scholarly journals Study of Endothelio- and Osteoprotective Effects of Combination of Rosuvastatin with L-Norvaline in Experiment

2018 ◽  
Vol 2018 ◽  
pp. 1-4 ◽  
Author(s):  
M. S. Sobolev ◽  
A. V. Faitelson ◽  
O. S. Gudyrev ◽  
D. S. R. Rajkumar ◽  
G. M. Dubrovin ◽  
...  
Keyword(s):  
Endothelial Dysfunction ◽  
Bone Tissue ◽  
Wistar Rats ◽  
Microcirculatory Bed ◽  
Experimental Osteoporosis ◽  
Bone Trabeculae

The experiment was carried out on 120 female white Wistar rats, to study the endothelio- and osteoprotective action of the combination of rosuvastatin with L-norvaline in the model of experimental osteoporosis. It was found that, after ovariectomy in rats, endothelial dysfunction of the vessels of the microcirculatory bed of bone tissue develops, leading to the appearance of osteoporosis, but the combination of the studied drugs prevents the decrease in the level of microcirculation in the bone tissue, thereby preventing the thinning of bone trabeculae and preventing the occurrence of microfractures in them.

Comparative Assessment of Endothelium-Associated Correction of Experimental Osteoporosis with Resveratrol and Etoksidol

2012 ◽  
Vol 19 (1) ◽  
pp. 8-11
Author(s):  
Aleksandr Vladimirovich Faytel'son ◽  
G M Dubrovin ◽  
O S Gudyrev ◽  
M V Pokrovskiy ◽  
A V Ivanov ◽  
...  
Keyword(s):  
Endothelial Dysfunction ◽  
Bone Tissue ◽  
Bone Remodeling ◽  
Wistar Rats ◽  
Comparative Assessment ◽  
Experimental Osteoporosis ◽  
Female Wistar Rats ◽  
Bone Trabeculae

Osteoprotective action of resveratrol and etoksidol was studied on the model of experimental osteoporosis (140 female Wistar rats). It was detected that endothelial dysfunction of bone tissue microcirculation bed that led to osteoporosis development. In contrast to etoksidol, resveratrol prevented the reduction of bone tissue microcirculation level and the aggravation of bone remodeling processes in developing osteoporosis that was manifested by delayed bone trabeculae thinning and averting of microfractures in them.

Parmacologic Correction in Experimental Osteoporosis and Osteoporotic Fractures

2010 ◽  
Vol 17 (3) ◽  
pp. 47-51
Author(s):  
Aleksandr Vladimirovich Faytel'son ◽  
G M Dubrovin ◽  
O S Gudyrev ◽  
M V Pokrovskiy ◽  
A V Ivanov ◽  
...  
Keyword(s):  
Fracture Healing ◽  
Bone Tissue ◽  
Wistar Rats ◽  
Healing Rate ◽  
Vascular Dysfunction ◽  
Osteoporotic Fractures ◽  
Slowing Down ◽  
Experimental Osteoporosis ◽  
Female Wistar Rats ◽  
Experimental Fracture Healing

Osteoprotective effect of enalapril and losartan was studied using experimental model of osteoporosis and osteoporotic fractures (222 female Wistar rats). It was detected that in rats after ovariectomy endothelial vascular dysfunction of microcirculation in bone tissue bed developed. Those changes caused osteoporosis and delayed experimental fracture healing. Enalapril and losartan prevented the decrease of microcirculation level in bone tissue that promoted slowing-down of osseous trabecula thinning, prevented microfractures and increased the healing rate of experimental fractures.

scholarly journals Comparative Evaluation of Enalapril and Losartan in Pharmacological Correction of Experimental Osteoporosis and Fractures of Its Background

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
D. S. R. Rajkumar ◽  
A. V. Faitelson ◽  
O. S. Gudyrev ◽  
G. M. Dubrovin ◽  
M. V. Pokrovski ◽  
...  
Keyword(s):  
Endothelial Dysfunction ◽  
Comparative Evaluation ◽  
Osteoporotic Fractures ◽  
Experimental Models ◽  
Female Rats ◽  
Experimental Osteoporosis ◽  
Pharmacological Correction ◽  
Bone Trabeculae

In the experiment on the white Wistar female rats (222 animals), the osteoprotective effect of enalapril and losartan was studied on experimental models of osteoporosis and osteoporotic fractures. It was revealed that in rats after ovariectomy, the endothelial dysfunction of microcirculation vessels of osteal tissue develops, resulting in occurrence of osteoporosis and delay of consolidation of experimental fractures. Enalapril and losartan prevented the reduction of microcirculation in bone, which was reflected in slowing the thinning of bone trabeculae and in preventing the occurrence of these microfractures, as well as increasing quality of experimental fractures healing.

