maciel de Almeida SOUZA ◽  
Márcio Roberto Viana dos SANTOS ◽  
Patrícia Santos Cunha MENDONÇA ◽  
Ítalo José Alves MOREIRA ◽  
...  

Abstract Introduction Levobupivacaine (LEVO) can replace analgesia because it exhibits low toxicity and causes minor vasoconstriction, enabling its use in patients in whom vasoconstrictors are contraindicated. Objective We aimed to evaluate the effects of LEVO in isolated rat superior mesenteric artery by using the vascular reactivity technique and compare its effect to that of lidocaine. Material and method Arterial rings were obtained from the mesenteric artery of male Wistar rats and kept in organ baths. For recording isometric contractions, each ring was suspended by cotton threads from a force transducer, which was connected to a data acquisition system. Result Both lidocaine and LEVO did not show a vasoconstrictor effect on the basal tone of the arterial rings with functional endothelium. However, when the rings were pre-contracted with phenylephrine, both drugs were able to induce concentration-dependent vasodilatation. The vasodilator effect induced by LEVO did not change after removal of the endothelium, or with the addition of tetraethylammonium (1 mM), a non-selective K+ channel blocker. In the rings without functional endothelium, which were pre-contracted with depolarizing Tyrode’s solution (KCl 80 mM), LEVO-induced vasodilatation was not significantly different from that observed in the rings pre-contracted with phenylephrine. Moreover, it did not show a significant additional vasodilator effect compared to the maximal vasodilator effect of nifedipine. Conclusion This study demonstrated that LEVO produces a vasodilator effect in the rat superior mesenteric artery in an endothelium-independent manner. This effect seems to be mediated via Ca2+ channel blockade in the vascular smooth muscle cells.


2013 ◽  
Vol 18 (4) ◽  
pp. 113-119 ◽  
Author(s):  
Milena Peixoto Nogueira de Sá ◽  
Jacqueline Nelisis Zanoni ◽  
Carlos Luiz Fernandes de Salles ◽  
Fabrício Dias de Souza ◽  
Uhana Seifert Guimarães Suga ◽  
...  

INTRODUCTION: The mandibular condylar surface is made up of four layers, i.e., an external layer composed of dense connective tissue, followed by a layer of undifferentiated cells, hyaline cartilage and bone. Few studies have demonstrated the behavior of the condylar cartilage when the mandible is positioned posteriorly, as in treatments for correcting functional Class III malocclusion. OBJECTIVE: The aim of this study was to assess the morphologic and histological aspects of rat condyles in response to posterior positioning of the mandible. METHODS: Thirty five-week-old male Wistar rats were selected and randomly divided into two groups: A control group (C) and an experimental group (E) which received devices for inducing mandibular retrusion. The animals were euthanized at time intervals of 7, 21 and 30 days after the experiment had began. For histological analysis, total condylar thickness was measured, including the proliferative, hyaline and hypertrophic layers, as well as each layer separately, totaling 30 measurements for each parameter of each animal. RESULTS: The greatest difference in cartilage thickness was observed in 21 days, although different levels were observed in the other periods. Group E showed an increase of 39.46% in the total layer, reflected by increases in the thickness of the hypertrophic (42.24%), hyaline (46.92%) and proliferative (17.70%) layers. CONCLUSIONS: Posteriorly repositioning the mandible produced a series of histological and morphological responses in the condyle, suggesting condylar and mandibular adaptation in rats.


2009 ◽  
Vol 79 (5) ◽  
pp. 978-983 ◽  
Author(s):  
Takayoshi Ishida ◽  
Tadachika Yabushita ◽  
Kunimichi Soma

Abstract Objective: To determine the influence of masseter muscle activity during growth on the functional characteristics of temporomandibular joint (TMJ) mechanoreceptors. Materials and Methods: Sixty-six 3-week-old male Wistar rats were divided into an experimental group, in which the masseter muscles were bilaterally resected at 3 weeks of age, and a control group. Single-unit activities of the TMJ mechanoreceptors were evoked by indirect stimulation of passive jaw movement. Electrophysiologic recordings of TMJ units were made at 5, 7, and 9 weeks of age. Results: During this period, the firing threshold of the TMJ units was significantly lower and the maximum instantaneous frequency of the TMJ units was significantly higher in the experimental group than in the control group. Conclusion: Reduced masseter activity during the growth period alters the response properties of TMJ mechanoreceptors.