scholarly journals Erythropoietin Mimetic Peptide (pHBSP) Corrects Endothelial Dysfunction in a Rat Model of Preeclampsia

2020 ◽  
Vol 21 (18) ◽  
pp. 6759 ◽  
Author(s):  
Mikhail Korokin ◽  
Vladimir Gureev ◽  
Oleg Gudyrev ◽  
Ivan Golubev ◽  
Liliya Korokina ◽  
...  
Keyword(s):  
Endothelial Dysfunction ◽  
Wistar Rats ◽  
Severe Disease ◽  
Late Pregnancy ◽  
New Drugs ◽  
Greater Omentum ◽  
Large Role ◽  
Morphological Pattern ◽  
Fetoplacental Complex ◽  
Prevention And Therapy

Preeclampsia is a severe disease of late pregnancy. Etiological factors and a pathogenetic pattern of events still require significant clarification, but it is now recognized that a large role is played by placentation disorders and emerging endothelial dysfunction. The administration of short-chain peptides mimicking the spatial structure of the B erythropoietin chain may become one of the directions of searching for new drugs for preeclampsia prevention and therapy. Simulation of ADMA-like preeclampsia in Wistar rats was performed by the administration of a non-selective NOS blocker L-NAME from the 14th to 20th day of pregnancy. The administration of the pHBSP at the doses of 10 µg/kg and 250 µg/kg corrected the established morphofunctional disorders. The greatest effect was observed at a dose of 250 µg/kg. There was a decrease in systolic and diastolic blood pressure by 31.2 and 32.8%, respectively (p < 0.0001), a decrease in the coefficient of endothelial dysfunction by 48.6% (p = 0.0006), placental microcirculation increased by 82.8% (p < 0.0001), the NOx concentration was increased by 42,6% (p = 0.0003), the greater omentum edema decreased by 11.7% (p = 0.0005) and proteinuria decreased by 76.1% (p < 0.0002). In addition, there was an improvement in the morphological pattern of the fetoplacental complex and the ratio of BAX to Bcl-2 expression which characterizes the apoptotic orientation of the cells.

Change of Biomechanical Parameters in the Lower Jaws of Rabbits with Experimental Osteoporosis after Implantation of Calcium-Phosphate Bioceramic Material in the Greater Trochanter Region

2016 ◽  
Vol 721 ◽  
pp. 224-228
Author(s):  
Girts Salms ◽  
Vladislavs Ananjevs ◽  
Vladimirs Kasyanovs ◽  
Andrejs Skagers ◽  
Ilze Salma ◽  
...  
Keyword(s):  
Bone Tissue ◽  
Tricalcium Phosphate ◽  
Strontium Ranelate ◽  
Biomechanical Properties ◽  
Control Group ◽  
Greater Trochanter ◽  
Lower Jaw ◽  
Experimental Osteoporosis ◽  
Rabbit Bone ◽  
Biomechanical Parameters

Investigation of biomechanical properties of the rabbit bone tissue from a corner of the lower jaw was done. Experimental osteoporosis was induced by ovariectomy and following injections of methylprednisolone. The defects in the greater trochanter region was created and filled with granules of a hydroxyapatite and tricalcium phosphate (HAP/TCP 30/70) or HAP/TCP 30/70 together with 5% strontium ranelate. After 3 month animals were euthanased, squared samples have been cut out from a corner of the lower jaw and tested on a bend. Results of research show, that the corner of a lower jaw in rabbit becomes more rigid after filling of defects in the greater trochanter region with granules of a hydroxyapatite and tricalcium phosphate (HAP/TCP 30/70) or granules together with strontium ranelate. The ultimate strain for the bone tissue in the 2nd and 3rd group is less, than for control group. Thus, local uses calcium – phosphatic bioceramic material around the greater trochanter region improves biomechanical parameters of a bone tissue in the lower jaw of animals.

scholarly journals A two-layer elasto-visco-plastic rheological model for the material parameter identification of bone tissue

2020 ◽  
Vol 19 (6) ◽  
pp. 2149-2162 ◽  
Author(s):  
Andreas G. Reisinger ◽  
Martin Frank ◽  
Philipp J. Thurner ◽  
Dieter H. Pahr
Keyword(s):  
Yield Stress ◽  
Bone Tissue ◽  
Loss Tangent ◽  
Material Properties ◽  
Rheological Model ◽  
Mechanical Test ◽  
Mechanical Tests ◽  
Material Parameter Identification ◽  
Young’S Moduli ◽  
Bone Trabeculae