2014 ◽  
Vol 19 (1) ◽  
pp. 36-40 ◽  
Author(s):  
Meaghan E. Maddigan ◽  
David G. Behm ◽  
Glen R. Belfry

Context:High intensity interval training (HIIT) has been shown to improve muscle power and endurance, as well as aerobic power.Objective:To assess the effects of HIIT that utilizes resistive elastic bands to improve overhand throwing velocity.Participants:Healthy female volunteers (n = 13) ranging in age from 18–29 years.Interventions:Participants were randomly assigned to either a control group or an experimental group that exercised 3 days per week for 3 weeks. Each training session involved performance of 5 sets of 20 throwing motions against elastic band resistance, which was performed by both extremities.Main Outcome Measures:Maximal oxygen consumption was measured during performance of a graded exercise test that utilized an upper extremity cycle ergometer. A radar gun was used to assess peak throwing velocity and the extent to which throwing velocity was sustained during performance of a 20-throw endurance test.Results:After completing the training, the experimental group exhibited faster peak throwing velocity (61.6 ± 6.6 km/hr to 63.2 ± 8.6 km/hr) and a reduced fatigue index (1.18 ± 0.16 to 1.01 ± 0.02). Training also resulted in a 14% improvement in maximum oxygen consumption (1.40 ± 0.46 L/min to 1.60 ± 0.49 L/ min) and longer time to fatigue (9.99 ± 1.84 min to 11.43 ± 2.29 min).Conclusion:The high-intensity interval training program was effective for improvement of overhand throwing performance.


2019 ◽  
Vol 2 (1) ◽  
pp. 8-13
Author(s):  
Iryanov Yu.M ◽  
Kiryanov N.A

Aim To study the chondroplasty efficacy of the bone matrix obtained using an original technology in restoring cartilage defect of the knee joint. Material and Methods Marginal defects were modeled on the surface of the distal end of the femur in 40 adult male Wistar rats. The bone matrix obtained using an original technology was implanted in the damaged area in animals of the experimental group. Material was investigated by means of light microscopy, transmission and scanning electron microscopy, and electron probe X-ray microanalysis. Results It was found that the bone matrix implanted did not cause an immune rejection reaction, activated reparative chondrogenesis for a prolonged period. In the area of articular cartilage lesion, the regenerate acquiring cellular and histochemical characteristics of the hyaline cartilage tissue was formed. The chondroinductive properties for the bone matrix were ensured by localized growth factors and morphogenetic proteins released during osteoclastic resorption. Conclusion The application of the bone matrix as a stimulator of chondrogenesis is theoretically reasonable and has a good perspective in treatment of damages and diseases of the articular cartilage.


BIO-PEDAGOGI ◽  
2013 ◽  
Vol 2 (2) ◽  
pp. 45
Author(s):  
Renita Yuliana ◽  
Puguh Karyanto ◽  
Marjono Marjono

<div class="WordSection1"><p>The purpose of this research is to ascertain the influence utilization concept map in constructivisme type Novick model to overcome misconception on the concept of the human respiratory system. The research was quasi experiment research using quantitative approach. The research was designed using post-test only with nonequivalent group design. The sample of this research was established by cluster sampling. The populations of this research were all of 11<sup>th</sup> degree students of science at SMA Negeri 2 Karanganyar in academic year 2012/2013. The samples of this research were the students of 11th Imersi I as experiment group and 11<sup>th</sup> Imersi II as control group. The data was collected using reasoning multiple choice test and observation form. The hypotheses analyzed by t-test. The research concluded that application of utilization concept map in constructivisme type Novick model didn’t influence on the efforts to overcome the misconceptions on the concept of the human respiratory system with the misconception degree that revealed unti 3,2% in the experimental group.</p><p align="center"> </p><p class="0jTULISANKATAKUNCIKEYWORDS">Key Words: Concept map, constructivisme type Novick model, misconception, the human respiratory system</p></div>


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