Abstract The ability to measure bone tissue material properties plays a major role in diagnosis of diseases and material modeling. Bone’s response to loading is complex and shows a viscous contribution to stiffness, yield and failure. It is also ductile and damaging and exhibits plastic hardening until failure. When performing mechanical tests on bone tissue, these constitutive effects are difficult to quantify, as only their combination is visible in resulting stress–strain data. In this study, a methodology for the identification of stiffness, damping, yield stress and hardening coefficients of bone from a single cyclic tensile test is proposed. The method is based on a two-layer elasto-visco-plastic rheological model that is capable of reproducing the specimens’ pre- and postyield response. The model’s structure enables for capturing the viscously induced increase in stiffness, yield, and ultimate stress and for a direct computation of the loss tangent. Material parameters are obtained in an inverse approach by optimizing the model response to fit the experimental data. The proposed approach is demonstrated by identifying material properties of individual bone trabeculae that were tested under wet conditions. The mechanical tests were conducted according to an already published methodology for tensile experiments on single trabeculae. As a result, long-term and instantaneous Young’s moduli were obtained, which were on average 3.64 GPa and 5.61 GPa, respectively. The found yield stress of 16.89 MPa was lower than previous studies suggest, while the loss tangent of 0.04 is in good agreement. In general, the two-layer model was able to reproduce the cyclic mechanical test data of single trabeculae with an root-mean-square error of 2.91 ± 1.77 MPa. The results show that inverse rheological modeling can be of great advantage when multiple constitutive contributions shall be quantified based on a single mechanical measurement.

scholarly journals Loss of trabeculae by mechano-biological means may explain rapid bone loss in osteoporosis

2008 ◽  
Vol 5 (27) ◽  
pp. 1243-1253 ◽  
Author(s):  
Brianne M Mulvihill ◽  
Laoise M McNamara ◽  
Patrick J Prendergast
Keyword(s):  
Trabecular Bone ◽  
Bone Tissue ◽  
Bone Fragility ◽  
Osteoporotic Bone ◽  
Single Fracture ◽  
Rapid Loss ◽  
Fracture Event ◽  
Turnover Process ◽  
Trabecular Bone Mass ◽  
Bone Trabeculae

Osteoporosis is characterized by rapid and irreversible loss of trabecular bone tissue leading to increased bone fragility. In this study, we hypothesize two causes for rapid loss of bone trabeculae; firstly, the perforation of trabeculae is caused by osteoclasts resorbing a cavity so deep that it cannot be refilled and, secondly, the increases in bone tissue elastic modulus lead to increased propensity for trabecular perforation. These hypotheses were tested using an algorithm that was based on two premises: (i) bone remodelling is a turnover process that repairs damaged bone tissue by resorbing and returning it to a homeostatic strain level and (ii) osteoblast attachment is under biochemical control. It was found that a mechano-biological algorithm based on these premises can simulate the remodelling cycle in a trabecular strut where damaged bone is resorbed to form a pit that is subsequently refilled with new bone. Furthermore, the simulation predicts that there is a depth of resorption cavity deeper than which refilling of the resorption pits is impossible and perforation inevitably occurs. However, perforation does not occur by a single fracture event but by continual removal of microdamage after it forms beneath the resorption pit. The simulation also predicts that perforations would occur more easily in trabeculae that are more highly mineralized (stiffer). Since both increased osteoclast activation rates and increased mineralization have been measured in osteoporotic bone, either or both may contribute to the rapid loss of trabecular bone mass observed in osteoporotic patients.

Possibilities of in vivo validation of a model of experimental osteoporosis

2020 ◽  
Vol 18 (4) ◽  
pp. 365-367
Author(s):  
Alekber A. Bairamov ◽  
Nailya Sh. Mamina ◽  
Tatiana L. Karonova ◽  
Petr D. Shabanov
Keyword(s):  
Bone Tissue ◽  
Experimental Model ◽  
X Ray ◽  
Experimental Osteoporosis ◽  
In Vivo Validation

In this work, the possibilities ofin vivovalidation of an experimental model of osteoporosis are analyzed. Themodel is based on the application of biochemical methodsforanalyzing predictors of osteoporosis inbloodserum,andtheirinformative value in the comparativeanalysis of the assessment of the degree of osteoporosisbasedoninstrumental studies of autopsy of bone tissue usingatomicabsorption spectroscopy and x-ray densitometry.

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